linux.git/arch/x86/hyperv, branch v6.17

x86/hyperv: Expose hv_map_msi_interrupt()

2025-07-15T06:24:16+00:00

Move some of the logic of hv_irq_compose_irq_message() into
hv_map_msi_interrupt(). Make hv_map_msi_interrupt() a globally-available
helper function, which will be used to map PCI interrupts when running
in the root partition.

Signed-off-by: Stanislav Kinsburskii 
Signed-off-by: Nuno Das Neves 
Reviewed-by: Roman Kisel 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/1752261532-7225-3-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <1752261532-7225-3-git-send-email-nunodasneves@linux.microsoft.com>

x86/hyperv: Clean up hv_map/unmap_interrupt() return values

2025-07-09T23:49:25+00:00

Fix the return values of these hypercall helpers so they return
a negated errno either directly or via hv_result_to_errno().

Update the callers to check for errno instead of using
hv_status_success(), and remove redundant error printing.

While at it, rearrange some variable declarations to adhere to style
guidelines i.e. "reverse fir tree order".

Signed-off-by: Nuno Das Neves 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/1751582677-30930-5-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <1751582677-30930-5-git-send-email-nunodasneves@linux.microsoft.com>

x86/hyperv: Fix usage of cpu_online_mask to get valid cpu

2025-07-09T23:49:25+00:00

Accessing cpu_online_mask here is problematic because the cpus read lock
is not held in this context.

However, cpu_online_mask isn't needed here since the effective affinity
mask is guaranteed to be valid in this callback. So, just use
cpumask_first() to get the cpu instead of ANDing it with cpus_online_mask
unnecessarily.

Fixes: e39397d1fd68 ("x86/hyperv: implement an MSI domain for root partition")
Reported-by: Michael Kelley 
Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB4157639630F8AD2D8FD8F52FD475A@SN6PR02MB4157.namprd02.prod.outlook.com/
Suggested-by: Thomas Gleixner 
Signed-off-by: Nuno Das Neves 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com>

x86/hyperv: Fix warnings for missing export.h header inclusion

2025-07-09T23:43:53+00:00

Fix below warning in Hyper-V drivers that comes when kernel is compiled
with W=1 option. Include export.h in driver files to fix it.
* warning: EXPORT_SYMBOL() is used, but #include 
is missing

Signed-off-by: Naman Jain 
Reviewed-by: Saurabh Sengar 
Link: https://lore.kernel.org/r/20250611100459.92900-3-namjain@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20250611100459.92900-3-namjain@linux.microsoft.com>

Merge tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2025-06-03T15:39:20+00:00

Pull hyperv updates from Wei Liu:

 - Support for Virtual Trust Level (VTL) on arm64 (Roman Kisel)

 - Fixes for Hyper-V UIO driver (Long Li)

 - Fixes for Hyper-V PCI driver (Michael Kelley)

 - Select CONFIG_SYSFB for Hyper-V guests (Michael Kelley)

 - Documentation updates for Hyper-V VMBus (Michael Kelley)

 - Enhance logging for hv_kvp_daemon (Shradha Gupta)

* tag 'hyperv-next-signed-20250602' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (23 commits)
  Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests
  Drivers: hv: vmbus: Add comments about races with "channels" sysfs dir
  Documentation: hyperv: Update VMBus doc with new features and info
  PCI: hv: Remove unnecessary flex array in struct pci_packet
  Drivers: hv: Remove hv_alloc/free_* helpers
  Drivers: hv: Use kzalloc for panic page allocation
  uio_hv_generic: Align ring size to system page
  uio_hv_generic: Use correct size for interrupt and monitor pages
  Drivers: hv: Allocate interrupt and monitor pages aligned to system page boundary
  arch/x86: Provide the CPU number in the wakeup AP callback
  x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()
  PCI: hv: Get vPCI MSI IRQ domain from DeviceTree
  ACPI: irq: Introduce acpi_get_gsi_dispatcher()
  Drivers: hv: vmbus: Introduce hv_get_vmbus_root_device()
  Drivers: hv: vmbus: Get the IRQ number from DeviceTree
  dt-bindings: microsoft,vmbus: Add interrupt and DMA coherence properties
  arm64, x86: hyperv: Report the VTL the system boots in
  arm64: hyperv: Initialize the Virtual Trust Level field
  Drivers: hv: Provide arch-neutral implementation of get_vtl()
  Drivers: hv: Enable VTL mode for arm64
  ...

arch/x86: Provide the CPU number in the wakeup AP callback

2025-05-23T16:30:56+00:00

When starting APs, confidential guests and paravisor guests
need to know the CPU number, and the pattern of using the linear
search has emerged in several places. With N processors that leads
to the O(N^2) time complexity.

Provide the CPU number in the AP wake up callback so that one can
get the CPU number in constant time.

Suggested-by: Michael Kelley 
Signed-off-by: Roman Kisel 
Reviewed-by: Tom Lendacky 
Reviewed-by: Thomas Gleixner 
Reviewed-by: Michael Kelley 
Acked-by: Rafael J. Wysocki 
Link: https://lore.kernel.org/r/20250507182227.7421-3-romank@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20250507182227.7421-3-romank@linux.microsoft.com>

x86/hyperv: Fix APIC ID and VP index confusion in hv_snp_boot_ap()

2025-05-23T16:30:56+00:00

To start an application processor in SNP-isolated guest, a hypercall
is used that takes a virtual processor index. The hv_snp_boot_ap()
function uses that START_VP hypercall but passes as VP index to it
what it receives as a wakeup_secondary_cpu_64 callback: the APIC ID.

As those two aren't generally interchangeable, that may lead to hung
APs if the VP index and the APIC ID don't match up.

Update the parameter names to avoid confusion as to what the parameter
is. Use the APIC ID to the VP index conversion to provide the correct
input to the hypercall.

Cc: stable@vger.kernel.org
Fixes: 44676bb9d566 ("x86/hyperv: Add smp support for SEV-SNP guest")
Signed-off-by: Roman Kisel 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20250507182227.7421-2-romank@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20250507182227.7421-2-romank@linux.microsoft.com>

arm64, x86: hyperv: Report the VTL the system boots in

2025-05-23T16:30:55+00:00

The hyperv guest code might run in various Virtual Trust Levels.

Report the level when the kernel boots in the non-default (0)
one.

Signed-off-by: Roman Kisel 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20250428210742.435282-7-romank@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20250428210742.435282-7-romank@linux.microsoft.com>

Drivers: hv: Provide arch-neutral implementation of get_vtl()

2025-05-23T16:30:55+00:00

To run in the VTL mode, Hyper-V drivers have to know what
VTL the system boots in, and the arm64/hyperv code does not
have the means to compute that.

Refactor the code to hoist the function that detects VTL,
make it arch-neutral to be able to employ it to get the VTL
on arm64.

Signed-off-by: Roman Kisel 
Reviewed-by: Michael Kelley 
Reviewed-by: Tianyu Lan 
Link: https://lore.kernel.org/r/20250428210742.435282-5-romank@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20250428210742.435282-5-romank@linux.microsoft.com>

x86/msr: Replace wrmsr(msr, low, 0) with wrmsrq(msr, low)

2025-05-02T08:36:36+00:00

The third argument in wrmsr(msr, low, 0) is unnecessary.  Instead, use
wrmsrq(msr, low), which automatically sets the higher 32 bits of the
MSR value to 0.

Signed-off-by: Xin Li (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Brian Gerst 
Cc: David Woodhouse 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Paolo Bonzini 
Cc: Sean Christopherson 
Cc: Stefano Stabellini 
Cc: Uros Bizjak 
Cc: Vitaly Kuznetsov 
Link: https://lore.kernel.org/r/20250427092027.1598740-15-xin@zytor.com