Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyper-v updates from Wei Liu:

 - a series from Andrea to support channel reassignment

 - a series from Vitaly to clean up Vmbus message handling

 - a series from Michael to clean up and augment hyperv-tlfs.h

 - patches from Andy to clean up GUID usage in Hyper-V code

 - a few other misc patches

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (29 commits)
  Drivers: hv: vmbus: Resolve more races involving init_vp_index()
  Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplug
  vmbus: Replace zero-length array with flexible-array
  Driver: hv: vmbus: drop a no long applicable comment
  hyper-v: Switch to use UUID types directly
  hyper-v: Replace open-coded variant of %*phN specifier
  hyper-v: Supply GUID pointer to printf() like functions
  hyper-v: Use UUID API for exporting the GUID (part 2)
  asm-generic/hyperv: Add definitions for Get/SetVpRegister hypercalls
  x86/hyperv: Split hyperv-tlfs.h into arch dependent and independent files
  x86/hyperv: Remove HV_PROCESSOR_POWER_STATE #defines
  KVM: x86: hyperv: Remove duplicate definitions of Reference TSC Page
  drivers: hv: remove redundant assignment to pointer primary_channel
  scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned
  Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type
  Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug
  Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic
  PCI: hv: Prepare hv_compose_msi_msg() for the VMBus-channel-interrupt-to-vCPU reassignment functionality
  Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. channel removal
  hv_utils: Always execute the fcopy and vss callbacks in a tasklet
  ...

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 533c8b82b344..857290dcfd95 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -117,8 +117,6 @@ int hv_synic_alloc(void)
 			pr_err("Unable to allocate post msg page\n");
 			goto err;
 		}
-
-		INIT_LIST_HEAD(&hv_cpu->chan_list);
 	}
 
 	return 0;
@@ -246,10 +244,18 @@ int hv_synic_cleanup(unsigned int cpu)
 	unsigned long flags;
 
 	/*
+	 * Hyper-V does not provide a way to change the connect CPU once
+	 * it is set; we must prevent the connect CPU from going offline.
+	 */
+	if (cpu == VMBUS_CONNECT_CPU)
+		return -EBUSY;
+
+	/*
 	 * Search for channels which are bound to the CPU we're about to
-	 * cleanup. In case we find one and vmbus is still connected we need to
-	 * fail, this will effectively prevent CPU offlining. There is no way
-	 * we can re-bind channels to different CPUs for now.
+	 * cleanup.  In case we find one and vmbus is still connected, we
+	 * fail; this will effectively prevent CPU offlining.
+	 *
+	 * TODO: Re-bind the channels to different CPUs.
 	 */
 	mutex_lock(&vmbus_connection.channel_mutex);
 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {