Pull Hyper-V updates from Wei Liu:
- Debugfs support for MSHV statistics (Nuno Das Neves)
- Support for the integrated scheduler (Stanislav Kinsburskii)
- Various fixes for MSHV memory management and hypervisor status
handling (Stanislav Kinsburskii)
- Expose more capabilities and flags for MSHV partition management
(Anatol Belski, Muminul Islam, Magnus Kulke)
- Miscellaneous fixes to improve code quality and stability (Carlos
López, Ethan Nelson-Moore, Li RongQing, Michael Kelley, Mukesh
Rathor, Purna Pavan Chandra Aekkaladevi, Stanislav Kinsburskii, Uros
Bizjak)
- PREEMPT_RT fixes for vmbus interrupts (Jan Kiszka)
* tag 'hyperv-next-signed-20260218' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (34 commits)
mshv: Handle insufficient root memory hypervisor statuses
mshv: Handle insufficient contiguous memory hypervisor status
mshv: Introduce hv_deposit_memory helper functions
mshv: Introduce hv_result_needs_memory() helper function
mshv: Add SMT_ENABLED_GUEST partition creation flag
mshv: Add nested virtualization creation flag
Drivers: hv: vmbus: Simplify allocation of vmbus_evt
mshv: expose the scrub partition hypercall
mshv: Add support for integrated scheduler
mshv: Use try_cmpxchg() instead of cmpxchg()
x86/hyperv: Fix error pointer dereference
x86/hyperv: Reserve 3 interrupt vectors used exclusively by MSHV
Drivers: hv: vmbus: Use kthread for vmbus interrupts on PREEMPT_RT
x86/hyperv: Remove ASM_CALL_CONSTRAINT with VMMCALL insn
x86/hyperv: Use savesegment() instead of inline asm() to save segment registers
mshv: fix SRCU protection in irqfd resampler ack handler
mshv: make field names descriptive in a header struct
x86/hyperv: Update comment in hyperv_cleanup()
mshv: clear eventfd counter on irqfd shutdown
x86/hyperv: Use memremap()/memunmap() instead of ioremap_cache()/iounmap()
...
When creating guest partition objects, the hypervisor may fail to
allocate root partition pages and return an insufficient memory status.
In this case, deposit memory using the root partition ID instead.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Mukesh R <mrathor@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The HV_STATUS_INSUFFICIENT_CONTIGUOUS_MEMORY status indicates that the
hypervisor lacks sufficient contiguous memory for its internal allocations.
When this status is encountered, allocate and deposit
HV_MAX_CONTIGUOUS_ALLOCATION_PAGES contiguous pages to the hypervisor.
HV_MAX_CONTIGUOUS_ALLOCATION_PAGES is defined in the hypervisor headers, a
deposit of this size will always satisfy the hypervisor's requirements.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Mukesh R <mrathor@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Add support for HV_PARTITION_CREATION_FLAG_SMT_ENABLED_GUEST
to allow userspace VMMs to enable SMT for guest partitions.
Expose this via new MSHV_PT_BIT_SMT_ENABLED_GUEST flag in the UAPI.
Without this flag, the hypervisor schedules guest VPs incorrectly,
causing SMT unusable.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Introduce HV_PARTITION_CREATION_FLAG_NESTED_VIRTUALIZATION_CAPABLE to
indicate support for nested virtualization during partition creation.
This enables clearer configuration and capability checks for nested
virtualization scenarios.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This hypercall needs to be exposed for VMMs to soft-reboot guests. It
will reset APIC and synthetic interrupt controller state, among others.
Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Query the hypervisor for integrated scheduler support and use it if
configured.
Microsoft Hypervisor originally provided two schedulers: root and core. The
root scheduler allows the root partition to schedule guest vCPUs across
physical cores, supporting both time slicing and CPU affinity (e.g., via
cgroups). In contrast, the core scheduler delegates vCPU-to-physical-core
scheduling entirely to the hypervisor.
Direct virtualization introduces a new privileged guest partition type - L1
Virtual Host (L1VH) — which can create child partitions from its own
resources. These child partitions are effectively siblings, scheduled by
the hypervisor's core scheduler. This prevents the L1VH parent from setting
affinity or time slicing for its own processes or guest VPs. While cgroups,
CFS, and cpuset controllers can still be used, their effectiveness is
unpredictable, as the core scheduler swaps vCPUs according to its own logic
(typically round-robin across all allocated physical CPUs). As a result,
the system may appear to "steal" time from the L1VH and its children.
To address this, Microsoft Hypervisor introduces the integrated scheduler.
This allows an L1VH partition to schedule its own vCPUs and those of its
guests across its "physical" cores, effectively emulating root scheduler
behavior within the L1VH, while retaining core scheduler behavior for the
rest of the system.
The integrated scheduler is controlled by the root partition and gated by
the vmm_enable_integrated_scheduler capability bit. If set, the hypervisor
supports the integrated scheduler. The L1VH partition must then check if it
is enabled by querying the corresponding extended partition property. If
this property is true, the L1VH partition must use the root scheduler
logic; otherwise, it must use the core scheduler. This requirement makes
reading VMM capabilities in L1VH partition a requirement too.
Signed-off-by: Andreea Pintilie <anpintil@microsoft.com>
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
KVM SVM changes for 6.20
- Drop a user-triggerable WARN on nested_svm_load_cr3() failure.
- Add support for virtualizing ERAPS. Note, correct virtualization of ERAPS
relies on an upcoming, publicly announced change in the APM to reduce the
set of conditions where hardware (i.e. KVM) *must* flush the RAP.
- Ignore nSVM intercepts for instructions that are not supported according to
L1's virtual CPU model.
- Add support for expedited writes to the fast MMIO bus, a la VMX's fastpath
for EPT Misconfig.
- Don't set GIF when clearing EFER.SVME, as GIF exists independently of SVM,
and allow userspace to restore nested state with GIF=0.
- Treat exit_code as an unsigned 64-bit value through all of KVM.
- Add support for fetching SNP certificates from userspace.
- Fix a bug where KVM would use vmcb02 instead of vmcb01 when emulating VMLOAD
or VMSAVE on behalf of L2.
- Misc fixes and cleanups.
hv_stats_page belongs in hvhdk.h, move it there.
It does not require a union to access the data for different counters,
just use a single u64 array for simplicity and to match the Windows
definitions.
While at it, correct the ARM64 value for VpRootDispatchThreadBlocked.
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Fix KVM's long-standing buggy handling of SVM's exit_code as a 32-bit
value. Per the APM and Xen commit d1bd157fbc ("Big merge the HVM
full-virtualisation abstractions.") (which is arguably more trustworthy
than KVM), offset 0x70 is a single 64-bit value:
070h 63:0 EXITCODE
Track exit_code as a single u64 to prevent reintroducing bugs where KVM
neglects to correctly set bits 63:32.
Fixes: 6aa8b732ca ("[PATCH] kvm: userspace interface")
Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Use the new __TRAILING_OVERLAP() helper to fix the following warning:
include/hyperv/hvgdk_mini.h:581:25: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
This helper creates a union between a flexible-array member (FAM) and a
set of MEMBERS that would otherwise follow it.
This overlays the trailing MEMBER u64 gva_list[]; onto the FAM
struct hv_tlb_flush_ex::hv_vp_set.bank_contents[], while keeping
the FAM and the start of MEMBER aligned.
The static_assert() ensures this alignment remains, and it's
intentionally placed inmediately after the related structure --no
blank line in between.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Interrupt control structure (union hv_interupt_control) has different
fields when it comes to x86 vs ARM64. Bring in the correct structure
from HyperV header files and adjust the existing interrupt routing
code accordingly.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 <romank@linux.microsoft.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Add data structures for hypervisor crash dump support to the hypervisor
host ABI header file. Details of their usages are in subsequent commits.
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
In preparation for the subsequent crashdump patches, copy two hypercall
numbers to the guest ABI header published by Hyper-V. One to notify
hypervisor of an event that occurs in the root partition, other to ask
hypervisor to disable the hypervisor.
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Introduce HVCALL_MAP_STATS_PAGE2 which provides a map location (GPFN)
to map the stats to. This hypercall is required for L1VH partitions,
depending on the hypervisor version. This uses the same check as the
state page map location; mshv_use_overlay_gpfn().
Add mshv_map_vp_state_page() helpers to use this new hypercall or the
old one depending on availability.
For unmapping, the original HVCALL_UNMAP_STATS_PAGE works for both
cases.
Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The file contains a line that consists of the lone # symbol
followed by a newline. While that is a valid syntax as
defined by the C99+ grammar (6.10.7 "Null directive"), it
serves no apparent purpose in this case.
Remove the null preprocessor directive. No functional changes.
Fixes: e68bda71a2 ("hyperv: Add new Hyper-V headers in include/hyperv")
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This field is unused, but the correct structure size is needed
when computing the amount of space for the output argument to
reside, so that it does not cross a page boundary.
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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
...
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: 44676bb9d5 ("x86/hyperv: Add smp support for SEV-SNP guest")
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250507182227.7421-2-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250507182227.7421-2-romank@linux.microsoft.com>
Current code varies in how the size of the variable size input header
for hypercalls is calculated when the input contains struct hv_vpset.
Surprisingly, this variation is correct, as different hypercalls make
different choices for what portion of struct hv_vpset is treated as part
of the variable size input header. The Hyper-V TLFS is silent on these
details, but the behavior has been confirmed with Hyper-V developers.
To avoid future confusion about these differences, add comments to
struct hv_vpset, and to hypercall call sites with input that contains
a struct hv_vpset. The comments describe the overall situation and
the calculation that should be used at each particular call site.
No functional change as only comments are updated.
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250318214919.958953-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250318214919.958953-1-mhklinux@outlook.com>
These headers contain definitions for regular Hyper-V guests (as in
hyperv-tlfs.h), as well as interfaces for more privileged guests like
the root partition (aka Dom0).
These files are derived from headers exported from Hyper-V, rather than
being derived from the TLFS document. (Although, to preserve
compatibility with existing Linux code, some definitions are copied
directly from hyperv-tlfs.h too).
The new files follow a naming convention according to their original
use:
- hdk "host development kit"
- gdk "guest development kit"
With postfix "_mini" implying userspace-only headers, and "_ext" for
extended hypercalls.
The use of multiple files and their original names is primarily to
keep the provenance of exactly where they came from in Hyper-V
code, which is helpful for manual maintenance and extension
of these definitions. Microsoft maintainers importing new definitions
should take care to put them in the right file. However, Linux kernel
code that uses any of the definitions need not be aware of the multiple
files or assign any meaning to the new names. Linux kernel code should
always just include hvhdk.h
Note the new headers contain both arm64 and x86_64 definitions. Some are
guarded by #ifdefs, and some are instead prefixed with the architecture,
e.g. hv_x64_*. These conventions are kept from Hyper-V code as another
tactic to simplify the process of importing and maintaining the
definitions, rather than splitting them up into their own files in
arch/x86/ and arch/arm64/.
These headers are a step toward importing headers directly from Hyper-V
in the future, similar to Xen public files in include/xen/interface/.
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Link: https://lore.kernel.org/r/1732577084-2122-4-git-send-email-nunodasneves@linux.microsoft.com
Link: https://lore.kernel.org/r/20250108222138.1623703-2-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
