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2023-06-28x86/apic: Fix kernel panic when booting with intremap=off and x2apic_physDheeraj Kumar Srivastava
[ Upstream commit 85d38d5810e285d5aec7fb5283107d1da70c12a9 ] When booting with "intremap=off" and "x2apic_phys" on the kernel command line, the physical x2APIC driver ends up being used even when x2APIC mode is disabled ("intremap=off" disables x2APIC mode). This happens because the first compound condition check in x2apic_phys_probe() is false due to x2apic_mode == 0 and so the following one returns true after default_acpi_madt_oem_check() having already selected the physical x2APIC driver. This results in the following panic: kernel BUG at arch/x86/kernel/apic/io_apic.c:2409! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc2-ver4.1rc2 #2 Hardware name: Dell Inc. PowerEdge R6515/07PXPY, BIOS 2.3.6 07/06/2021 RIP: 0010:setup_IO_APIC+0x9c/0xaf0 Call Trace: <TASK> ? native_read_msr apic_intr_mode_init x86_late_time_init start_kernel x86_64_start_reservations x86_64_start_kernel secondary_startup_64_no_verify </TASK> which is: setup_IO_APIC: apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n"); for_each_ioapic(ioapic) BUG_ON(mp_irqdomain_create(ioapic)); Return 0 to denote that x2APIC has not been enabled when probing the physical x2APIC driver. [ bp: Massage commit message heavily. ] Fixes: 9ebd680bd029 ("x86, apic: Use probe routines to simplify apic selection") Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kishon Vijay Abraham I <kvijayab@amd.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230616212236.1389-1-dheerajkumar.srivastava@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11x86/ioapic: Don't return 0 from arch_dynirq_lower_bound()Saurabh Sengar
[ Upstream commit 5af507bef93c09a94fb8f058213b489178f4cbe5 ] arch_dynirq_lower_bound() is invoked by the core interrupt code to retrieve the lowest possible Linux interrupt number for dynamically allocated interrupts like MSI. The x86 implementation uses this to exclude the IO/APIC GSI space. This works correctly as long as there is an IO/APIC registered, but returns 0 if not. This has been observed in VMs where the BIOS does not advertise an IO/APIC. 0 is an invalid interrupt number except for the legacy timer interrupt on x86. The return value is unchecked in the core code, so it ends up to allocate interrupt number 0 which is subsequently considered to be invalid by the caller, e.g. the MSI allocation code. The function has already a check for 0 in the case that an IO/APIC is registered, as ioapic_dynirq_base is 0 in case of device tree setups. Consolidate this and zero check for both ioapic_dynirq_base and gsi_top, which is used in the case that no IO/APIC is registered. Fixes: 3e5bedc2c258 ("x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines") Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/1679988604-20308-1-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11x86/apic: Fix atomic update of offset in reserve_eilvt_offset()Uros Bizjak
[ Upstream commit f96fb2df3eb31ede1b34b0521560967310267750 ] The detection of atomic update failure in reserve_eilvt_offset() is not correct. The value returned by atomic_cmpxchg() should be compared to the old value from the location to be updated. If these two are the same, then atomic update succeeded and "eilvt_offsets[offset]" location is updated to "new" in an atomic way. Otherwise, the atomic update failed and it should be retried with the value from "eilvt_offsets[offset]" - exactly what atomic_try_cmpxchg() does in a correct and more optimal way. Fixes: a68c439b1966c ("apic, x86: Check if EILVT APIC registers are available (AMD only)") Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230227160917.107820-1-ubizjak@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31x86/apic: Handle no CONFIG_X86_X2APIC on systems with x2APIC enabled by BIOSMateusz Jończyk
[ Upstream commit e3998434da4f5b1f57f8d6a8a9f8502ee3723bae ] A kernel that was compiled without CONFIG_X86_X2APIC was unable to boot on platforms that have x2APIC already enabled in the BIOS before starting the kernel. The kernel was supposed to panic with an approprite error message in validate_x2apic() due to the missing X2APIC support. However, validate_x2apic() was run too late in the boot cycle, and the kernel tried to initialize the APIC nonetheless. This resulted in an earlier panic in setup_local_APIC() because the APIC was not registered. In my experiments, a panic message in setup_local_APIC() was not visible in the graphical console, which resulted in a hang with no indication what has gone wrong. Instead of calling panic(), disable the APIC, which results in a somewhat working system with the PIC only (and no SMP). This way the user is able to diagnose the problem more easily. Disabling X2APIC mode is not an option because it's impossible on systems with locked x2APIC. The proper place to disable the APIC in this case is in check_x2apic(), which is called early from setup_arch(). Doing this in __apic_intr_mode_select() is too late. Make check_x2apic() unconditionally available and remove the empty stub. Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Reported-by: Robert Elliott (Servers) <elliott@hpe.com> Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/d573ba1c-0dc4-3016-712a-cc23a8a33d42@molgen.mpg.de Link: https://lore.kernel.org/lkml/20220911084711.13694-3-mat.jonczyk@o2.pl Link: https://lore.kernel.org/all/20221129215008.7247-1-mat.jonczyk@o2.pl Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31x86/apic: Don't disable x2APIC if lockedDaniel Sneddon
The APIC supports two modes, legacy APIC (or xAPIC), and Extended APIC (or x2APIC). X2APIC mode is mostly compatible with legacy APIC, but it disables the memory-mapped APIC interface in favor of one that uses MSRs. The APIC mode is controlled by the EXT bit in the APIC MSR. The MMIO/xAPIC interface has some problems, most notably the APIC LEAK [1]. This bug allows an attacker to use the APIC MMIO interface to extract data from the SGX enclave. Introduce support for a new feature that will allow the BIOS to lock the APIC in x2APIC mode. If the APIC is locked in x2APIC mode and the kernel tries to disable the APIC or revert to legacy APIC mode a GP fault will occur. Introduce support for a new MSR (IA32_XAPIC_DISABLE_STATUS) and handle the new locked mode when the LEGACY_XAPIC_DISABLED bit is set by preventing the kernel from trying to disable the x2APIC. On platforms with the IA32_XAPIC_DISABLE_STATUS MSR, if SGX or TDX are enabled the LEGACY_XAPIC_DISABLED will be set by the BIOS. If legacy APIC is required, then it SGX and TDX need to be disabled in the BIOS. [1]: https://aepicleak.com/aepicleak.pdf Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com> Link: https://lkml.kernel.org/r/20220816231943.1152579-1-daniel.sneddon@linux.intel.com
2022-08-07Merge tag 'mm-nonmm-stable-2022-08-06-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc updates from Andrew Morton: "Updates to various subsystems which I help look after. lib, ocfs2, fatfs, autofs, squashfs, procfs, etc. A relatively small amount of material this time" * tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) scripts/gdb: ensure the absolute path is generated on initial source MAINTAINERS: kunit: add David Gow as a maintainer of KUnit mailmap: add linux.dev alias for Brendan Higgins mailmap: update Kirill's email profile: setup_profiling_timer() is moslty not implemented ocfs2: fix a typo in a comment ocfs2: use the bitmap API to simplify code ocfs2: remove some useless functions lib/mpi: fix typo 'the the' in comment proc: add some (hopefully) insightful comments bdi: remove enum wb_congested_state kernel/hung_task: fix address space of proc_dohung_task_timeout_secs lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t() squashfs: support reading fragments in readahead call squashfs: implement readahead squashfs: always build "file direct" version of page actor Revert "squashfs: provide backing_dev_info in order to disable read-ahead" fs/ocfs2: Fix spelling typo in comment ia64: old_rr4 added under CONFIG_HUGETLB_PAGE proc: fix test for "vsyscall=xonly" boot option ...
2022-07-29profile: setup_profiling_timer() is moslty not implementedBen Dooks
The setup_profiling_timer() is mostly un-implemented by many architectures. In many places it isn't guarded by CONFIG_PROFILE which is needed for it to be used. Make it a weak symbol in kernel/profile.c and remove the 'return -EINVAL' implementations from the kenrel. There are a couple of architectures which do return 0 from the setup_profiling_timer() function but they don't seem to do anything else with it. To keep the /proc compatibility for now, leave these for a future update or removal. On ARM, this fixes the following sparse warning: arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static? Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-24KVM: x86: lapic: Rename [GET/SET]_APIC_DEST_FIELD to [GET/SET]_XAPIC_DEST_FIELDSuravee Suthikulpanit
To signify that the macros only support 8-bit xAPIC destination ID. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220519102709.24125-3-suravee.suthikulpanit@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-23Merge tag 'x86_misc_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 updates from Borislav Petkov: "A variety of fixes which don't fit any other tip bucket: - Remove unnecessary function export - Correct asm constraint - Fix __setup handlers retval" * tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Cleanup the control_va_addr_alignment() __setup handler x86: Fix return value of __setup handlers x86/delay: Fix the wrong asm constraint in delay_loop() x86/amd_nb: Unexport amd_cache_northbridges()
2022-05-23Merge tag 'x86_apic_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 APIC updates from Borislav Petkov: - Always do default APIC routing setup so that cpumasks are properly allocated and are present when later accessed ("nosmp" and x2APIC) - Clarify the bit overlap between an old APIC and a modern, integrated one * tag 'x86_apic_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Do apic driver probe for "nosmp" use case x86/apic: Clarify i82489DX bit overlap in APIC_LVT0
2022-05-23Merge tag 'x86_platform_for_v5.19_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Borislav Petkov: - A couple of changes enabling SGI UV5 support * tag 'x86_platform_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Log gap hole end size x86/platform/uv: Update TSC sync state for UV5 x86/platform/uv: Update NMI Handler for UV5
2022-05-04x86: Fix return value of __setup handlersRandy Dunlap
__setup() handlers should return 1 to obsolete_checksetup() in init/main.c to indicate that the boot option has been handled. A return of 0 causes the boot option/value to be listed as an Unknown kernel parameter and added to init's (limited) argument (no '=') or environment (with '=') strings. So return 1 from these x86 __setup handlers. Examples: Unknown kernel command line parameters "apicpmtimer BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable", will be passed to user space. Run /sbin/init as init process with arguments: /sbin/init apicpmtimer with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc8 vdso=1 ring3mwait=disable Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Fixes: 77b52b4c5c66 ("x86: add "debugpat" boot option") Fixes: e16fd002afe2 ("x86/cpufeature: Enable RING3MWAIT for Knights Landing") Fixes: b8ce33590687 ("x86_64: convert to clock events") Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Link: https://lore.kernel.org/r/20220314012725.26661-1-rdunlap@infradead.org
2022-05-01x86/apic: Do apic driver probe for "nosmp" use caseKuppuswamy Sathyanarayanan
For the "nosmp" use case, the APIC initialization code selects "APIC_SYMMETRIC_IO_NO_ROUTING" as the default interrupt mode and avoids probing APIC drivers. This works well for the default APIC modes, but for the x2APIC case the probe function is required to allocate the cluster_hotplug mask. So in the APIC_SYMMETRIC_IO_NO_ROUTING case when the x2APIC is initialized it dereferences a NULL pointer and the kernel crashes. This was observed on a TDX platform where x2APIC is enabled and "nosmp" command line option is allowed. To fix this issue, probe APIC drivers via default_setup_apic_routing() for the APIC_SYMMETRIC_IO_NO_ROUTING interrupt mode too. Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/a64f864e1114bcd63593286aaf61142cfce384ea.1650076869.git.sathyanarayanan.kuppuswamy@intel.com
2022-04-13x86/apic: Clarify i82489DX bit overlap in APIC_LVT0Thomas Gleixner
Daniel stumbled over the bit overlap of the i82498DX external APIC and the TSC deadline timer configuration bit in modern APICs, which is neither documented in the code nor in the current SDM. Maciej provided links to the original i82489DX/486 documentation. See Link. Remove the i82489DX macro maze, use a i82489DX specific define in the apic code and document the overlap in a comment. Reported-by: Daniel Vacek <neelx@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/87ee22f3ci.ffs@tglx
2022-04-07x86/tdx/ioapic: Add shared bit for IOAPIC base addressIsaku Yamahata
The kernel interacts with each bare-metal IOAPIC with a special MMIO page. When running under KVM, the guest's IOAPICs are emulated by KVM. When running as a TDX guest, the guest needs to mark each IOAPIC mapping as "shared" with the host. This ensures that TDX private protections are not applied to the page, which allows the TDX host emulation to work. ioremap()-created mappings such as virtio will be marked as shared by default. However, the IOAPIC code does not use ioremap() and instead uses the fixmap mechanism. Introduce a special fixmap helper just for the IOAPIC code. Ensure that it marks IOAPIC pages as "shared". This replaces set_fixmap_nocache() with __set_fixmap() since __set_fixmap() allows custom 'prot' values. AMD SEV gets IOAPIC pages shared because FIXMAP_PAGE_NOCACHE has _ENC bit clear. TDX has to set bit to share the page with the host. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-29-kirill.shutemov@linux.intel.com
2022-04-07x86/acpi/x86/boot: Add multiprocessor wake-up supportKuppuswamy Sathyanarayanan
Secondary CPU startup is currently performed with something called the "INIT/SIPI protocol". This protocol requires assistance from VMMs to boot guests. As should be a familiar story by now, that support can not be provded to TDX guests because TDX VMMs are not trusted by guests. To remedy this situation a new[1] "Multiprocessor Wakeup Structure" has been added to to an existing ACPI table (MADT). This structure provides the physical address of a "mailbox". A write to the mailbox then steers the secondary CPU to the boot code. Add ACPI MADT wake structure parsing support and wake support. Use this support to wake CPUs whenever it is present instead of INIT/SIPI. While this structure can theoretically be used on 32-bit kernels, there are no 32-bit TDX guest kernels. It has not been tested and can not practically *be* tested on 32-bit. Make it 64-bit only. 1. Details about the new structure can be found in ACPI v6.4, in the "Multiprocessor Wakeup Structure" section. Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-22-kirill.shutemov@linux.intel.com
2022-04-07x86/platform/uv: Log gap hole end sizeMike Travis
Show value of gap end in the kernel log which equates to number of physical address bits used by system. Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220406195149.228164-4-steve.wahl@hpe.com
2022-04-07x86/platform/uv: Update TSC sync state for UV5Mike Travis
The UV5 platform synchronizes the TSCs among all chassis, and will not proceed to OS boot without achieving synchronization. Previous UV platforms provided a register indicating successful synchronization. This is no longer available on UV5. On this platform TSC_ADJUST should not be reset by the kernel. Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220406195149.228164-3-steve.wahl@hpe.com
2022-01-23Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linuxLinus Torvalds
Pull bitmap updates from Yury Norov: - introduce for_each_set_bitrange() - use find_first_*_bit() instead of find_next_*_bit() where possible - unify for_each_bit() macros * tag 'bitmap-5.17-rc1' of git://github.com/norov/linux: vsprintf: rework bitmap_list_string lib: bitmap: add performance test for bitmap_print_to_pagebuf bitmap: unify find_bit operations mm/percpu: micro-optimize pcpu_is_populated() Replace for_each_*_bit_from() with for_each_*_bit() where appropriate find: micro-optimize for_each_{set,clear}_bit() include/linux: move for_each_bit() macros from bitops.h to find.h cpumask: replace cpumask_next_* with cpumask_first_* where appropriate tools: sync tools/bitmap with mother linux all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate cpumask: use find_first_and_bit() lib: add find_first_and_bit() arch: remove GENERIC_FIND_FIRST_BIT entirely include: move find.h from asm_generic to linux bitops: move find_bit_*_le functions from le.h to find.h bitops: protect find_first_{,zero}_bit properly
2022-01-15Replace for_each_*_bit_from() with for_each_*_bit() where appropriateYury Norov
A couple of kernel functions call for_each_*_bit_from() with start bit equal to 0. Replace them with for_each_*_bit(). No functional changes, but might improve on readability. Signed-off-by: Yury Norov <yury.norov@gmail.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2021-12-16x86/apic/msi: Use PCI device MSI propertyThomas Gleixner
instead of fiddling with MSI descriptors. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20211210221813.372357371@linutronix.de
2021-12-09PCI/MSI: Make arch_restore_msi_irqs() less horrible.Thomas Gleixner
Make arch_restore_msi_irqs() return a boolean which indicates whether the core code should restore the MSI message or not. Get rid of the indirection in x86. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # PCI Link: https://lore.kernel.org/r/20211206210224.485668098@linutronix.de
2021-12-09genirq/msi, treewide: Use a named struct for PCI/MSI attributesThomas Gleixner
The unnamed struct sucks and is in the way of further cleanups. Stick the PCI related MSI data into a real data structure and cleanup all users. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20211206210224.374863119@linutronix.de
2021-10-29x86/apic: Reduce cache line misses in __x2apic_send_IPI_mask()Eric Dumazet
Using per-cpu storage for @x86_cpu_to_logical_apicid is not optimal. Broadcast IPI will need at least one cache line per cpu to access this field. __x2apic_send_IPI_mask() is using standard bitmask operators. By converting x86_cpu_to_logical_apicid to an array, we divide by 16x number of needed cache lines, because we find 16 values per cache line. CPU prefetcher can kick nicely. Also move @cluster_masks to READ_MOSTLY section to avoid false sharing. Tested on a dual socket host with 256 cpus, cost for a full broadcast is now 11 usec instead of 33 usec. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20211007143556.574911-1-eric.dumazet@gmail.com
2021-08-30Merge tag 'x86-irq-2021-08-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 PIRQ updates from Thomas Gleixner: "A set of updates to support port 0x22/0x23 based PCI configuration space which can be found on various ALi chipsets and is also available on older Intel systems which expose a PIRQ router. While the Intel support is more or less nostalgia, the ALi chips are still in use on popular embedded boards used for routers" * tag 'x86-irq-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Fix typo s/ECLR/ELCR/ for the PIC register x86: Avoid magic number with ELCR register accesses x86/PCI: Add support for the Intel 82426EX PIRQ router x86/PCI: Add support for the Intel 82374EB/82374SB (ESC) PIRQ router x86/PCI: Add support for the ALi M1487 (IBC) PIRQ router x86: Add support for 0x22/0x23 port I/O configuration space
2021-08-10x86: Avoid magic number with ELCR register accessesMaciej W. Rozycki
Define PIC_ELCR1 and PIC_ELCR2 macros for accesses to the ELCR registers implemented by many chipsets in their embedded 8259A PIC cores, avoiding magic numbers that are difficult to handle, and complementing the macros we already have for registers originally defined with discrete 8259A PIC implementations. No functional change. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107200237300.9461@angie.orcam.me.uk
2021-08-10x86: Add support for 0x22/0x23 port I/O configuration spaceMaciej W. Rozycki
Define macros and accessors for the configuration space addressed indirectly with an index register and a data register at the port I/O locations of 0x22 and 0x23 respectively. This space is defined by the Intel MultiProcessor Specification for the IMCR register used to switch between the PIC and the APIC mode[1], by Cyrix processors for their configuration[2][3], and also some chipsets. Given the lack of atomicity with the indirect addressing a spinlock is required to protect accesses, although for Cyrix processors it is enough if accesses are executed with interrupts locally disabled, because the registers are local to the accessing CPU, and IMCR is only ever poked at by the BSP and early enough for interrupts not to have been configured yet. Therefore existing code does not have to change or use the new spinlock and neither it does. Put the spinlock in a library file then, so that it does not get pulled unnecessarily for configurations that do not refer it. Convert Cyrix accessors to wrappers so as to retain the brevity and clarity of the `getCx86' and `setCx86' calls. References: [1] "MultiProcessor Specification", Version 1.4, Intel Corporation, Order Number: 242016-006, May 1997, Section 3.6.2.1 "PIC Mode", pp. 3-7, 3-8 [2] "5x86 Microprocessor", Cyrix Corporation, Order Number: 94192-00, July 1995, Section 2.3.2.4 "Configuration Registers", p. 2-23 [3] "6x86 Processor", Cyrix Corporation, Order Number: 94175-01, March 1996, Section 2.4.4 "6x86 Configuration Registers", p. 2-23 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107182353140.9461@angie.orcam.me.uk
2021-08-10x86/msi: Force affinity setup before startupThomas Gleixner
The X86 MSI mechanism cannot handle interrupt affinity changes safely after startup other than from an interrupt handler, unless interrupt remapping is enabled. The startup sequence in the generic interrupt code violates that assumption. Mark the irq chips with the new IRQCHIP_AFFINITY_PRE_STARTUP flag so that the default interrupt setting happens before the interrupt is started up for the first time. While the interrupt remapping MSI chip does not require this, there is no point in treating it differently as this might spare an interrupt to a CPU which is not in the default affinity mask. For the non-remapping case go to the direct write path when the interrupt is not yet started similar to the not yet activated case. Fixes: 18404756765c ("genirq: Expose default irq affinity mask (take 3)") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.886722080@linutronix.de
2021-08-10x86/ioapic: Force affinity setup before startupThomas Gleixner
The IO/APIC cannot handle interrupt affinity changes safely after startup other than from an interrupt handler. The startup sequence in the generic interrupt code violates that assumption. Mark the irq chip with the new IRQCHIP_AFFINITY_PRE_STARTUP flag so that the default interrupt setting happens before the interrupt is started up for the first time. Fixes: 18404756765c ("genirq: Expose default irq affinity mask (take 3)") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.832143400@linutronix.de
2021-05-29x86/apic: Mark _all_ legacy interrupts when IO/APIC is missingThomas Gleixner
PIC interrupts do not support affinity setting and they can end up on any online CPU. Therefore, it's required to mark the associated vectors as system-wide reserved. Otherwise, the corresponding irq descriptors are copied to the secondary CPUs but the vectors are not marked as assigned or reserved. This works correctly for the IO/APIC case. When the IO/APIC is disabled via config, kernel command line or lack of enumeration then all legacy interrupts are routed through the PIC, but nothing marks them as system-wide reserved vectors. As a consequence, a subsequent allocation on a secondary CPU can result in allocating one of these vectors, which triggers the BUG() in apic_update_vector() because the interrupt descriptor slot is not empty. Imran tried to work around that by marking those interrupts as allocated when a CPU comes online. But that's wrong in case that the IO/APIC is available and one of the legacy interrupts, e.g. IRQ0, has been switched to PIC mode because then marking them as allocated will fail as they are already marked as system vectors. Stay consistent and update the legacy vectors after attempting IO/APIC initialization and mark them as system vectors in case that no IO/APIC is available. Fixes: 69cde0004a4b ("x86/vector: Use matrix allocator for vector assignment") Reported-by: Imran Khan <imran.f.khan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20210519233928.2157496-1-imran.f.khan@oracle.com
2021-04-26Merge tag 'x86-apic-2021-04-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic update from Thomas Gleixner: "A single commit to make the vector allocation code more resilent against an accidental allocation attempt for IRQ2" * tag 'x86-apic-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vector: Add a sanity check to prevent IRQ2 allocations
2021-04-26Merge tag 'x86_platform_for_v5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Borislav Petkov: "A bunch of SGI UV improvements, fixes and cleanups" * tag 'x86_platform_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Remove dead !CONFIG_KEXEC_CORE code x86/platform/uv: Fix !KEXEC build failure x86/platform/uv: Add more to secondary CPU kdump info x86/platform/uv: Use x2apic enabled bit as set by BIOS to indicate APIC mode x86/platform/uv: Set section block size for hubless architectures x86/platform/uv: Fix indentation warning in Documentation/ABI/testing/sysfs-firmware-sgi_uv
2021-04-16x86/platform/uv: Use x2apic enabled bit as set by BIOS to indicate APIC modeMike Travis
BIOS now sets the x2apic enabled bit (and the ACPI table) for extended APIC modes. Use that bit to indicate if extended mode is set. [ bp: Fixup subject prefix, merge subsequent fix https://lkml.kernel.org/r/20210415220626.223955-1-mike.travis@hpe.com ] Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210408160047.1703-1-mike.travis@hpe.com
2021-03-30x86/vector: Add a sanity check to prevent IRQ2 allocationsThomas Gleixner
To prevent another incidental removal of the IRQ2 ignore logic in the IO/APIC code going unnoticed add a sanity check. Add some commentry at the other place which ignores IRQ2 while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210318192819.795280387@linutronix.de
2021-03-21Merge branch 'linus' into x86/cleanups, to resolve conflictIngo Molnar
Conflicts: arch/x86/kernel/kprobes/ftrace.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-03-19x86/apic/of: Fix CPU devicetree-node lookupsJohan Hovold
Architectures that describe the CPU topology in devicetree and do not have an identity mapping between physical and logical CPU ids must override the default implementation of arch_match_cpu_phys_id(). Failing to do so breaks CPU devicetree-node lookups using of_get_cpu_node() and of_cpu_device_node_get() which several drivers rely on. It also causes the CPU struct devices exported through sysfs to point to the wrong devicetree nodes. On x86, CPUs are described in devicetree using their APIC ids and those do not generally coincide with the logical ids, even if CPU0 typically uses APIC id 0. Add the missing implementation of arch_match_cpu_phys_id() so that CPU-node lookups work also with SMP. Apart from fixing the broken sysfs devicetree-node links this likely does not affect current users of mainline kernels on x86. Fixes: 4e07db9c8db8 ("x86/devicetree: Use CPU description from Device Tree") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210312092033.26317-1-johan@kernel.org
2021-03-19x86/ioapic: Ignore IRQ2 againThomas Gleixner
Vitaly ran into an issue with hotplugging CPU0 on an Amazon instance where the matrix allocator claimed to be out of vectors. He analyzed it down to the point that IRQ2, the PIC cascade interrupt, which is supposed to be not ever routed to the IO/APIC ended up having an interrupt vector assigned which got moved during unplug of CPU0. The underlying issue is that IRQ2 for various reasons (see commit af174783b925 ("x86: I/O APIC: Never configure IRQ2" for details) is treated as a reserved system vector by the vector core code and is not accounted as a regular vector. The Amazon BIOS has an routing entry of pin2 to IRQ2 which causes the IO/APIC setup to claim that interrupt which is granted by the vector domain because there is no sanity check. As a consequence the allocation counter of CPU0 underflows which causes a subsequent unplug to fail with: [ ... ] CPU 0 has 4294967295 vectors, 589 available. Cannot disable CPU There is another sanity check missing in the matrix allocator, but the underlying root cause is that the IO/APIC code lost the IRQ2 ignore logic during the conversion to irqdomains. For almost 6 years nobody complained about this wreckage, which might indicate that this requirement could be lifted, but for any system which actually has a PIC IRQ2 is unusable by design so any routing entry has no effect and the interrupt cannot be connected to a device anyway. Due to that and due to history biased paranoia reasons restore the IRQ2 ignore logic and treat it as non existent despite a routing entry claiming otherwise. Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210318192819.636943062@linutronix.de
2021-03-18x86: Fix various typos in commentsIngo Molnar
Fix ~144 single-word typos in arch/x86/ code comments. Doing this in a single commit should reduce the churn. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org
2021-03-08x86/platform/uv: Set section block size for hubless architecturesMike Travis
Commit bbbd2b51a2aa ("x86/platform/UV: Use new set memory block size function") added a call to set the block size value that is needed by the kernel to set the boundaries in the section list. This was done for UV Hubbed systems but missed in the UV Hubless setup. Fix that mistake by adding that same set call for hubless systems, which support the same NVRAMs and Intel BIOS, thus the same problem occurs. [ bp: Massage commit message. ] Fixes: bbbd2b51a2aa ("x86/platform/UV: Use new set memory block size function") Signed-off-by: Mike Travis <mike.travis@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Steve Wahl <steve.wahl@hpe.com> Reviewed-by: Russ Anderson <rja@hpe.com> Link: https://lkml.kernel.org/r/20210305162853.299892-1-mike.travis@hpe.com
2021-02-24Merge tag 'x86-entry-2021-02-24' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq entry updates from Thomas Gleixner: "The irq stack switching was moved out of the ASM entry code in course of the entry code consolidation. It ended up being suboptimal in various ways. This reworks the X86 irq stack handling: - Make the stack switching inline so the stackpointer manipulation is not longer at an easy to find place. - Get rid of the unnecessary indirect call. - Avoid the double stack switching in interrupt return and reuse the interrupt stack for softirq handling. - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused about the stack pointer manipulation" * tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix stack-swizzle for FRAME_POINTER=y um: Enforce the usage of asm-generic/softirq_stack.h x86/softirq/64: Inline do_softirq_own_stack() softirq: Move do_softirq_own_stack() to generic asm header softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK x86/softirq: Remove indirection in do_softirq_own_stack() x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall x86/entry: Convert device interrupts to inline stack switching x86/entry: Convert system vectors to irq stack macro x86/irq: Provide macro for inlining irq stack switching x86/apic: Split out spurious handling code x86/irq/64: Adjust the per CPU irq stack pointer by 8 x86/irq: Sanitize irq stack tracking x86/entry: Fix instrumentation annotation
2021-02-24Merge tag 'sfi-removal-5.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull Simple Firmware Interface (SFI) support removal from Rafael Wysocki: "Drop support for depercated platforms using SFI, drop the entire support for SFI that has been long deprecated too and make some janitorial changes on top of that (Andy Shevchenko)" * tag 'sfi-removal-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: x86/platform/intel-mid: Update Copyright year and drop file names x86/platform/intel-mid: Remove unused header inclusion in intel-mid.h x86/platform/intel-mid: Drop unused __intel_mid_cpu_chip and Co. x86/platform/intel-mid: Get rid of intel_scu_ipc_legacy.h x86/PCI: Describe @reg for type1_access_ok() x86/PCI: Get rid of custom x86 model comparison sfi: Remove framework for deprecated firmware cpufreq: sfi-cpufreq: Remove driver for deprecated firmware media: atomisp: Remove unused header mfd: intel_msic: Remove driver for deprecated platform x86/apb_timer: Remove driver for deprecated platform x86/platform/intel-mid: Remove unused leftovers (vRTC) x86/platform/intel-mid: Remove unused leftovers (msic) x86/platform/intel-mid: Remove unused leftovers (msic_thermal) x86/platform/intel-mid: Remove unused leftovers (msic_power_btn) x86/platform/intel-mid: Remove unused leftovers (msic_gpio) x86/platform/intel-mid: Remove unused leftovers (msic_battery) x86/platform/intel-mid: Remove unused leftovers (msic_ocd) x86/platform/intel-mid: Remove unused leftovers (msic_audio) platform/x86: intel_scu_wdt: Drop mistakenly added const
2021-02-21Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "x86: - Support for userspace to emulate Xen hypercalls - Raise the maximum number of user memslots - Scalability improvements for the new MMU. Instead of the complex "fast page fault" logic that is used in mmu.c, tdp_mmu.c uses an rwlock so that page faults are concurrent, but the code that can run against page faults is limited. Right now only page faults take the lock for reading; in the future this will be extended to some cases of page table destruction. I hope to switch the default MMU around 5.12-rc3 (some testing was delayed due to Chinese New Year). - Cleanups for MAXPHYADDR checks - Use static calls for vendor-specific callbacks - On AMD, use VMLOAD/VMSAVE to save and restore host state - Stop using deprecated jump label APIs - Workaround for AMD erratum that made nested virtualization unreliable - Support for LBR emulation in the guest - Support for communicating bus lock vmexits to userspace - Add support for SEV attestation command - Miscellaneous cleanups PPC: - Support for second data watchpoint on POWER10 - Remove some complex workarounds for buggy early versions of POWER9 - Guest entry/exit fixes ARM64: - Make the nVHE EL2 object relocatable - Cleanups for concurrent translation faults hitting the same page - Support for the standard TRNG hypervisor call - A bunch of small PMU/Debug fixes - Simplification of the early init hypercall handling Non-KVM changes (with acks): - Detection of contended rwlocks (implemented only for qrwlocks, because KVM only needs it for x86) - Allow __DISABLE_EXPORTS from assembly code - Provide a saner follow_pfn replacements for modules" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (192 commits) KVM: x86/xen: Explicitly pad struct compat_vcpu_info to 64 bytes KVM: selftests: Don't bother mapping GVA for Xen shinfo test KVM: selftests: Fix hex vs. decimal snafu in Xen test KVM: selftests: Fix size of memslots created by Xen tests KVM: selftests: Ignore recently added Xen tests' build output KVM: selftests: Add missing header file needed by xAPIC IPI tests KVM: selftests: Add operand to vmsave/vmload/vmrun in svm.c KVM: SVM: Make symbol 'svm_gp_erratum_intercept' static locking/arch: Move qrwlock.h include after qspinlock.h KVM: PPC: Book3S HV: Fix host radix SLB optimisation with hash guests KVM: PPC: Book3S HV: Ensure radix guest has no SLB entries KVM: PPC: Don't always report hash MMU capability for P9 < DD2.2 KVM: PPC: Book3S HV: Save and restore FSCR in the P9 path KVM: PPC: remove unneeded semicolon KVM: PPC: Book3S HV: Use POWER9 SLBIA IH=6 variant to clear SLB KVM: PPC: Book3S HV: No need to clear radix host SLB before loading HPT guest KVM: PPC: Book3S HV: Fix radix guest SLB side channel KVM: PPC: Book3S HV: Remove support for running HPT guest on RPT host without mixed mode support KVM: PPC: Book3S HV: Introduce new capability for 2nd DAWR KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWR ...
2021-02-15sfi: Remove framework for deprecated firmwareAndy Shevchenko
SFI-based platforms are gone. So does this framework. This removes mention of SFI through the drivers and other code as well. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-02-12Merge branch 'x86/paravirt' into x86/entryIngo Molnar
Merge in the recent paravirt changes to resolve conflicts caused by objtool annotations. Conflicts: arch/x86/xen/xen-asm.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-02-10x86/apic: Split out spurious handling codeThomas Gleixner
sysvec_spurious_apic_interrupt() calls into the handling body of __spurious_interrupt() which is not obvious as that function is declared inside the DEFINE_IDTENTRY_IRQ(spurious_interrupt) macro. As __spurious_interrupt() is currently always inlined this ends up with two copies of the same code for no reason. Split the handling function out and invoke it from both entry points. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002512.469379641@linutronix.de
2021-02-04x86/apic: Add extra serialization for non-serializing MSRsDave Hansen
Jan Kiszka reported that the x2apic_wrmsr_fence() function uses a plain MFENCE while the Intel SDM (10.12.3 MSR Access in x2APIC Mode) calls for MFENCE; LFENCE. Short summary: we have special MSRs that have weaker ordering than all the rest. Add fencing consistent with current SDM recommendations. This is not known to cause any issues in practice, only in theory. Longer story below: The reason the kernel uses a different semantic is that the SDM changed (roughly in late 2017). The SDM changed because folks at Intel were auditing all of the recommended fences in the SDM and realized that the x2apic fences were insufficient. Why was the pain MFENCE judged insufficient? WRMSR itself is normally a serializing instruction. No fences are needed because the instruction itself serializes everything. But, there are explicit exceptions for this serializing behavior written into the WRMSR instruction documentation for two classes of MSRs: IA32_TSC_DEADLINE and the X2APIC MSRs. Back to x2apic: WRMSR is *not* serializing in this specific case. But why is MFENCE insufficient? MFENCE makes writes visible, but only affects load/store instructions. WRMSR is unfortunately not a load/store instruction and is unaffected by MFENCE. This means that a non-serializing WRMSR could be reordered by the CPU to execute before the writes made visible by the MFENCE have even occurred in the first place. This means that an x2apic IPI could theoretically be triggered before there is any (visible) data to process. Does this affect anything in practice? I honestly don't know. It seems quite possible that by the time an interrupt gets to consume the (not yet) MFENCE'd data, it has become visible, mostly by accident. To be safe, add the SDM-recommended fences for all x2apic WRMSRs. This also leaves open the question of the _other_ weakly-ordered WRMSR: MSR_IA32_TSC_DEADLINE. While it has the same ordering architecture as the x2APIC MSRs, it seems substantially less likely to be a problem in practice. While writes to the in-memory Local Vector Table (LVT) might theoretically be reordered with respect to a weakly-ordered WRMSR like TSC_DEADLINE, the SDM has this to say: In x2APIC mode, the WRMSR instruction is used to write to the LVT entry. The processor ensures the ordering of this write and any subsequent WRMSR to the deadline; no fencing is required. But, that might still leave xAPIC exposed. The safest thing to do for now is to add the extra, recommended LFENCE. [ bp: Massage commit message, fix typos, drop accidentally added newline to tools/arch/x86/include/asm/barrier.h. ] Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200305174708.F77040DD@viggo.jf.intel.com
2021-02-04x86/apic: Export x2apic_mode for use by KVM in "warm" pathSean Christopherson
Export x2apic_mode so that KVM can query whether x2APIC is active without having to incur the RDMSR in x2apic_enabled(). When Posted Interrupts are in use for a guest with an assigned device, KVM ends up checking for x2APIC at least once every time a vCPU halts. KVM could obviously snapshot x2apic_enabled() to avoid the RDMSR, but that's rather silly given that x2apic_mode holds the exact info needed by KVM. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210115220354.434807-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-14Merge tag 'x86-apic-2020-12-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Thomas Gleixner: "Yet another large set of x86 interrupt management updates: - Simplification and distangling of the MSI related functionality - Let IO/APIC construct the RTE entries from an MSI message instead of having IO/APIC specific code in the interrupt remapping drivers - Make the retrieval of the parent interrupt domain (vector or remap unit) less hardcoded and use the relevant irqdomain callbacks for selection. - Allow the handling of more than 255 CPUs without a virtualized IOMMU when the hypervisor supports it. This has made been possible by the above modifications and also simplifies the existing workaround in the HyperV specific virtual IOMMU. - Cleanup of the historical timer_works() irq flags related inconsistencies" * tag 'x86-apic-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/ioapic: Cleanup the timer_works() irqflags mess iommu/hyper-v: Remove I/O-APIC ID check from hyperv_irq_remapping_select() iommu/amd: Fix IOMMU interrupt generation in X2APIC mode iommu/amd: Don't register interrupt remapping irqdomain when IR is disabled iommu/amd: Fix union of bitfields in intcapxt support x86/ioapic: Correct the PCI/ISA trigger type selection x86/ioapic: Use I/O-APIC ID for finding irqdomain, not index x86/hyperv: Enable 15-bit APIC ID if the hypervisor supports it x86/kvm: Enable 15-bit extension when KVM_FEATURE_MSI_EXT_DEST_ID detected iommu/hyper-v: Disable IRQ pseudo-remapping if 15 bit APIC IDs are available x86/apic: Support 15 bits of APIC ID in MSI where available x86/ioapic: Handle Extended Destination ID field in RTE iommu/vt-d: Simplify intel_irq_remapping_select() x86: Kill all traces of irq_remapping_get_irq_domain() x86/ioapic: Use irq_find_matching_fwspec() to find remapping irqdomain x86/hpet: Use irq_find_matching_fwspec() to find remapping irqdomain iommu/hyper-v: Implement select() method on remapping irqdomain iommu/vt-d: Implement select() method on remapping irqdomain iommu/amd: Implement select() method on remapping irqdomain x86/apic: Add select() method on vector irqdomain ...
2020-12-14Merge tag 'x86_platform_for_v5.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Borislav Petkov: - add a new uv_sysfs driver and expose read-only information from UV BIOS (Justin Ernst and Mike Travis) - the usual set of small fixes * tag 'x86_platform_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Update sysfs documentation x86/platform/uv: Add deprecated messages to /proc info leaves x86/platform/uv: Add sysfs hubless leaves x86/platform/uv: Add sysfs leaves to replace those in procfs x86/platform/uv: Add kernel interfaces for obtaining system info x86/platform/uv: Make uv_pcibus_kset and uv_hubs_kset static x86/platform/uv: Fix an error code in uv_hubs_init() x86/platform/uv: Update MAINTAINERS for uv_sysfs driver x86/platform/uv: Update ABI documentation of /sys/firmware/sgi_uv/ x86/platform/uv: Add new uv_sysfs platform driver x86/platform/uv: Add and export uv_bios_* functions x86/platform/uv: Remove existing /sys/firmware/sgi_uv/ interface
2020-12-10x86/ioapic: Cleanup the timer_works() irqflags messThomas Gleixner
Mark tripped over the creative irqflags handling in the IO-APIC timer delivery check which ends up doing: local_irq_save(flags); local_irq_enable(); local_irq_restore(flags); which triggered a new consistency check he's working on required for replacing the POPF based restore with a conditional STI. That code is a historical mess and none of this is needed. Make it straightforward use local_irq_disable()/enable() as that's all what is required. It is invoked from interrupt enabled code nowadays. Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/87k0tpju47.fsf@nanos.tec.linutronix.de
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