kernel/arch/x86/include/asm/mshyperv.h, branch linux-rolling-stable

mshv: Cleanly shutdown root partition with MSHV

2025-12-05T23:25:05Z

Root partitions running on MSHV currently attempt ACPI power-off, which MSHV intercepts and triggers a Machine Check Exception (MCE), leading to a kernel panic. Root partitions panic with a trace similar to: [ 81.306348] reboot: Power down [ 81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001 [ 81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9 [ 81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff [ 81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii' [ 81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt [ 81.314717] Kernel panic - not syncing: Fatal machine check To avoid this, configure the sleep state in the hypervisor and invoke the HVCALL_ENTER_SLEEP_STATE hypercall as the final step in the shutdown sequence. This ensures a clean and safe shutdown of the root partition. Signed-off-by: Praveen K Paladugu Co-developed-by: Anatol Belski Signed-off-by: Anatol Belski Reviewed-by: Easwar Hariharan Acked-by: Stanislav Kinsburskii Signed-off-by: Wei Liu

mshv: Use reboot notifier to configure sleep state

2025-12-05T23:25:01Z

Configure sleep state information from ACPI in MSHV hypervisor using a reboot notifier. This data allows the hypervisor to correctly power off the host during shutdown. Signed-off-by: Praveen K Paladugu Co-developed-by: Anatol Belski Signed-off-by: Anatol Belski Reviewed-by: Easwar Hariharan Reviewed-by: Stansialv Kinsburskii Acked-by: Ingo Molnar Reviewed-by: Nuno Das Neves Signed-off-by: Wei Liu

Drivers: hv: Introduce mshv_vtl driver

2025-12-05T23:16:26Z

Provide an interface for Virtual Machine Monitor like OpenVMM and its use as OpenHCL paravisor to control VTL0 (Virtual trust Level). Expose devices and support IOCTLs for features like VTL creation, VTL0 memory management, context switch, making hypercalls, mapping VTL0 address space to VTL2 userspace, getting new VMBus messages and channel events in VTL2 etc. Co-developed-by: Roman Kisel Signed-off-by: Roman Kisel Co-developed-by: Saurabh Sengar Signed-off-by: Saurabh Sengar Reviewed-by: Michael Kelley Signed-off-by: Naman Jain Signed-off-by: Wei Liu

x86/hyperv: Enable build of hypervisor crashdump collection files

2025-11-15T06:18:16Z

Enable build of the new files introduced in the earlier commits and add call to do the setup during boot. Signed-off-by: Mukesh Rathor [ wei: fix build ] Signed-off-by: Wei Liu

x86/hyperv: Clean up hv_do_hypercall()

2025-08-18T12:23:07Z

What used to be a simple few instructions has turned into a giant mess (for x86_64). Not only does it use static_branch wrong, it mixes it with dynamic branches for no apparent reason. Notably it uses static_branch through an out-of-line function call, which completely defeats the purpose, since instead of a simple JMP/NOP site, you get a CALL+RET+TEST+Jcc sequence in return, which is absolutely idiotic. Add to that a dynamic test of hyperv_paravisor_present, something which is set once and never changed. Replace all this idiocy with a single direct function call to the right hypercall variant. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Michael Kelley Tested-by: Michael Kelley Acked-by: Sean Christopherson Link: https://lkml.kernel.org/r/20250714103440.897136093@infradead.org

x86/hyperv: Expose hv_map_msi_interrupt()

2025-07-15T06:24:16Z

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>

Drivers: hv: Use nested hypercall for post message and signal event

2025-07-15T06:24:16Z

When running nested, these hypercalls must be sent to the L0 hypervisor or VMBus will fail. Remove hv_do_nested_hypercall() and hv_do_fast_nested_hypercall8() altogether and open-code these cases, since there are only 2 and all they do is add the nested bit. Signed-off-by: Nuno Das Neves Reviewed-by: Roman Kisel Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com>

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

2025-06-03T15:39:20Z

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

2025-05-23T16:30:56Z

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()

2025-05-23T16:30:56Z

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>