Merge tag 'for-linus-4.12b-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Xen fixes and featrues for 4.12. The main changes are:

   - enable building the kernel with Xen support but without enabling
     paravirtualized mode (Vitaly Kuznetsov)

   - add a new 9pfs xen frontend driver (Stefano Stabellini)

   - simplify Xen's cpuid handling by making use of cpu capabilities
     (Juergen Gross)

   - add/modify some headers for new Xen paravirtualized devices
     (Oleksandr Andrushchenko)

   - EFI reset_system support under Xen (Julien Grall)

   - and the usual cleanups and corrections"

* tag 'for-linus-4.12b-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (57 commits)
  xen: Move xen_have_vector_callback definition to enlighten.c
  xen: Implement EFI reset_system callback
  arm/xen: Consolidate calls to shutdown hypercall in a single helper
  xen: Export xen_reboot
  xen/x86: Call xen_smp_intr_init_pv() on BSP
  xen: Revert commits da72ff5bfcb0 and 72a9b186292d
  xen/pvh: Do not fill kernel's e820 map in init_pvh_bootparams()
  xen/scsifront: use offset_in_page() macro
  xen/arm,arm64: rename __generic_dma_ops to xen_get_dma_ops
  xen/arm,arm64: fix xen_dma_ops after 815dd18 "Consolidate get_dma_ops..."
  xen/9pfs: select CONFIG_XEN_XENBUS_FRONTEND
  x86/cpu: remove hypervisor specific set_cpu_features
  vmware: set cpu capabilities during platform initialization
  x86/xen: use capabilities instead of fake cpuid values for xsave
  x86/xen: use capabilities instead of fake cpuid values for x2apic
  x86/xen: use capabilities instead of fake cpuid values for mwait
  x86/xen: use capabilities instead of fake cpuid values for acpi
  x86/xen: use capabilities instead of fake cpuid values for acc
  x86/xen: use capabilities instead of fake cpuid values for mtrr
  x86/xen: use capabilities instead of fake cpuid values for aperf
  ...

7 files changed, 2293 insertions, 36 deletions

diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h
index 95ce6ac3a971..b1b4ecdf329a 100644
--- a/include/xen/arm/page-coherent.h
+++ b/include/xen/arm/page-coherent.h
@@ -2,8 +2,16 @@
 #define _ASM_ARM_XEN_PAGE_COHERENT_H
 
 #include <asm/page.h>
+#include <asm/dma-mapping.h>
 #include <linux/dma-mapping.h>
 
+static inline const struct dma_map_ops *xen_get_dma_ops(struct device *dev)
+{
+	if (dev && dev->archdata.dev_dma_ops)
+		return dev->archdata.dev_dma_ops;
+	return get_arch_dma_ops(NULL);
+}
+
 void __xen_dma_map_page(struct device *hwdev, struct page *page,
 	     dma_addr_t dev_addr, unsigned long offset, size_t size,
 	     enum dma_data_direction dir, unsigned long attrs);
@@ -19,13 +27,13 @@ void __xen_dma_sync_single_for_device(struct device *hwdev,
 static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
 		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
 {
-	return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
+	return xen_get_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
 }
 
 static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
 		void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
 {
-	__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
+	xen_get_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
 }
 
 static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
@@ -49,7 +57,7 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
 	 * specific function.
 	 */
 	if (local)
-		__generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+		xen_get_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
 	else
 		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
 }
@@ -67,8 +75,8 @@ static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
 	 * specific function.
 	 */
 	if (pfn_valid(pfn)) {
-		if (__generic_dma_ops(hwdev)->unmap_page)
-			__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
+		if (xen_get_dma_ops(hwdev)->unmap_page)
+			xen_get_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
 	} else
 		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
 }
@@ -78,8 +86,8 @@ static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
 {
 	unsigned long pfn = PFN_DOWN(handle);
 	if (pfn_valid(pfn)) {
-		if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
-			__generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
+		if (xen_get_dma_ops(hwdev)->sync_single_for_cpu)
+			xen_get_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
 	} else
 		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
 }
@@ -89,8 +97,8 @@ static inline void xen_dma_sync_single_for_device(struct device *hwdev,
 {
 	unsigned long pfn = PFN_DOWN(handle);
 	if (pfn_valid(pfn)) {
-		if (__generic_dma_ops(hwdev)->sync_single_for_device)
-			__generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+		if (xen_get_dma_ops(hwdev)->sync_single_for_device)
+			xen_get_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
 	} else
 		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
 }
diff --git a/include/xen/interface/io/9pfs.h b/include/xen/interface/io/9pfs.h
new file mode 100644
index 000000000000..5b6c19dae5e2
--- /dev/null
+++ b/include/xen/interface/io/9pfs.h
@@ -0,0 +1,36 @@
+/*
+ * 9pfs.h -- Xen 9PFS transport
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Copyright (C) 2017 Stefano Stabellini <stefano@aporeto.com>
+ */
+
+#ifndef __XEN_PUBLIC_IO_9PFS_H__
+#define __XEN_PUBLIC_IO_9PFS_H__
+
+#include "xen/interface/io/ring.h"
+
+/*
+ * See docs/misc/9pfs.markdown in xen.git for the full specification:
+ * https://xenbits.xen.org/docs/unstable/misc/9pfs.html
+ */
+DEFINE_XEN_FLEX_RING_AND_INTF(xen_9pfs);
+
+#endif
diff --git a/include/xen/interface/io/displif.h b/include/xen/interface/io/displif.h
new file mode 100644
index 000000000000..596578d9be3e
--- /dev/null
+++ b/include/xen/interface/io/displif.h
@@ -0,0 +1,854 @@
+/******************************************************************************
+ * displif.h
+ *
+ * Unified display device I/O interface for Xen guest OSes.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Copyright (C) 2016-2017 EPAM Systems Inc.
+ *
+ * Authors: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ *          Oleksandr Grytsov <oleksandr_grytsov@epam.com>
+ */
+
+#ifndef __XEN_PUBLIC_IO_DISPLIF_H__
+#define __XEN_PUBLIC_IO_DISPLIF_H__
+
+#include "ring.h"
+#include "../grant_table.h"
+
+/*
+ ******************************************************************************
+ *                           Protocol version
+ ******************************************************************************
+ */
+#define XENDISPL_PROTOCOL_VERSION	"1"
+
+/*
+ ******************************************************************************
+ *                  Main features provided by the protocol
+ ******************************************************************************
+ * This protocol aims to provide a unified protocol which fits more
+ * sophisticated use-cases than a framebuffer device can handle. At the
+ * moment basic functionality is supported with the intention to be extended:
+ *  o multiple dynamically allocated/destroyed framebuffers
+ *  o buffers of arbitrary sizes
+ *  o buffer allocation at either back or front end
+ *  o better configuration options including multiple display support
+ *
+ * Note: existing fbif can be used together with displif running at the
+ * same time, e.g. on Linux one provides framebuffer and another DRM/KMS
+ *
+ * Note: display resolution (XenStore's "resolution" property) defines
+ * visible area of the virtual display. At the same time resolution of
+ * the display and frame buffers may differ: buffers can be smaller, equal
+ * or bigger than the visible area. This is to enable use-cases, where backend
+ * may do some post-processing of the display and frame buffers supplied,
+ * e.g. those buffers can be just a part of the final composition.
+ *
+ ******************************************************************************
+ *                        Direction of improvements
+ ******************************************************************************
+ * Future extensions to the existing protocol may include:
+ *  o display/connector cloning
+ *  o allocation of objects other than display buffers
+ *  o plane/overlay support
+ *  o scaling support
+ *  o rotation support
+ *
+ ******************************************************************************
+ *                  Feature and Parameter Negotiation
+ ******************************************************************************
+ *
+ * Front->back notifications: when enqueuing a new request, sending a
+ * notification can be made conditional on xendispl_req (i.e., the generic
+ * hold-off mechanism provided by the ring macros). Backends must set
+ * xendispl_req appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()).
+ *
+ * Back->front notifications: when enqueuing a new response, sending a
+ * notification can be made conditional on xendispl_resp (i.e., the generic
+ * hold-off mechanism provided by the ring macros). Frontends must set
+ * xendispl_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()).
+ *
+ * The two halves of a para-virtual display driver utilize nodes within
+ * XenStore to communicate capabilities and to negotiate operating parameters.
+ * This section enumerates these nodes which reside in the respective front and
+ * backend portions of XenStore, following the XenBus convention.
+ *
+ * All data in XenStore is stored as strings. Nodes specifying numeric
+ * values are encoded in decimal. Integer value ranges listed below are
+ * expressed as fixed sized integer types capable of storing the conversion
+ * of a properly formated node string, without loss of information.
+ *
+ ******************************************************************************
+ *                        Example configuration
+ ******************************************************************************
+ *
+ * Note: depending on the use-case backend can expose more display connectors
+ * than the underlying HW physically has by employing SW graphics compositors
+ *
+ * This is an example of backend and frontend configuration:
+ *
+ *--------------------------------- Backend -----------------------------------
+ *
+ * /local/domain/0/backend/vdispl/1/0/frontend-id = "1"
+ * /local/domain/0/backend/vdispl/1/0/frontend = "/local/domain/1/device/vdispl/0"
+ * /local/domain/0/backend/vdispl/1/0/state = "4"
+ * /local/domain/0/backend/vdispl/1/0/versions = "1,2"
+ *
+ *--------------------------------- Frontend ----------------------------------
+ *
+ * /local/domain/1/device/vdispl/0/backend-id = "0"
+ * /local/domain/1/device/vdispl/0/backend = "/local/domain/0/backend/vdispl/1/0"
+ * /local/domain/1/device/vdispl/0/state = "4"
+ * /local/domain/1/device/vdispl/0/version = "1"
+ * /local/domain/1/device/vdispl/0/be-alloc = "1"
+ *
+ *-------------------------- Connector 0 configuration ------------------------
+ *
+ * /local/domain/1/device/vdispl/0/0/resolution = "1920x1080"
+ * /local/domain/1/device/vdispl/0/0/req-ring-ref = "2832"
+ * /local/domain/1/device/vdispl/0/0/req-event-channel = "15"
+ * /local/domain/1/device/vdispl/0/0/evt-ring-ref = "387"
+ * /local/domain/1/device/vdispl/0/0/evt-event-channel = "16"
+ *
+ *-------------------------- Connector 1 configuration ------------------------
+ *
+ * /local/domain/1/device/vdispl/0/1/resolution = "800x600"
+ * /local/domain/1/device/vdispl/0/1/req-ring-ref = "2833"
+ * /local/domain/1/device/vdispl/0/1/req-event-channel = "17"
+ * /local/domain/1/device/vdispl/0/1/evt-ring-ref = "388"
+ * /local/domain/1/device/vdispl/0/1/evt-event-channel = "18"
+ *
+ ******************************************************************************
+ *                            Backend XenBus Nodes
+ ******************************************************************************
+ *
+ *----------------------------- Protocol version ------------------------------
+ *
+ * versions
+ *      Values:         <string>
+ *
+ *      List of XENDISPL_LIST_SEPARATOR separated protocol versions supported
+ *      by the backend. For example "1,2,3".
+ *
+ ******************************************************************************
+ *                            Frontend XenBus Nodes
+ ******************************************************************************
+ *
+ *-------------------------------- Addressing ---------------------------------
+ *
+ * dom-id
+ *      Values:         <uint16_t>
+ *
+ *      Domain identifier.
+ *
+ * dev-id
+ *      Values:         <uint16_t>
+ *
+ *      Device identifier.
+ *
+ * conn-idx
+ *      Values:         <uint8_t>
+ *
+ *      Zero based contigous index of the connector.
+ *      /local/domain/<dom-id>/device/vdispl/<dev-id>/<conn-idx>/...
+ *
+ *----------------------------- Protocol version ------------------------------
+ *
+ * version
+ *      Values:         <string>
+ *
+ *      Protocol version, chosen among the ones supported by the backend.
+ *
+ *------------------------- Backend buffer allocation -------------------------
+ *
+ * be-alloc
+ *      Values:         "0", "1"
+ *
+ *      If value is set to "1", then backend can be a buffer provider/allocator
+ *      for this domain during XENDISPL_OP_DBUF_CREATE operation (see below
+ *      for negotiation).
+ *      If value is not "1" or omitted frontend must allocate buffers itself.
+ *
+ *----------------------------- Connector settings ----------------------------
+ *
+ * resolution
+ *      Values:         <width, uint32_t>x<height, uint32_t>
+ *
+ *      Width and height of the connector in pixels separated by
+ *      XENDISPL_RESOLUTION_SEPARATOR. This defines visible area of the
+ *      display.
+ *
+ *------------------ Connector Request Transport Parameters -------------------
+ *
+ * This communication path is used to deliver requests from frontend to backend
+ * and get the corresponding responses from backend to frontend,
+ * set up per connector.
+ *
+ * req-event-channel
+ *      Values:         <uint32_t>
+ *
+ *      The identifier of the Xen connector's control event channel
+ *      used to signal activity in the ring buffer.
+ *
+ * req-ring-ref
+ *      Values:         <uint32_t>
+ *
+ *      The Xen grant reference granting permission for the backend to map
+ *      a sole page of connector's control ring buffer.
+ *
+ *------------------- Connector Event Transport Parameters --------------------
+ *
+ * This communication path is used to deliver asynchronous events from backend
+ * to frontend, set up per connector.
+ *
+ * evt-event-channel
+ *      Values:         <uint32_t>
+ *
+ *      The identifier of the Xen connector's event channel
+ *      used to signal activity in the ring buffer.
+ *
+ * evt-ring-ref
+ *      Values:         <uint32_t>
+ *
+ *      The Xen grant reference granting permission for the backend to map
+ *      a sole page of connector's event ring buffer.
+ */
+
+/*
+ ******************************************************************************
+ *                               STATE DIAGRAMS
+ ******************************************************************************
+ *
+ * Tool stack creates front and back state nodes with initial state
+ * XenbusStateInitialising.
+ * Tool stack creates and sets up frontend display configuration
+ * nodes per domain.
+ *
+ *-------------------------------- Normal flow --------------------------------
+ *
+ * Front                                Back
+ * =================================    =====================================
+ * XenbusStateInitialising              XenbusStateInitialising
+ *                                       o Query backend device identification
+ *                                         data.
+ *                                       o Open and validate backend device.
+ *                                                |
+ *                                                |
+ *                                                V
+ *                                      XenbusStateInitWait
+ *
+ * o Query frontend configuration
+ * o Allocate and initialize
+ *   event channels per configured
+ *   connector.
+ * o Publish transport parameters
+ *   that will be in effect during
+ *   this connection.
+ *              |
+ *              |
+ *              V
+ * XenbusStateInitialised
+ *
+ *                                       o Query frontend transport parameters.
+ *                                       o Connect to the event channels.
+ *                                                |
+ *                                                |
+ *                                                V
+ *                                      XenbusStateConnected
+ *
+ *  o Create and initialize OS
+ *    virtual display connectors
+ *    as per configuration.
+ *              |
+ *              |
+ *              V
+ * XenbusStateConnected
+ *
+ *                                      XenbusStateUnknown
+ *                                      XenbusStateClosed
+ *                                      XenbusStateClosing
+ * o Remove virtual display device
+ * o Remove event channels
+ *              |
+ *              |
+ *              V
+ * XenbusStateClosed
+ *
+ *------------------------------- Recovery flow -------------------------------
+ *
+ * In case of frontend unrecoverable errors backend handles that as
+ * if frontend goes into the XenbusStateClosed state.
+ *
+ * In case of backend unrecoverable errors frontend tries removing
+ * the virtualized device. If this is possible at the moment of error,
+ * then frontend goes into the XenbusStateInitialising state and is ready for
+ * new connection with backend. If the virtualized device is still in use and
+ * cannot be removed, then frontend goes into the XenbusStateReconfiguring state
+ * until either the virtualized device is removed or backend initiates a new
+ * connection. On the virtualized device removal frontend goes into the
+ * XenbusStateInitialising state.
+ *
+ * Note on XenbusStateReconfiguring state of the frontend: if backend has
+ * unrecoverable errors then frontend cannot send requests to the backend
+ * and thus cannot provide functionality of the virtualized device anymore.
+ * After backend is back to normal the virtualized device may still hold some
+ * state: configuration in use, allocated buffers, client application state etc.
+ * In most cases, this will require frontend to implement complex recovery
+ * reconnect logic. Instead, by going into XenbusStateReconfiguring state,
+ * frontend will make sure no new clients of the virtualized device are
+ * accepted, allow existing client(s) to exit gracefully by signaling error
+ * state etc.
+ * Once all the clients are gone frontend can reinitialize the virtualized
+ * device and get into XenbusStateInitialising state again signaling the
+ * backend that a new connection can be made.
+ *
+ * There are multiple conditions possible under which frontend will go from
+ * XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS
+ * specific. For example:
+ * 1. The underlying OS framework may provide callbacks to signal that the last
+ *    client of the virtualized device has gone and the device can be removed
+ * 2. Frontend can schedule a deferred work (timer/tasklet/workqueue)
+ *    to periodically check if this is the right time to re-try removal of
+ *    the virtualized device.
+ * 3. By any other means.
+ *
+ ******************************************************************************
+ *                             REQUEST CODES
+ ******************************************************************************
+ * Request codes [0; 15] are reserved and must not be used
+ */
+
+#define XENDISPL_OP_DBUF_CREATE		0x10
+#define XENDISPL_OP_DBUF_DESTROY	0x11
+#define XENDISPL_OP_FB_ATTACH		0x12
+#define XENDISPL_OP_FB_DETACH		0x13
+#define XENDISPL_OP_SET_CONFIG		0x14
+#define XENDISPL_OP_PG_FLIP		0x15
+
+/*
+ ******************************************************************************
+ *                                 EVENT CODES
+ ******************************************************************************
+ */
+#define XENDISPL_EVT_PG_FLIP		0x00
+
+/*
+ ******************************************************************************
+ *               XENSTORE FIELD AND PATH NAME STRINGS, HELPERS
+ ******************************************************************************
+ */
+#define XENDISPL_DRIVER_NAME		"vdispl"
+
+#define XENDISPL_LIST_SEPARATOR		","
+#define XENDISPL_RESOLUTION_SEPARATOR	"x"
+
+#define XENDISPL_FIELD_BE_VERSIONS	"versions"
+#define XENDISPL_FIELD_FE_VERSION	"version"
+#define XENDISPL_FIELD_REQ_RING_REF	"req-ring-ref"
+#define XENDISPL_FIELD_REQ_CHANNEL	"req-event-channel"
+#define XENDISPL_FIELD_EVT_RING_REF	"evt-ring-ref"
+#define XENDISPL_FIELD_EVT_CHANNEL	"evt-event-channel"
+#define XENDISPL_FIELD_RESOLUTION	"resolution"
+#define XENDISPL_FIELD_BE_ALLOC		"be-alloc"
+
+/*
+ ******************************************************************************
+ *                          STATUS RETURN CODES
+ ******************************************************************************
+ *
+ * Status return code is zero on success and -XEN_EXX on failure.
+ *
+ ******************************************************************************
+ *                              Assumptions
+ ******************************************************************************
+ * o usage of grant reference 0 as invalid grant reference:
+ *   grant reference 0 is valid, but never exposed to a PV driver,
+ *   because of the fact it is already in use/reserved by the PV console.
+ * o all references in this document to page sizes must be treated
+ *   as pages of size XEN_PAGE_SIZE unless otherwise noted.
+ *
+ ******************************************************************************
+ *       Description of the protocol between frontend and backend driver
+ ******************************************************************************
+ *
+ * The two halves of a Para-virtual display driver communicate with
+ * each other using shared pages and event channels.
+ * Shared page contains a ring with request/response packets.
+ *
+ * All reserved fields in the structures below must be 0.
+ * Display buffers's cookie of value 0 is treated as invalid.
+ * Framebuffer's cookie of value 0 is treated as invalid.
+ *
+ * For all request/response/event packets that use cookies:
+ *   dbuf_cookie - uint64_t, unique to guest domain value used by the backend
+ *     to map remote display buffer to its local one
+ *   fb_cookie - uint64_t, unique to guest domain value used by the backend
+ *     to map remote framebuffer to its local one
+ *
+ *---------------------------------- Requests ---------------------------------
+ *
+ * All requests/responses, which are not connector specific, must be sent over
+ * control ring of the connector which has the index value of 0:
+ *   /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
+ *
+ * All request packets have the same length (64 octets)
+ * All request packets have common header:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |    operation   |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ *   id - uint16_t, private guest value, echoed in response
+ *   operation - uint8_t, operation code, XENDISPL_OP_???
+ *
+ * Request dbuf creation - request creation of a display buffer.
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |_OP_DBUF_CREATE |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                       dbuf_cookie low 32-bit                      | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                       dbuf_cookie high 32-bit                     | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                               width                               | 20
+ * +----------------+----------------+----------------+----------------+
+ * |                               height                              | 24
+ * +----------------+----------------+----------------+----------------+
+ * |                                bpp                                | 28
+ * +----------------+----------------+----------------+----------------+
+ * |                             buffer_sz                             | 32
+ * +----------------+----------------+----------------+----------------+
+ * |                               flags                               | 36
+ * +----------------+----------------+----------------+----------------+
+ * |                           gref_directory                          | 40
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 44
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Must be sent over control ring of the connector which has the index
+ * value of 0:
+ *   /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
+ * All unused bits in flags field must be set to 0.
+ *
+ * An attempt to create multiple display buffers with the same dbuf_cookie is
+ * an error. dbuf_cookie can be re-used after destroying the corresponding
+ * display buffer.
+ *
+ * Width and height of the display buffers can be smaller, equal or bigger
+ * than the connector's resolution. Depth/pixel format of the individual
+ * buffers can differ as well.
+ *
+ * width - uint32_t, width in pixels
+ * height - uint32_t, height in pixels
+ * bpp - uint32_t, bits per pixel
+ * buffer_sz - uint32_t, buffer size to be allocated, octets
+ * flags - uint32_t, flags of the operation
+ *   o XENDISPL_DBUF_FLG_REQ_ALLOC - if set, then backend is requested
+ *     to allocate the buffer with the parameters provided in this request.
+ *     Page directory is handled as follows:
+ *       Frontend on request:
+ *         o allocates pages for the directory (gref_directory,
+ *           gref_dir_next_page(s)
+ *         o grants permissions for the pages of the directory to the backend
+ *         o sets gref_dir_next_page fields
+ *       Backend on response:
+ *         o grants permissions for the pages of the buffer allocated to
+ *           the frontend
+ *         o fills in page directory with grant references
+ *           (gref[] in struct xendispl_page_directory)
+ * gref_directory - grant_ref_t, a reference to the first shared page
+ *   describing shared buffer references. At least one page exists. If shared
+ *   buffer size (buffer_sz) exceeds what can be addressed by this single page,
+ *   then reference to the next page must be supplied (see gref_dir_next_page
+ *   below)
+ */
+
+#define XENDISPL_DBUF_FLG_REQ_ALLOC	(1 << 0)
+
+struct xendispl_dbuf_create_req {
+	uint64_t dbuf_cookie;
+	uint32_t width;
+	uint32_t height;
+	uint32_t bpp;
+	uint32_t buffer_sz;
+	uint32_t flags;
+	grant_ref_t gref_directory;
+};
+
+/*
+ * Shared page for XENDISPL_OP_DBUF_CREATE buffer descriptor (gref_directory in
+ * the request) employs a list of pages, describing all pages of the shared
+ * data buffer:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |                        gref_dir_next_page                         | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                              gref[0]                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                              gref[i]                              | i*4+8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             gref[N - 1]                           | N*4+8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * gref_dir_next_page - grant_ref_t, reference to the next page describing
+ *   page directory. Must be 0 if there are no more pages in the list.
+ * gref[i] - grant_ref_t, reference to a shared page of the buffer
+ *   allocated at XENDISPL_OP_DBUF_CREATE
+ *
+ * Number of grant_ref_t entries in the whole page directory is not
+ * passed, but instead can be calculated as:
+ *   num_grefs_total = (XENDISPL_OP_DBUF_CREATE.buffer_sz + XEN_PAGE_SIZE - 1) /
+ *       XEN_PAGE_SIZE
+ */
+
+struct xendispl_page_directory {
+	grant_ref_t gref_dir_next_page;
+	grant_ref_t gref[1]; /* Variable length */
+};
+
+/*
+ * Request dbuf destruction - destroy a previously allocated display buffer:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |_OP_DBUF_DESTROY|   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                       dbuf_cookie low 32-bit                      | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                       dbuf_cookie high 32-bit                     | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Must be sent over control ring of the connector which has the index
+ * value of 0:
+ *   /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
+ */
+
+struct xendispl_dbuf_destroy_req {
+	uint64_t dbuf_cookie;
+};
+
+/*
+ * Request framebuffer attachment - request attachment of a framebuffer to
+ * previously created display buffer.
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                | _OP_FB_ATTACH  |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                       dbuf_cookie low 32-bit                      | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                       dbuf_cookie high 32-bit                     | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie low 32-bit                       | 20
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie high 32-bit                      | 24
+ * +----------------+----------------+----------------+----------------+
+ * |                               width                               | 28
+ * +----------------+----------------+----------------+----------------+
+ * |                               height                              | 32
+ * +----------------+----------------+----------------+----------------+
+ * |                            pixel_format                           | 36
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Must be sent over control ring of the connector which has the index
+ * value of 0:
+ *   /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
+ * Width and height can be smaller, equal or bigger than the connector's
+ * resolution.
+ *
+ * An attempt to create multiple frame buffers with the same fb_cookie is
+ * an error. fb_cookie can be re-used after destroying the corresponding
+ * frame buffer.
+ *
+ * width - uint32_t, width in pixels
+ * height - uint32_t, height in pixels
+ * pixel_format - uint32_t, pixel format of the framebuffer, FOURCC code
+ */
+
+struct xendispl_fb_attach_req {
+	uint64_t dbuf_cookie;
+	uint64_t fb_cookie;
+	uint32_t width;
+	uint32_t height;
+	uint32_t pixel_format;
+};
+
+/*
+ * Request framebuffer detach - detach a previously
+ * attached framebuffer from the display buffer in request:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |  _OP_FB_DETACH |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie low 32-bit                       | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie high 32-bit                      | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Must be sent over control ring of the connector which has the index
+ * value of 0:
+ *   /local/domain/<dom-id>/device/vdispl/<dev-id>/0/req-ring-ref
+ */
+
+struct xendispl_fb_detach_req {
+	uint64_t fb_cookie;
+};
+
+/*
+ * Request configuration set/reset - request to set or reset
+ * the configuration/mode of the display:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                | _OP_SET_CONFIG |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie low 32-bit                       | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie high 32-bit                      | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                                 x                                 | 20
+ * +----------------+----------------+----------------+----------------+
+ * |                                 y                                 | 24
+ * +----------------+----------------+----------------+----------------+
+ * |                               width                               | 28
+ * +----------------+----------------+----------------+----------------+
+ * |                               height                              | 32
+ * +----------------+----------------+----------------+----------------+
+ * |                                bpp                                | 40
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 44
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Pass all zeros to reset, otherwise command is treated as
+ * configuration set.
+ * Framebuffer's cookie defines which framebuffer/dbuf must be
+ * displayed while enabling display (applying configuration).
+ * x, y, width and height are bound by the connector's resolution and must not
+ * exceed it.
+ *
+ * x - uint32_t, starting position in pixels by X axis
+ * y - uint32_t, starting position in pixels by Y axis
+ * width - uint32_t, width in pixels
+ * height - uint32_t, height in pixels
+ * bpp - uint32_t, bits per pixel
+ */
+
+struct xendispl_set_config_req {
+	uint64_t fb_cookie;
+	uint32_t x;
+	uint32_t y;
+	uint32_t width;
+	uint32_t height;
+	uint32_t bpp;
+};
+
+/*
+ * Request page flip - request to flip a page identified by the framebuffer
+ * cookie:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                | _OP_PG_FLIP    |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie low 32-bit                       | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie high 32-bit                      | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ */
+
+struct xendispl_page_flip_req {
+	uint64_t fb_cookie;
+};
+
+/*
+ *---------------------------------- Responses --------------------------------
+ *
+ * All response packets have the same length (64 octets)
+ *
+ * All response packets have common header:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |            reserved             | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                              status                               | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 12
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ *
+ * id - uint16_t, private guest value, echoed from request
+ * status - int32_t, response status, zero on success and -XEN_EXX on failure
+ *
+ *----------------------------------- Events ----------------------------------
+ *
+ * Events are sent via a shared page allocated by the front and propagated by
+ *   evt-event-channel/evt-ring-ref XenStore entries
+ * All event packets have the same length (64 octets)
+ * All event packets have common header:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |      type      |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * id - uint16_t, event id, may be used by front
+ * type - uint8_t, type of the event
+ *
+ *
+ * Page flip complete event - event from back to front on page flip completed:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |   _EVT_PG_FLIP |   reserved     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie low 32-bit                       | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                        fb_cookie high 32-bit                      | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 64
+ * +----------------+----------------+----------------+----------------+
+ */
+
+struct xendispl_pg_flip_evt {
+	uint64_t fb_cookie;
+};
+
+struct xendispl_req {
+	uint16_t id;
+	uint8_t operation;
+	uint8_t reserved[5];
+	union {
+		struct xendispl_dbuf_create_req dbuf_create;
+		struct xendispl_dbuf_destroy_req dbuf_destroy;
+		struct xendispl_fb_attach_req fb_attach;
+		struct xendispl_fb_detach_req fb_detach;
+		struct xendispl_set_config_req set_config;
+		struct xendispl_page_flip_req pg_flip;
+		uint8_t reserved[56];
+	} op;
+};
+
+struct xendispl_resp {
+	uint16_t id;
+	uint8_t operation;
+	uint8_t reserved;
+	int32_t status;
+	uint8_t reserved1[56];
+};
+
+struct xendispl_evt {
+	uint16_t id;
+	uint8_t type;
+	uint8_t reserved[5];
+	union {
+		struct xendispl_pg_flip_evt pg_flip;
+		uint8_t reserved[56];
+	} op;
+};
+
+DEFINE_RING_TYPES(xen_displif, struct xendispl_req, struct xendispl_resp);
+
+/*
+ ******************************************************************************
+ *                        Back to front events delivery
+ ******************************************************************************
+ * In order to deliver asynchronous events from back to front a shared page is
+ * allocated by front and its granted reference propagated to back via
+ * XenStore entries (evt-ring-ref/evt-event-channel).
+ * This page has a common header used by both front and back to synchronize
+ * access and control event's ring buffer, while back being a producer of the
+ * events and front being a consumer. The rest of the page after the header
+ * is used for event packets.
+ *
+ * Upon reception of an event(s) front may confirm its reception
+ * for either each event, group of events or none.
+ */
+
+struct xendispl_event_page {
+	uint32_t in_cons;
+	uint32_t in_prod;
+	uint8_t reserved[56];
+};
+
+#define XENDISPL_EVENT_PAGE_SIZE XEN_PAGE_SIZE
+#define XENDISPL_IN_RING_OFFS (sizeof(struct xendispl_event_page))
+#define XENDISPL_IN_RING_SIZE (XENDISPL_EVENT_PAGE_SIZE - XENDISPL_IN_RING_OFFS)
+#define XENDISPL_IN_RING_LEN (XENDISPL_IN_RING_SIZE / sizeof(struct xendispl_evt))
+#define XENDISPL_IN_RING(page) \
+	((struct xendispl_evt *)((char *)(page) + XENDISPL_IN_RING_OFFS))
+#define XENDISPL_IN_RING_REF(page, idx) \
+	(XENDISPL_IN_RING((page))[(idx) % XENDISPL_IN_RING_LEN])
+
+#endif /* __XEN_PUBLIC_IO_DISPLIF_H__ */
diff --git a/include/xen/interface/io/kbdif.h b/include/xen/interface/io/kbdif.h
index 8066c7849fbe..2a9510ade701 100644
--- a/include/xen/interface/io/kbdif.h
+++ b/include/xen/interface/io/kbdif.h
@@ -26,43 +26,432 @@
 #ifndef __XEN_PUBLIC_IO_KBDIF_H__
 #define __XEN_PUBLIC_IO_KBDIF_H__
 
-/* In events (backend -> frontend) */
+/*
+ *****************************************************************************
+ *                     Feature and Parameter Negotiation
+ *****************************************************************************
+ *
+ * The two halves of a para-virtual driver utilize nodes within
+ * XenStore to communicate capabilities and to negotiate operating parameters.
+ * This section enumerates these nodes which reside in the respective front and
+ * backend portions of XenStore, following XenBus convention.
+ *
+ * All data in XenStore is stored as strings.  Nodes specifying numeric
+ * values are encoded in decimal. Integer value ranges listed below are
+ * expressed as fixed sized integer types capable of storing the conversion
+ * of a properly formated node string, without loss of information.
+ *
+ *****************************************************************************
+ *                            Backend XenBus Nodes
+ *****************************************************************************
+ *
+ *---------------------------- Features supported ----------------------------
+ *
+ * Capable backend advertises supported features by publishing
+ * corresponding entries in XenStore and puts 1 as the value of the entry.
+ * If a feature is not supported then 0 must be set or feature entry omitted.
+ *
+ * feature-abs-pointer
+ *      Values:         <uint>
+ *
+ *      Backends, which support reporting of absolute coordinates for pointer
+ *      device should set this to 1.
+ *
+ * feature-multi-touch
+ *      Values:         <uint>
+ *
+ *      Backends, which support reporting of multi-touch events
+ *      should set this to 1.
+ *
+ *------------------------- Pointer Device Parameters ------------------------
+ *
+ * width
+ *      Values:         <uint>
+ *
+ *      Maximum X coordinate (width) to be used by the frontend
+ *      while reporting input events, pixels, [0; UINT32_MAX].
+ *
+ * height
+ *      Values:         <uint>
+ *
+ *      Maximum Y coordinate (height) to be used by the frontend
+ *      while reporting input events, pixels, [0; UINT32_MAX].
+ *
+ *****************************************************************************
+ *                            Frontend XenBus Nodes
+ *****************************************************************************
+ *
+ *------------------------------ Feature request -----------------------------
+ *
+ * Capable frontend requests features from backend via setting corresponding
+ * entries to 1 in XenStore. Requests for features not advertised as supported
+ * by the backend have no effect.
+ *
+ * request-abs-pointer
+ *      Values:         <uint>
+ *
+ *      Request backend to report absolute pointer coordinates
+ *      (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
+ *
+ * request-multi-touch
+ *      Values:         <uint>
+ *
+ *      Request backend to report multi-touch events.
+ *
+ *----------------------- Request Transport Parameters -----------------------
+ *
+ * event-channel
+ *      Values:         <uint>
+ *
+ *      The identifier of the Xen event channel used to signal activity
+ *      in the ring buffer.
+ *
+ * page-gref
+ *      Values:         <uint>
+ *
+ *      The Xen grant reference granting permission for the backend to map
+ *      a sole page in a single page sized event ring buffer.
+ *
+ * page-ref
+ *      Values:         <uint>
+ *
+ *      OBSOLETE, not recommended for use.
+ *      PFN of the shared page.
+ *
+ *----------------------- Multi-touch Device Parameters -----------------------
+ *
+ * multi-touch-num-contacts
+ *      Values:         <uint>
+ *
+ *      Number of simultaneous touches reported.
+ *
+ * multi-touch-width
+ *      Values:         <uint>
+ *
+ *      Width of the touch area to be used by the frontend
+ *      while reporting input events, pixels, [0; UINT32_MAX].
+ *
+ * multi-touch-height
+ *      Values:         <uint>
+ *
+ *      Height of the touch area to be used by the frontend
+ *      while reporting input events, pixels, [0; UINT32_MAX].
+ */
 
 /*
- * Frontends should ignore unknown in events.
+ * EVENT CODES.
  */
 
-/* Pointer movement event */
-#define XENKBD_TYPE_MOTION  1
-/* Event type 2 currently not used */
-/* Key event (includes pointer buttons) */
-#define XENKBD_TYPE_KEY     3
+#define XENKBD_TYPE_MOTION		1
+#define XENKBD_TYPE_RESERVED		2
+#define XENKBD_TYPE_KEY			3
+#define XENKBD_TYPE_POS			4
+#define XENKBD_TYPE_MTOUCH		5
+
+/* Multi-touch event sub-codes */
+
+#define XENKBD_MT_EV_DOWN		0
+#define XENKBD_MT_EV_UP			1
+#define XENKBD_MT_EV_MOTION		2
+#define XENKBD_MT_EV_SYN		3
+#define XENKBD_MT_EV_SHAPE		4
+#define XENKBD_MT_EV_ORIENT		5
+
+/*
+ * CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
+ */
+
+#define XENKBD_DRIVER_NAME		"vkbd"
+
+#define XENKBD_FIELD_FEAT_ABS_POINTER	"feature-abs-pointer"
+#define XENKBD_FIELD_FEAT_MTOUCH	"feature-multi-touch"
+#define XENKBD_FIELD_REQ_ABS_POINTER	"request-abs-pointer"
+#define XENKBD_FIELD_REQ_MTOUCH		"request-multi-touch"
+#define XENKBD_FIELD_RING_GREF		"page-gref"
+#define XENKBD_FIELD_EVT_CHANNEL	"event-channel"
+#define XENKBD_FIELD_WIDTH		"width"
+#define XENKBD_FIELD_HEIGHT		"height"
+#define XENKBD_FIELD_MT_WIDTH		"multi-touch-width"
+#define XENKBD_FIELD_MT_HEIGHT		"multi-touch-height"
+#define XENKBD_FIELD_MT_NUM_CONTACTS	"multi-touch-num-contacts"
+
+/* OBSOLETE, not recommended for use */
+#define XENKBD_FIELD_RING_REF		"page-ref"
+
 /*
- * Pointer position event
- * Capable backend sets feature-abs-pointer in xenstore.
- * Frontend requests ot instead of XENKBD_TYPE_MOTION by setting
- * request-abs-update in xenstore.
+ *****************************************************************************
+ * Description of the protocol between frontend and backend driver.
+ *****************************************************************************
+ *
+ * The two halves of a Para-virtual driver communicate with
+ * each other using a shared page and an event channel.
+ * Shared page contains a ring with event structures.
+ *
+ * All reserved fields in the structures below must be 0.
+ *
+ *****************************************************************************
+ *                           Backend to frontend events
+ *****************************************************************************
+ *
+ * Frontends should ignore unknown in events.
+ * All event packets have the same length (40 octets)
+ * All event packets have common header:
+ *
+ *          0         octet
+ * +-----------------+
+ * |       type      |
+ * +-----------------+
+ * type - uint8_t, event code, XENKBD_TYPE_???
+ *
+ *
+ * Pointer relative movement event
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MOTION  |                     reserved                     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                               rel_x                               | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                               rel_y                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                               rel_z                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * rel_x - int32_t, relative X motion
+ * rel_y - int32_t, relative Y motion
+ * rel_z - int32_t, relative Z motion (wheel)
  */
-#define XENKBD_TYPE_POS     4
 
 struct xenkbd_motion {
-	uint8_t type;		/* XENKBD_TYPE_MOTION */
-	int32_t rel_x;		/* relative X motion */
-	int32_t rel_y;		/* relative Y motion */
-	int32_t rel_z;		/* relative Z motion (wheel) */
+	uint8_t type;
+	int32_t rel_x;
+	int32_t rel_y;
+	int32_t rel_z;
 };
 
+/*
+ * Key event (includes pointer buttons)
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_KEY     |     pressed    |            reserved             | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                              keycode                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 12
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * pressed - uint8_t, 1 if pressed; 0 otherwise
+ * keycode - uint32_t, KEY_* from linux/input.h
+ */
+
 struct xenkbd_key {
-	uint8_t type;		/* XENKBD_TYPE_KEY */
-	uint8_t pressed;	/* 1 if pressed; 0 otherwise */
-	uint32_t keycode;	/* KEY_* from linux/input.h */
+	uint8_t type;
+	uint8_t pressed;
+	uint32_t keycode;
 };
 
+/*
+ * Pointer absolute position event
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_POS     |                     reserved                     | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                               abs_x                               | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                               abs_y                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                               rel_z                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * abs_x - int32_t, absolute X position (in FB pixels)
+ * abs_y - int32_t, absolute Y position (in FB pixels)
+ * rel_z - int32_t, relative Z motion (wheel)
+ */
+
 struct xenkbd_position {
-	uint8_t type;		/* XENKBD_TYPE_POS */
-	int32_t abs_x;		/* absolute X position (in FB pixels) */
-	int32_t abs_y;		/* absolute Y position (in FB pixels) */
-	int32_t rel_z;		/* relative Z motion (wheel) */
+	uint8_t type;
+	int32_t abs_x;
+	int32_t abs_y;
+	int32_t rel_z;
+};
+
+/*
+ * Multi-touch event and its sub-types
+ *
+ * All multi-touch event packets have common header:
+ *
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |   event_type   |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
+ * contact_id - unt8_t, ID of the contact
+ *
+ * Touch interactions can consist of one or more contacts.
+ * For each contact, a series of events is generated, starting
+ * with a down event, followed by zero or more motion events,
+ * and ending with an up event. Events relating to the same
+ * contact point can be identified by the ID of the sequence: contact ID.
+ * Contact ID may be reused after XENKBD_MT_EV_UP event and
+ * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
+ *
+ * For further information please refer to documentation on Wayland [1],
+ * Linux [2] and Windows [3] multi-touch support.
+ *
+ * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
+ * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
+ * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
+ *
+ *
+ * Multi-touch down event - sent when a new touch is made: touch is assigned
+ * a unique contact ID, sent with this and consequent events related
+ * to this touch.
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |   _MT_EV_DOWN  |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                               abs_x                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                               abs_y                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * abs_x - int32_t, absolute X position, in pixels
+ * abs_y - int32_t, absolute Y position, in pixels
+ *
+ * Multi-touch contact release event
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |  _MT_EV_UP     |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Multi-touch motion event
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |  _MT_EV_MOTION |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                               abs_x                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                               abs_y                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * abs_x - int32_t, absolute X position, in pixels,
+ * abs_y - int32_t, absolute Y position, in pixels,
+ *
+ * Multi-touch input synchronization event - shows end of a set of events
+ * which logically belong together.
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |  _MT_EV_SYN    |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Multi-touch shape event - touch point's shape has changed its shape.
+ * Shape is approximated by an ellipse through the major and minor axis
+ * lengths: major is the longer diameter of the ellipse and minor is the
+ * shorter one. Center of the ellipse is reported via
+ * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |  _MT_EV_SHAPE  |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                               major                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                               minor                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * major - unt32_t, length of the major axis, pixels
+ * minor - unt32_t, length of the minor axis, pixels
+ *
+ * Multi-touch orientation event - touch point's shape has changed
+ * its orientation: calculated as a clockwise angle between the major axis
+ * of the ellipse and positive Y axis in degrees, [-180; +180].
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |  _TYPE_MTOUCH  |  _MT_EV_ORIENT |   contact_id   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |           orientation           |            reserved             | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 16
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * orientation - int16_t, clockwise angle of the major axis
+ */
+
+struct xenkbd_mtouch {
+	uint8_t type;			/* XENKBD_TYPE_MTOUCH */
+	uint8_t event_type;		/* XENKBD_MT_EV_??? */
+	uint8_t contact_id;
+	uint8_t reserved[5];		/* reserved for the future use */
+	union {
+		struct {
+			int32_t abs_x;	/* absolute X position, pixels */
+			int32_t abs_y;	/* absolute Y position, pixels */
+		} pos;
+		struct {
+			uint32_t major;	/* length of the major axis, pixels */
+			uint32_t minor;	/* length of the minor axis, pixels */
+		} shape;
+		int16_t orientation;	/* clockwise angle of the major axis */
+	} u;
 };
 
 #define XENKBD_IN_EVENT_SIZE 40
@@ -72,15 +461,26 @@ union xenkbd_in_event {
 	struct xenkbd_motion motion;
 	struct xenkbd_key key;
 	struct xenkbd_position pos;
+	struct xenkbd_mtouch mtouch;
 	char pad[XENKBD_IN_EVENT_SIZE];
 };
 
-/* Out events (frontend -> backend) */
-
 /*
+ *****************************************************************************
+ *                            Frontend to backend events
+ *****************************************************************************
+ *
  * Out events may be sent only when requested by backend, and receipt
  * of an unknown out event is an error.
  * No out events currently defined.
+
+ * All event packets have the same length (40 octets)
+ * All event packets have common header:
+ *          0         octet
+ * +-----------------+
+ * |       type      |
+ * +-----------------+
+ * type - uint8_t, event code
  */
 
 #define XENKBD_OUT_EVENT_SIZE 40
@@ -90,7 +490,11 @@ union xenkbd_out_event {
 	char pad[XENKBD_OUT_EVENT_SIZE];
 };
 
-/* shared page */
+/*
+ *****************************************************************************
+ *                            Shared page
+ *****************************************************************************
+ */
 
 #define XENKBD_IN_RING_SIZE 2048
 #define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
@@ -113,4 +517,4 @@ struct xenkbd_page {
 	uint32_t out_cons, out_prod;
 };
 
-#endif
+#endif /* __XEN_PUBLIC_IO_KBDIF_H__ */
diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h
index 21f4fbd55e48..c79456855539 100644
--- a/include/xen/interface/io/ring.h
+++ b/include/xen/interface/io/ring.h
@@ -283,4 +283,147 @@ struct __name##_back_ring {						\
     (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r);			\
 } while (0)
 
+
+/*
+ * DEFINE_XEN_FLEX_RING_AND_INTF defines two monodirectional rings and
+ * functions to check if there is data on the ring, and to read and
+ * write to them.
+ *
+ * DEFINE_XEN_FLEX_RING is similar to DEFINE_XEN_FLEX_RING_AND_INTF, but
+ * does not define the indexes page. As different protocols can have
+ * extensions to the basic format, this macro allow them to define their
+ * own struct.
+ *
+ * XEN_FLEX_RING_SIZE
+ *   Convenience macro to calculate the size of one of the two rings
+ *   from the overall order.
+ *
+ * $NAME_mask
+ *   Function to apply the size mask to an index, to reduce the index
+ *   within the range [0-size].
+ *
+ * $NAME_read_packet
+ *   Function to read data from the ring. The amount of data to read is
+ *   specified by the "size" argument.
+ *
+ * $NAME_write_packet
+ *   Function to write data to the ring. The amount of data to write is
+ *   specified by the "size" argument.
+ *
+ * $NAME_get_ring_ptr
+ *   Convenience function that returns a pointer to read/write to the
+ *   ring at the right location.
+ *
+ * $NAME_data_intf
+ *   Indexes page, shared between frontend and backend. It also
+ *   contains the array of grant refs.
+ *
+ * $NAME_queued
+ *   Function to calculate how many bytes are currently on the ring,
+ *   ready to be read. It can also be used to calculate how much free
+ *   space is currently on the ring (XEN_FLEX_RING_SIZE() -
+ *   $NAME_queued()).
+ */
+
+#ifndef XEN_PAGE_SHIFT
+/* The PAGE_SIZE for ring protocols and hypercall interfaces is always
+ * 4K, regardless of the architecture, and page granularity chosen by
+ * operating systems.
+ */
+#define XEN_PAGE_SHIFT 12
+#endif
+#define XEN_FLEX_RING_SIZE(order)                                             \
+    (1UL << ((order) + XEN_PAGE_SHIFT - 1))
+
+#define DEFINE_XEN_FLEX_RING(name)                                            \
+static inline RING_IDX name##_mask(RING_IDX idx, RING_IDX ring_size)          \
+{                                                                             \
+    return idx & (ring_size - 1);                                             \
+}                                                                             \
+                                                                              \
+static inline unsigned char *name##_get_ring_ptr(unsigned char *buf,          \
+                                                 RING_IDX idx,                \
+                                                 RING_IDX ring_size)          \
+{                                                                             \
+    return buf + name##_mask(idx, ring_size);                                 \
+}                                                                             \
+                                                                              \
+static inline void name##_read_packet(void *opaque,                           \
+                                      const unsigned char *buf,               \
+                                      size_t size,                            \
+                                      RING_IDX masked_prod,                   \
+                                      RING_IDX *masked_cons,                  \
+                                      RING_IDX ring_size)                     \
+{                                                                             \
+    if (*masked_cons < masked_prod ||                                         \
+        size <= ring_size - *masked_cons) {                                   \
+        memcpy(opaque, buf + *masked_cons, size);                             \
+    } else {                                                                  \
+        memcpy(opaque, buf + *masked_cons, ring_size - *masked_cons);         \
+        memcpy((unsigned char *)opaque + ring_size - *masked_cons, buf,       \
+               size - (ring_size - *masked_cons));                            \
+    }                                                                         \
+    *masked_cons = name##_mask(*masked_cons + size, ring_size);               \
+}                                                                             \
+                                                                              \
+static inline void name##_write_packet(unsigned char *buf,                    \
+                                       const void *opaque,                    \
+                                       size_t size,                           \
+                                       RING_IDX *masked_prod,                 \
+                                       RING_IDX masked_cons,                  \
+                                       RING_IDX ring_size)                    \
+{                                                                             \
+    if (*masked_prod < masked_cons ||                                         \
+        size <= ring_size - *masked_prod) {                                   \
+        memcpy(buf + *masked_prod, opaque, size);                             \
+    } else {                                                                  \
+        memcpy(buf + *masked_prod, opaque, ring_size - *masked_prod);         \
+        memcpy(buf, (unsigned char *)opaque + (ring_size - *masked_prod),     \
+               size - (ring_size - *masked_prod));                            \
+    }                                                                         \
+    *masked_prod = name##_mask(*masked_prod + size, ring_size);               \
+}                                                                             \
+                                                                              \
+static inline RING_IDX name##_queued(RING_IDX prod,                           \
+                                     RING_IDX cons,                           \
+                                     RING_IDX ring_size)                      \
+{                                                                             \
+    RING_IDX size;                                                            \
+                                                                              \
+    if (prod == cons)                                                         \
+        return 0;                                                             \
+                                                                              \
+    prod = name##_mask(prod, ring_size);                                      \
+    cons = name##_mask(cons, ring_size);                                      \
+                                                                              \
+    if (prod == cons)                                                         \
+        return ring_size;                                                     \
+                                                                              \
+    if (prod > cons)                                                          \
+        size = prod - cons;                                                   \
+    else                                                                      \
+        size = ring_size - (cons - prod);                                     \
+    return size;                                                              \
+}                                                                             \
+                                                                              \
+struct name##_data {                                                          \
+    unsigned char *in; /* half of the allocation */                           \
+    unsigned char *out; /* half of the allocation */                          \
+}
+
+#define DEFINE_XEN_FLEX_RING_AND_INTF(name)                                   \
+struct name##_data_intf {                                                     \
+    RING_IDX in_cons, in_prod;                                                \
+                                                                              \
+    uint8_t pad1[56];                                                         \
+                                                                              \
+    RING_IDX out_cons, out_prod;                                              \
+                                                                              \
+    uint8_t pad2[56];                                                         \
+                                                                              \
+    RING_IDX ring_order;                                                      \
+    grant_ref_t ref[];                                                        \
+};                                                                            \
+DEFINE_XEN_FLEX_RING(name)
+
 #endif /* __XEN_PUBLIC_IO_RING_H__ */
diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h
new file mode 100644
index 000000000000..5c918276835e
--- /dev/null
+++ b/include/xen/interface/io/sndif.h
@@ -0,0 +1,793 @@
+/******************************************************************************
+ * sndif.h
+ *
+ * Unified sound-device I/O interface for Xen guest OSes.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Copyright (C) 2013-2015 GlobalLogic Inc.
+ * Copyright (C) 2016-2017 EPAM Systems Inc.
+ *
+ * Authors: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
+ *          Oleksandr Grytsov <oleksandr_grytsov@epam.com>
+ *          Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com>
+ *          Iurii Konovalenko <iurii.konovalenko@globallogic.com>
+ */
+
+#ifndef __XEN_PUBLIC_IO_SNDIF_H__
+#define __XEN_PUBLIC_IO_SNDIF_H__
+
+#include "ring.h"
+#include "../grant_table.h"
+
+/*
+ ******************************************************************************
+ *                  Feature and Parameter Negotiation
+ ******************************************************************************
+ *
+ * Front->back notifications: when enqueuing a new request, sending a
+ * notification can be made conditional on xensnd_req (i.e., the generic
+ * hold-off mechanism provided by the ring macros). Backends must set
+ * xensnd_req appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()).
+ *
+ * Back->front notifications: when enqueuing a new response, sending a
+ * notification can be made conditional on xensnd_resp (i.e., the generic
+ * hold-off mechanism provided by the ring macros). Frontends must set
+ * xensnd_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()).
+ *
+ * The two halves of a para-virtual sound card driver utilize nodes within
+ * XenStore to communicate capabilities and to negotiate operating parameters.
+ * This section enumerates these nodes which reside in the respective front and
+ * backend portions of XenStore, following the XenBus convention.
+ *
+ * All data in XenStore is stored as strings. Nodes specifying numeric
+ * values are encoded in decimal. Integer value ranges listed below are
+ * expressed as fixed sized integer types capable of storing the conversion
+ * of a properly formated node string, without loss of information.
+ *
+ ******************************************************************************
+ *                        Example configuration
+ ******************************************************************************
+ *
+ * Note: depending on the use-case backend can expose more sound cards and
+ * PCM devices/streams than the underlying HW physically has by employing
+ * SW mixers, configuring virtual sound streams, channels etc.
+ *
+ * This is an example of backend and frontend configuration:
+ *
+ *--------------------------------- Backend -----------------------------------
+ *
+ * /local/domain/0/backend/vsnd/1/0/frontend-id = "1"
+ * /local/domain/0/backend/vsnd/1/0/frontend = "/local/domain/1/device/vsnd/0"
+ * /local/domain/0/backend/vsnd/1/0/state = "4"
+ * /local/domain/0/backend/vsnd/1/0/versions = "1,2"
+ *
+ *--------------------------------- Frontend ----------------------------------
+ *
+ * /local/domain/1/device/vsnd/0/backend-id = "0"
+ * /local/domain/1/device/vsnd/0/backend = "/local/domain/0/backend/vsnd/1/0"
+ * /local/domain/1/device/vsnd/0/state = "4"
+ * /local/domain/1/device/vsnd/0/version = "1"
+ *
+ *----------------------------- Card configuration ----------------------------
+ *
+ * /local/domain/1/device/vsnd/0/short-name = "Card short name"
+ * /local/domain/1/device/vsnd/0/long-name = "Card long name"
+ * /local/domain/1/device/vsnd/0/sample-rates = "8000,32000,44100,48000,96000"
+ * /local/domain/1/device/vsnd/0/sample-formats = "s8,u8,s16_le,s16_be"
+ * /local/domain/1/device/vsnd/0/buffer-size = "262144"
+ *
+ *------------------------------- PCM device 0 --------------------------------
+ *
+ * /local/domain/1/device/vsnd/0/0/name = "General analog"
+ * /local/domain/1/device/vsnd/0/0/channels-max = "5"
+ *
+ *----------------------------- Stream 0, playback ----------------------------
+ *
+ * /local/domain/1/device/vsnd/0/0/0/type = "p"
+ * /local/domain/1/device/vsnd/0/0/0/sample-formats = "s8,u8"
+ * /local/domain/1/device/vsnd/0/0/0/unique-id = "0"
+ *
+ * /local/domain/1/device/vsnd/0/0/0/ring-ref = "386"
+ * /local/domain/1/device/vsnd/0/0/0/event-channel = "15"
+ *
+ *------------------------------ Stream 1, capture ----------------------------
+ *
+ * /local/domain/1/device/vsnd/0/0/1/type = "c"
+ * /local/domain/1/device/vsnd/0/0/1/channels-max = "2"
+ * /local/domain/1/device/vsnd/0/0/1/unique-id = "1"
+ *
+ * /local/domain/1/device/vsnd/0/0/1/ring-ref = "384"
+ * /local/domain/1/device/vsnd/0/0/1/event-channel = "13"
+ *
+ *------------------------------- PCM device 1 --------------------------------
+ *
+ * /local/domain/1/device/vsnd/0/1/name = "HDMI-0"
+ * /local/domain/1/device/vsnd/0/1/sample-rates = "8000,32000,44100"
+ *
+ *------------------------------ Stream 0, capture ----------------------------
+ *
+ * /local/domain/1/device/vsnd/0/1/0/type = "c"
+ * /local/domain/1/device/vsnd/0/1/0/unique-id = "2"
+ *
+ * /local/domain/1/device/vsnd/0/1/0/ring-ref = "387"
+ * /local/domain/1/device/vsnd/0/1/0/event-channel = "151"
+ *
+ *------------------------------- PCM device 2 --------------------------------
+ *
+ * /local/domain/1/device/vsnd/0/2/name = "SPDIF"
+ *
+ *----------------------------- Stream 0, playback ----------------------------
+ *
+ * /local/domain/1/device/vsnd/0/2/0/type = "p"
+ * /local/domain/1/device/vsnd/0/2/0/unique-id = "3"
+ *
+ * /local/domain/1/device/vsnd/0/2/0/ring-ref = "389"
+ * /local/domain/1/device/vsnd/0/2/0/event-channel = "152"
+ *
+ ******************************************************************************
+ *                            Backend XenBus Nodes
+ ******************************************************************************
+ *
+ *----------------------------- Protocol version ------------------------------
+ *
+ * versions
+ *      Values:         <string>
+ *
+ *      List of XENSND_LIST_SEPARATOR separated protocol versions supported
+ *      by the backend. For example "1,2,3".
+ *
+ ******************************************************************************
+ *                            Frontend XenBus Nodes
+ ******************************************************************************
+ *
+ *-------------------------------- Addressing ---------------------------------
+ *
+ * dom-id
+ *      Values:         <uint16_t>
+ *
+ *      Domain identifier.
+ *
+ * dev-id
+ *      Values:         <uint16_t>
+ *
+ *      Device identifier.
+ *
+ * pcm-dev-idx
+ *      Values:         <uint8_t>
+ *
+ *      Zero based contigous index of the PCM device.
+ *
+ * stream-idx
+ *      Values:         <uint8_t>
+ *
+ *      Zero based contigous index of the stream of the PCM device.
+ *
+ * The following pattern is used for addressing:
+ *   /local/domain/<dom-id>/device/vsnd/<dev-id>/<pcm-dev-idx>/<stream-idx>/...
+ *
+ *----------------------------- Protocol version ------------------------------
+ *
+ * version
+ *      Values:         <string>
+ *
+ *      Protocol version, chosen among the ones supported by the backend.
+ *
+ *------------------------------- PCM settings --------------------------------
+ *
+ * Every virtualized sound frontend has a set of PCM devices and streams, each
+ * could be individually configured. Part of the PCM configuration can be
+ * defined at higher level of the hierarchy and be fully or partially re-used
+ * by the underlying layers. These configuration values are:
+ *  o number of channels (min/max)
+ *  o supported sample rates
+ *  o supported sample formats.
+ * E.g. one can define these values for the whole card, device or stream.
+ * Every underlying layer in turn can re-define some or all of them to better
+ * fit its needs. For example, card may define number of channels to be
+ * in [1; 8] range, and some particular stream may be limited to [1; 2] only.
+ * The rule is that the underlying layer must be a subset of the upper layer
+ * range.
+ *
+ * channels-min
+ *      Values:         <uint8_t>
+ *
+ *      The minimum amount of channels that is supported, [1; channels-max].
+ *      Optional, if not set or omitted a value of 1 is used.
+ *
+ * channels-max
+ *      Values:         <uint8_t>
+ *
+ *      The maximum amount of channels that is supported.
+ *      Must be at least <channels-min>.
+ *
+ * sample-rates
+ *      Values:         <list of uint32_t>
+ *
+ *      List of supported sample rates separated by XENSND_LIST_SEPARATOR.
+ *      Sample rates are expressed as a list of decimal values w/o any
+ *      ordering requirement.
+ *
+ * sample-formats
+ *      Values:         <list of XENSND_PCM_FORMAT_XXX_STR>
+ *
+ *      List of supported sample formats separated by XENSND_LIST_SEPARATOR.
+ *      Items must not exceed XENSND_SAMPLE_FORMAT_MAX_LEN length.
+ *
+ * buffer-size
+ *      Values:         <uint32_t>
+ *
+ *      The maximum size in octets of the buffer to allocate per stream.
+ *
+ *----------------------- Virtual sound card settings -------------------------
+ * short-name
+ *      Values:         <char[32]>
+ *
+ *      Short name of the virtual sound card. Optional.
+ *
+ * long-name
+ *      Values:         <char[80]>
+ *
+ *      Long name of the virtual sound card. Optional.
+ *
+ *----------------------------- Device settings -------------------------------
+ * name
+ *      Values:         <char[80]>
+ *
+ *      Name of the sound device within the virtual sound card. Optional.
+ *
+ *----------------------------- Stream settings -------------------------------
+ *
+ * type
+ *      Values:         "p", "c"
+ *
+ *      Stream type: "p" - playback stream, "c" - capture stream
+ *
+ *      If both capture and playback are needed then two streams need to be
+ *      defined under the same device.
+ *
+ * unique-id
+ *      Values:         <uint32_t>
+ *
+ *      After stream initialization it is assigned a unique ID (within the front
+ *      driver), so every stream of the frontend can be identified by the
+ *      backend by this ID. This is not equal to stream-idx as the later is
+ *      zero based within the device, but this index is contigous within the
+ *      driver.
+ *
+ *-------------------- Stream Request Transport Parameters --------------------
+ *
+ * event-channel
+ *      Values:         <uint32_t>
+ *
+ *      The identifier of the Xen event channel used to signal activity
+ *      in the ring buffer.
+ *
+ * ring-ref
+ *      Values:         <uint32_t>
+ *
+ *      The Xen grant reference granting permission for the backend to map
+ *      a sole page in a single page sized ring buffer.
+ *
+ ******************************************************************************
+ *                               STATE DIAGRAMS
+ ******************************************************************************
+ *
+ * Tool stack creates front and back state nodes with initial state
+ * XenbusStateInitialising.
+ * Tool stack creates and sets up frontend sound configuration nodes per domain.
+ *
+ * Front                                Back
+ * =================================    =====================================
+ * XenbusStateInitialising              XenbusStateInitialising
+ *                                       o Query backend device identification
+ *                                         data.
+ *                                       o Open and validate backend device.
+ *                                                      |
+ *                                                      |
+ *                                                      V
+ *                                      XenbusStateInitWait
+ *
+ * o Query frontend configuration
+ * o Allocate and initialize
+ *   event channels per configured
+ *   playback/capture stream.
+ * o Publish transport parameters
+ *   that will be in effect during
+ *   this connection.
+ *              |
+ *              |
+ *              V
+ * XenbusStateInitialised
+ *
+ *                                       o Query frontend transport parameters.
+ *                                       o Connect to the event channels.
+ *                                                      |
+ *                                                      |
+ *                                                      V
+ *                                      XenbusStateConnected
+ *
+ *  o Create and initialize OS
+ *    virtual sound device instances
+ *    as per configuration.
+ *              |
+ *              |
+ *              V
+ * XenbusStateConnected
+ *
+ *                                      XenbusStateUnknown
+ *                                      XenbusStateClosed
+ *                                      XenbusStateClosing
+ * o Remove virtual sound device
+ * o Remove event channels
+ *              |
+ *              |
+ *              V
+ * XenbusStateClosed
+ *
+ *------------------------------- Recovery flow -------------------------------
+ *
+ * In case of frontend unrecoverable errors backend handles that as
+ * if frontend goes into the XenbusStateClosed state.
+ *
+ * In case of backend unrecoverable errors frontend tries removing
+ * the virtualized device. If this is possible at the moment of error,
+ * then frontend goes into the XenbusStateInitialising state and is ready for
+ * new connection with backend. If the virtualized device is still in use and
+ * cannot be removed, then frontend goes into the XenbusStateReconfiguring state
+ * until either the virtualized device removed or backend initiates a new
+ * connection. On the virtualized device removal frontend goes into the
+ * XenbusStateInitialising state.
+ *
+ * Note on XenbusStateReconfiguring state of the frontend: if backend has
+ * unrecoverable errors then frontend cannot send requests to the backend
+ * and thus cannot provide functionality of the virtualized device anymore.
+ * After backend is back to normal the virtualized device may still hold some
+ * state: configuration in use, allocated buffers, client application state etc.
+ * So, in most cases, this will require frontend to implement complex recovery
+ * reconnect logic. Instead, by going into XenbusStateReconfiguring state,
+ * frontend will make sure no new clients of the virtualized device are
+ * accepted, allow existing client(s) to exit gracefully by signaling error
+ * state etc.
+ * Once all the clients are gone frontend can reinitialize the virtualized
+ * device and get into XenbusStateInitialising state again signaling the
+ * backend that a new connection can be made.
+ *
+ * There are multiple conditions possible under which frontend will go from
+ * XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS
+ * specific. For example:
+ * 1. The underlying OS framework may provide callbacks to signal that the last
+ *    client of the virtualized device has gone and the device can be removed
+ * 2. Frontend can schedule a deferred work (timer/tasklet/workqueue)
+ *    to periodically check if this is the right time to re-try removal of
+ *    the virtualized device.
+ * 3. By any other means.
+ *
+ ******************************************************************************
+ *                             PCM FORMATS
+ ******************************************************************************
+ *
+ * XENSND_PCM_FORMAT_<format>[_<endian>]
+ *
+ * format: <S/U/F><bits> or <name>
+ *     S - signed, U - unsigned, F - float
+ *     bits - 8, 16, 24, 32
+ *     name - MU_LAW, GSM, etc.
+ *
+ * endian: <LE/BE>, may be absent
+ *     LE - Little endian, BE - Big endian
+ */
+#define XENSND_PCM_FORMAT_S8		0
+#define XENSND_PCM_FORMAT_U8		1
+#define XENSND_PCM_FORMAT_S16_LE	2
+#define XENSND_PCM_FORMAT_S16_BE	3
+#define XENSND_PCM_FORMAT_U16_LE	4
+#define XENSND_PCM_FORMAT_U16_BE	5
+#define XENSND_PCM_FORMAT_S24_LE	6
+#define XENSND_PCM_FORMAT_S24_BE	7
+#define XENSND_PCM_FORMAT_U24_LE	8
+#define XENSND_PCM_FORMAT_U24_BE	9
+#define XENSND_PCM_FORMAT_S32_LE	10
+#define XENSND_PCM_FORMAT_S32_BE	11
+#define XENSND_PCM_FORMAT_U32_LE	12
+#define XENSND_PCM_FORMAT_U32_BE	13
+#define XENSND_PCM_FORMAT_F32_LE	14 /* 4-byte float, IEEE-754 32-bit, */
+#define XENSND_PCM_FORMAT_F32_BE	15 /* range -1.0 to 1.0              */
+#define XENSND_PCM_FORMAT_F64_LE	16 /* 8-byte float, IEEE-754 64-bit, */
+#define XENSND_PCM_FORMAT_F64_BE	17 /* range -1.0 to 1.0              */
+#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE 18
+#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE 19
+#define XENSND_PCM_FORMAT_MU_LAW	20
+#define XENSND_PCM_FORMAT_A_LAW		21
+#define XENSND_PCM_FORMAT_IMA_ADPCM	22
+#define XENSND_PCM_FORMAT_MPEG		23
+#define XENSND_PCM_FORMAT_GSM		24
+
+/*
+ ******************************************************************************
+ *                             REQUEST CODES
+ ******************************************************************************
+ */
+#define XENSND_OP_OPEN			0
+#define XENSND_OP_CLOSE			1
+#define XENSND_OP_READ			2
+#define XENSND_OP_WRITE			3
+#define XENSND_OP_SET_VOLUME		4
+#define XENSND_OP_GET_VOLUME		5
+#define XENSND_OP_MUTE			6
+#define XENSND_OP_UNMUTE		7
+
+/*
+ ******************************************************************************
+ *               XENSTORE FIELD AND PATH NAME STRINGS, HELPERS
+ ******************************************************************************
+ */
+#define XENSND_DRIVER_NAME		"vsnd"
+
+#define XENSND_LIST_SEPARATOR		","
+/* Field names */
+#define XENSND_FIELD_BE_VERSIONS	"versions"
+#define XENSND_FIELD_FE_VERSION		"version"
+#define XENSND_FIELD_VCARD_SHORT_NAME	"short-name"
+#define XENSND_FIELD_VCARD_LONG_NAME	"long-name"
+#define XENSND_FIELD_RING_REF		"ring-ref"
+#define XENSND_FIELD_EVT_CHNL		"event-channel"
+#define XENSND_FIELD_DEVICE_NAME	"name"
+#define XENSND_FIELD_TYPE		"type"
+#define XENSND_FIELD_STREAM_UNIQUE_ID	"unique-id"
+#define XENSND_FIELD_CHANNELS_MIN	"channels-min"
+#define XENSND_FIELD_CHANNELS_MAX	"channels-max"
+#define XENSND_FIELD_SAMPLE_RATES	"sample-rates"
+#define XENSND_FIELD_SAMPLE_FORMATS	"sample-formats"
+#define XENSND_FIELD_BUFFER_SIZE	"buffer-size"
+
+/* Stream type field values. */
+#define XENSND_STREAM_TYPE_PLAYBACK	"p"
+#define XENSND_STREAM_TYPE_CAPTURE	"c"
+/* Sample rate max string length */
+#define XENSND_SAMPLE_RATE_MAX_LEN	11
+/* Sample format field values */
+#define XENSND_SAMPLE_FORMAT_MAX_LEN	24
+
+#define XENSND_PCM_FORMAT_S8_STR	"s8"
+#define XENSND_PCM_FORMAT_U8_STR	"u8"
+#define XENSND_PCM_FORMAT_S16_LE_STR	"s16_le"
+#define XENSND_PCM_FORMAT_S16_BE_STR	"s16_be"
+#define XENSND_PCM_FORMAT_U16_LE_STR	"u16_le"
+#define XENSND_PCM_FORMAT_U16_BE_STR	"u16_be"
+#define XENSND_PCM_FORMAT_S24_LE_STR	"s24_le"
+#define XENSND_PCM_FORMAT_S24_BE_STR	"s24_be"
+#define XENSND_PCM_FORMAT_U24_LE_STR	"u24_le"
+#define XENSND_PCM_FORMAT_U24_BE_STR	"u24_be"
+#define XENSND_PCM_FORMAT_S32_LE_STR	"s32_le"
+#define XENSND_PCM_FORMAT_S32_BE_STR	"s32_be"
+#define XENSND_PCM_FORMAT_U32_LE_STR	"u32_le"
+#define XENSND_PCM_FORMAT_U32_BE_STR	"u32_be"
+#define XENSND_PCM_FORMAT_F32_LE_STR	"float_le"
+#define XENSND_PCM_FORMAT_F32_BE_STR	"float_be"
+#define XENSND_PCM_FORMAT_F64_LE_STR	"float64_le"
+#define XENSND_PCM_FORMAT_F64_BE_STR	"float64_be"
+#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR "iec958_subframe_le"
+#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR "iec958_subframe_be"
+#define XENSND_PCM_FORMAT_MU_LAW_STR	"mu_law"
+#define XENSND_PCM_FORMAT_A_LAW_STR	"a_law"
+#define XENSND_PCM_FORMAT_IMA_ADPCM_STR	"ima_adpcm"
+#define XENSND_PCM_FORMAT_MPEG_STR	"mpeg"
+#define XENSND_PCM_FORMAT_GSM_STR	"gsm"
+
+
+/*
+ ******************************************************************************
+ *                          STATUS RETURN CODES
+ ******************************************************************************
+ *
+ * Status return code is zero on success and -XEN_EXX on failure.
+ *
+ ******************************************************************************
+ *                              Assumptions
+ ******************************************************************************
+ * o usage of grant reference 0 as invalid grant reference:
+ *   grant reference 0 is valid, but never exposed to a PV driver,
+ *   because of the fact it is already in use/reserved by the PV console.
+ * o all references in this document to page sizes must be treated
+ *   as pages of size XEN_PAGE_SIZE unless otherwise noted.
+ *
+ ******************************************************************************
+ *       Description of the protocol between frontend and backend driver
+ ******************************************************************************
+ *
+ * The two halves of a Para-virtual sound driver communicate with
+ * each other using shared pages and event channels.
+ * Shared page contains a ring with request/response packets.
+ *
+ * Packets, used for input/output operations, e.g. read/write, set/get volume,
+ * etc., provide offset/length fields in order to allow asynchronous protocol
+ * operation with buffer space sharing: part of the buffer allocated at
+ * XENSND_OP_OPEN can be used for audio samples and part, for example,
+ * for volume control.
+ *
+ * All reserved fields in the structures below must be 0.
+ *
+ *---------------------------------- Requests ---------------------------------
+ *
+ * All request packets have the same length (32 octets)
+ * All request packets have common header:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |    operation   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ *   id - uint16_t, private guest value, echoed in response
+ *   operation - uint8_t, operation code, XENSND_OP_???
+ *
+ * For all packets which use offset and length:
+ *   offset - uint32_t, read or write data offset within the shared buffer,
+ *     passed with XENSND_OP_OPEN request, octets,
+ *     [0; XENSND_OP_OPEN.buffer_sz - 1].
+ *   length - uint32_t, read or write data length, octets
+ *
+ * Request open - open a PCM stream for playback or capture:
+ *
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                | XENSND_OP_OPEN |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                             pcm_rate                              | 12
+ * +----------------+----------------+----------------+----------------+
+ * |  pcm_format    |  pcm_channels  |             reserved            | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             buffer_sz                             | 20
+ * +----------------+----------------+----------------+----------------+
+ * |                           gref_directory                          | 24
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 28
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * pcm_rate - uint32_t, stream data rate, Hz
+ * pcm_format - uint8_t, XENSND_PCM_FORMAT_XXX value
+ * pcm_channels - uint8_t, number of channels of this stream,
+ *   [channels-min; channels-max]
+ * buffer_sz - uint32_t, buffer size to be allocated, octets
+ * gref_directory - grant_ref_t, a reference to the first shared page
+ *   describing shared buffer references. At least one page exists. If shared
+ *   buffer size  (buffer_sz) exceeds what can be addressed by this single page,
+ *   then reference to the next page must be supplied (see gref_dir_next_page
+ *   below)
+ */
+
+struct xensnd_open_req {
+	uint32_t pcm_rate;
+	uint8_t pcm_format;
+	uint8_t pcm_channels;
+	uint16_t reserved;
+	uint32_t buffer_sz;
+	grant_ref_t gref_directory;
+};
+
+/*
+ * Shared page for XENSND_OP_OPEN buffer descriptor (gref_directory in the
+ *   request) employs a list of pages, describing all pages of the shared data
+ *   buffer:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |                        gref_dir_next_page                         | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                              gref[0]                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                              gref[i]                              | i*4+8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             gref[N - 1]                           | N*4+8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * gref_dir_next_page - grant_ref_t, reference to the next page describing
+ *   page directory. Must be 0 if there are no more pages in the list.
+ * gref[i] - grant_ref_t, reference to a shared page of the buffer
+ *   allocated at XENSND_OP_OPEN
+ *
+ * Number of grant_ref_t entries in the whole page directory is not
+ * passed, but instead can be calculated as:
+ *   num_grefs_total = (XENSND_OP_OPEN.buffer_sz + XEN_PAGE_SIZE - 1) /
+ *       XEN_PAGE_SIZE
+ */
+
+struct xensnd_page_directory {
+	grant_ref_t gref_dir_next_page;
+	grant_ref_t gref[1]; /* Variable length */
+};
+
+/*
+ *  Request close - close an opened pcm stream:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                | XENSND_OP_CLOSE|    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Request read/write - used for read (for capture) or write (for playback):
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |   operation    |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                              offset                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                              length                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * operation - XENSND_OP_READ for read or XENSND_OP_WRITE for write
+ */
+
+struct xensnd_rw_req {
+	uint32_t offset;
+	uint32_t length;
+};
+
+/*
+ * Request set/get volume - set/get channels' volume of the stream given:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |   operation    |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                              offset                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                              length                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * operation - XENSND_OP_SET_VOLUME for volume set
+ *   or XENSND_OP_GET_VOLUME for volume get
+ * Buffer passed with XENSND_OP_OPEN is used to exchange volume
+ * values:
+ *
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |                             channel[0]                            | 4
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             channel[i]                            | i*4
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                           channel[N - 1]                          | (N-1)*4
+ * +----------------+----------------+----------------+----------------+
+ *
+ * N = XENSND_OP_OPEN.pcm_channels
+ * i - uint8_t, index of a channel
+ * channel[i] - sint32_t, volume of i-th channel
+ * Volume is expressed as a signed value in steps of 0.001 dB,
+ * while 0 being 0 dB.
+ *
+ * Request mute/unmute - mute/unmute stream:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |   operation    |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                              offset                               | 12
+ * +----------------+----------------+----------------+----------------+
+ * |                              length                               | 16
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * operation - XENSND_OP_MUTE for mute or XENSND_OP_UNMUTE for unmute
+ * Buffer passed with XENSND_OP_OPEN is used to exchange mute/unmute
+ * values:
+ *
+ *                                   0                                 octet
+ * +----------------+----------------+----------------+----------------+
+ * |                             channel[0]                            | 4
+ * +----------------+----------------+----------------+----------------+
+ * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             channel[i]                            | i*4
+ * +----------------+----------------+----------------+----------------+
+ * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                           channel[N - 1]                          | (N-1)*4
+ * +----------------+----------------+----------------+----------------+
+ *
+ * N = XENSND_OP_OPEN.pcm_channels
+ * i - uint8_t, index of a channel
+ * channel[i] - uint8_t, non-zero if i-th channel needs to be muted/unmuted
+ *
+ *------------------------------------ N.B. -----------------------------------
+ *
+ * The 'struct xensnd_rw_req' is also used for XENSND_OP_SET_VOLUME,
+ * XENSND_OP_GET_VOLUME, XENSND_OP_MUTE, XENSND_OP_UNMUTE.
+ */
+
+/*
+ *---------------------------------- Responses --------------------------------
+ *
+ * All response packets have the same length (32 octets)
+ *
+ * Response for all requests:
+ *         0                1                 2               3        octet
+ * +----------------+----------------+----------------+----------------+
+ * |               id                |    operation   |    reserved    | 4
+ * +----------------+----------------+----------------+----------------+
+ * |                              status                               | 8
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 12
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * |                             reserved                              | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * id - uint16_t, copied from the request
+ * operation - uint8_t, XENSND_OP_* - copied from request
+ * status - int32_t, response status, zero on success and -XEN_EXX on failure
+ */
+
+struct xensnd_req {
+	uint16_t id;
+	uint8_t operation;
+	uint8_t reserved[5];
+	union {
+		struct xensnd_open_req open;
+		struct xensnd_rw_req rw;
+		uint8_t reserved[24];
+	} op;
+};
+
+struct xensnd_resp {
+	uint16_t id;
+	uint8_t operation;
+	uint8_t reserved;
+	int32_t status;
+	uint8_t reserved1[24];
+};
+
+DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp);
+
+#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index b5486e648607..c44a2ee8c8f8 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -22,6 +22,8 @@ void xen_timer_resume(void);
 void xen_arch_resume(void);
 void xen_arch_suspend(void);
 
+void xen_reboot(int reason);
+
 void xen_resume_notifier_register(struct notifier_block *nb);
 void xen_resume_notifier_unregister(struct notifier_block *nb);
 
@@ -34,11 +36,25 @@ u64 xen_steal_clock(int cpu);
 int xen_setup_shutdown_event(void);
 
 extern unsigned long *xen_contiguous_bitmap;
+
+#ifdef CONFIG_XEN_PV
 int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
 				unsigned int address_bits,
 				dma_addr_t *dma_handle);
 
 void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order);
+#else
+static inline int xen_create_contiguous_region(phys_addr_t pstart,
+					       unsigned int order,
+					       unsigned int address_bits,
+					       dma_addr_t *dma_handle)
+{
+	return 0;
+}
+
+static inline void xen_destroy_contiguous_region(phys_addr_t pstart,
+						 unsigned int order) { }
+#endif
 
 struct vm_area_struct;
 
@@ -120,6 +136,9 @@ efi_status_t xen_efi_update_capsule(efi_capsule_header_t **capsules,
 efi_status_t xen_efi_query_capsule_caps(efi_capsule_header_t **capsules,
 					unsigned long count, u64 *max_size,
 					int *reset_type);
+void xen_efi_reset_system(int reset_type, efi_status_t status,
+			  unsigned long data_size, efi_char16_t *data);
+
 
 #ifdef CONFIG_PREEMPT