This reverts commit 36d6cbb62133fc6eea28f380409e0fb190f3dfbe. Calling this as a passthrough hypercall leaves the VM in an inconsistent state. Revert before it is released. Signed-off-by: Wei Liu <wei.liu@kernel.org>
On x86, the HYPERVISOR_CALLBACK_VECTOR is used to receive synthetic interrupts (SINTs) from the hypervisor for doorbells and intercepts. There is no such vector reserved for arm64. On arm64, the hypervisor exposes a synthetic register that can be read to find the INTID that should be used for SINTs. This INTID is in the PPI range. To better unify the code paths, introduce mshv_sint_vector_init() that either reads the synthetic register and obtains the INTID (arm64) or just uses HYPERVISOR_CALLBACK_VECTOR as the interrupt vector (x86). Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
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.