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2026-06-24Merge tag 'kvm-s390-next-7.2-2' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD * Fix S390_USER_OPEREXEC so it can now be enabled regardless of other unrelated capabilities * Fix handling of the _PAGE_UNUSED pte bit that could lead to guest memory corruption in some scenarios * A bunch of misc gmap fixes (locking, behaviour under memory pressure) * Fix CMMA dirty tracking
2026-06-24KVM: s390: Fix typo in UCONTROL documentationEric Farman
Small typo noticed while writing the USER_OPEREXEC selftest. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260507200836.3500368-4-farman@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-06-15Merge tag 'kvm-s390-next-7.2-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: New features for 7.2 New features for 7.2 for KVM/s390: * KVM_PRE_FAULT_MEMORY support * Support for 2G hugepages * Support for the ASTFLEIE 2 facility * kvm_arch_set_irq_inatomic Fast Inject * Fix potential leak of uninitialized bytes
2026-06-12Merge tag 'kvmarm-7.2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 7.2 * New features: - None. Zilch. Nada. Que dalle. * Fixes and other improvements: - Significant cleanup of the vgic-v5 PPI support which was merged in 7.1. This makes the code more maintainable, and squashes a couple of bugs in the meantime. - Set of fixes for the handling of the MMU in an NV context, particularly VNCR-triggered faults. S1POE support is fixed as well. - Large set of pKVM fixes, mostly addressing recurring issues around hypervisor tracking of donated pages in obscure cases where the donation could fail and leave things in a bizarre state. - Fixes for the so-called "lazy vgic init", which resulted in sleeping operations in non-preemptible sections. This turned out to be far more invasive than initially expected... - Reduce the overhead of L1/L2 context switch by not touching the FP registers. - Fix the way non-implemented page sizes are dealt with when a guest insist on using them for S2 translation. - The usual set of low-impact fixes and cleanups all over the map.
2026-06-12Merge tag 'kvm-x86-svm-7.2' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM SVM changes for 7.2 - Add support for virtualizing gPAT (KVM previously just used L1's PAT when running L2). - Fix goofs where KVM mishandles side effects (e.g. single-step and PMC updates) when emulating VMRUN. - Fix a variety of bugs in AVIC's handling of x2APIC MSR interception, most notably where KVM didn't disable interception of IRR, ISR, and TMR regs. - Add support for virtualizing Host-Only/Guest-Only bits in the mediated PMU.
2026-06-12Merge tag 'kvm-x86-misc-7.2' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM misc x86 changes for 7.2 - Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor code gets a chance to handle things like reaping the PML buffer. - Ensure KVM's copy of CR0 and CR3 are up-to-date on SVM prior to invoking fastpath handlers. - Update KVM's view of PV async enabling if and only if the MSR write fully succeeds. - Fix a variety of issues where the emulator doesn't honor guest-debug state, and clean up related code along the way. - Synthesize EPT Violation and #NPF "error code" bits when injecting faults into L1 that didn't originate in hardware (in which case the VMCS/VMCB doesn't hold relevant information). - Add support for virtualizing (well, emulating) AMD's flavor of CPL>0 CPUID faulting. - Clean up the GPR APIs so that KVM's use of "raw" is consistent, and fix a variety of minor bugs along the way. - Fix an OOB memory access due to not checking the VP ID when handling a Hyper-V PV TLB flush for L2. - Fix a bug in the mediated PMU's handling of fixed counters that allowed the guest to bypass the PMU event filter. - Allow userspace to return EAGAIN when handling SNP and TDX hypercalls, so the KVM can forward a "retry" status code to the guest, and reserve all unused error codes for future usage. - Misc fixes and cleanups.
2026-06-12Merge branch kvm-arm64/vgic-v5-PPI-fixes into kvmarm-master/nextMarc Zyngier
* kvm-arm64/vgic-v5-PPI-fixes: : . : Substantial cleanup of the vgic-v5 PPI support. From the original : cover letter: : : "With the GICv5 PPi support merged in, it has become obvious that a few : things could be improved, both from the correctness and maintainability : angles." : . KVM: arm64: Fix arch timer interrupts for GICv3-on-GICv5 guests irqchip/gic-v5: Immediately exec priority drop following activate Documentation: KVM: Clarify that PMU_V3_IRQ IntID requirements for GICv5 Documentation: KVM: Fix typos in VGICv5 documentation KVM: arm64: selftests: Improve error handling for GICv5 PPI selftest KVM: arm64: selftests: Cleanup unused vars in GICv5 PPI selftest KVM: arm64: selftests: Add missing GIC CDEN to no-vgic-v5 selftest KVM: arm64: vgic-v5: Atomically assign bits to PPI DVI bitmap KVM: arm64: vgic-v5: Add missing trap handing for NV triage KVM: arm64: vgic-v5: Limit support to 64 PPIs KVM: arm64: vgic: Rationalise per-CPU irq accessor KVM: arm64: vgic-v5: Drop defensive checks from vgic_v5_ppi_queue_irq_unlock() KVM: arm64: vgic: Consolidate vgic_allocate_private_irqs_locked() KVM: arm64: vgic: Constify struct irq_ops usage KVM: arm64: vgic-v5: Drop pointless ARM64_HAS_GICV5_CPUIF check KVM: arm64: vgic-v5: Remove use of __assign_bit() with a constant KVM: arm64: vgic-v5: Move PPI caps into kvm_vgic_global_state KVM: arm64: vgic-v5: Add for_each_visible_v5_ppi() iterator Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-06-09KVM: s390: Document the KVM_CAP_S390_HPAGE_2G capabilityClaudio Imbrenda
Document the KVM_CAP_S390_HPAGE_2G capability, which behaves very similarly to the existing KVM_CAP_S390_HPAGE_1M. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260609150930.665370-5-imbrenda@linux.ibm.com>
2026-06-08Documentation: KVM: Synchronize x86 VM typesCarlos López
KVM has reflected KVM_X86_SNP_VM to userspace since 1dfe571c12cf ("KVM: SEV: Add initial SEV-SNP support"), and KVM_X86_TDX_VM since 161d34609f9b ("KVM: TDX: Make TDX VM type supported"). Update the documentation to reflect this fact. Fixes: 1dfe571c12cf ("KVM: SEV: Add initial SEV-SNP support") Fixes: 161d34609f9b ("KVM: TDX: Make TDX VM type supported") Signed-off-by: Carlos López <clopez@suse.de> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Link: https://patch.msgid.link/20260603114504.814647-2-clopez@suse.de [sean: use one tab instead of two] Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-06-03Merge branch 'kvm-ghcb-for-7.2' into HEADPaolo Bonzini
Merge the final part of the GHCB 7.2 fixes at https://lore.kernel.org/kvm/20260529183549.1104619-1-pbonzini@redhat.com/. Patches 1-17 have already been included in Linux 7.1; these are minor cleanups, and fixes for behaviors that are suboptimal or contradicting the specification. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-28KVM: s390: Update KVM_PRE_FAULT_MEMORY API documentationClaudio Imbrenda
Update the API documentation for KVM_PRE_FAULT_MEMORY to account for its s390 implementation. Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260527144358.186359-4-imbrenda@linux.ibm.com>
2026-05-27KVM: TDX: Allow userspace to return errors to guest for MAPGPAVishal Annapurve
MAPGPA request from TDX VMs gets split into chunks by KVM using a loop of userspace exits until the complete range is handled. In some cases userspace VMM might decide to break the MAPGPA operation and continue it later. For example: in the case of intrahost migration userspace might decide to continue the MAPGPA operation after the migration is completed. Allow userspace to signal to TDX guests that the MAPGPA operation should be retried the next time the guest is scheduled. This is potentially a breaking change since if userspace sets hypercall.ret to a value other than EBUSY or EINVAL an EINVAL error code will be returned to userspace. As of now QEMU never sets hypercall.ret to a non-zero value after handling KVM_EXIT_HYPERCALL so this change should be safe. Reviewed-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Vishal Annapurve <vannapurve@google.com> Co-developed-by: Sagi Shahar <sagis@google.com> Signed-off-by: Sagi Shahar <sagis@google.com> Link: https://patch.msgid.link/20260305222627.4193305-2-sagis@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-23Documentation: KVM: Clarify that PMU_V3_IRQ IntID requirements for GICv5Sascha Bischoff
When running a GICv5-based guest, the PMU must use PPI 23. This, however, must be communicated via the KVM_ARM_VCPU_PMU_V3_CTRL->KVM_ARM_VCPU_PMU_V3_IRQ ioctl as a full GICv5-style Interrupt ID. That is, 0x20000017. Optionally, the whole ioctl can be skipped for GICv5. This was previously not clearly documented, so bump the documentation accordingly. Fixes: 7c31c06e2d2d ("KVM: arm64: gic-v5: Mandate architected PPI for PMU emulation on GICv5") Link: https://sashiko.dev/#/patchset/20260319154937.3619520-1-sascha.bischoff%40arm.com Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Link: https://lore.kernel.org/r/20260520091949.542365-17-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-05-23Documentation: KVM: Fix typos in VGICv5 documentationSascha Bischoff
Fix two typos in the VGICv5 documentation. Fixes: d51c978b7d3e ("KVM: arm64: gic-v5: Communicate userspace-driveable PPIs via a UAPI") Fixes: eb3c4d2c9a4d ("Documentation: KVM: Introduce documentation for VGICv5") Link: https://sashiko.dev/#/patchset/20260319154937.3619520-1-sascha.bischoff%40arm.com Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Link: https://lore.kernel.org/r/20260520091949.542365-16-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-05-14KVM: x86: nSVM: Save/restore gPAT with KVM_{GET,SET}_NESTED_STATEJim Mattson
Add a 'gpat' field to kvm_svm_nested_state_hdr to carry L2's guest PAT value across save and restore. When KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT is disabled and the vCPU is in guest mode with nested NPT enabled, save vmcb02's g_pat into the header on KVM_GET_NESTED_STATE, and restore it on KVM_SET_NESTED_STATE. Host-initiated accesses to IA32_PAT (via KVM_GET/SET_MSRS) always target L1's hPAT, so they cannot be used to save or restore gPAT. The separate header field ensures that KVM_GET/SET_MSRS and KVM_GET/SET_NESTED_STATE are independent and can be ordered arbitrarily during save and restore. Note that struct kvm_svm_nested_state_hdr is included in a union padded to 120 bytes, so there is room to add the gpat field without changing any offsets. Fixes: cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE") Signed-off-by: Jim Mattson <jmattson@google.com> Link: https://patch.msgid.link/20260407190343.325299-9-jmattson@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-14KVM: Documentation: document KVM_{GET,SET}_NESTED_STATE for SVMJim Mattson
Document the nested state constants and structures for SVM that were added by commit cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE"). Fixes: cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE") Signed-off-by: Jim Mattson <jmattson@google.com> Link: https://patch.msgid.link/20260407190343.325299-8-jmattson@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-14KVM: x86: Define KVM_X86_QUIRK_NESTED_SVM_SHARED_PATJim Mattson
Define a quirk to control whether nested SVM shares L1's PAT with L2 (legacy behavior) or gives L2 its own independent gPAT (correct behavior per the APM). When the quirk is enabled (default), L2 shares L1's PAT, preserving the legacy KVM behavior. When userspace disables the quirk, KVM correctly virtualizes the PAT for nested SVM guests, giving L2 a separate gPAT as specified in the AMD architecture. Signed-off-by: Jim Mattson <jmattson@google.com> Link: https://patch.msgid.link/20260407190343.325299-2-jmattson@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-05-12Documentation: kvm: update links in the references section of AMD Memory ↵Ninad Naik
Encryption Replace non-working links in the reference section with the working ones. Signed-off-by: Ninad Naik <ninadnaik07@gmail.com> Link: https://patch.msgid.link/20260511174302.811918-1-ninadnaik07@gmail.com/ Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-10KVM: x86/mmu: move cr4_smep to base rolePaolo Bonzini
Guest page tables can be reused independent of the value of CR4.SMEP (at least if WP=1). However, this is not true of EPT MBEC pages, because presence of EPT entries is signaled by bits 0-2 when MBEC is off, and bits 0-2 + bit 10 when MBEC is on. In preparation for enabling MBEC, move cr4_smep to the base role. This makes the smep_andnot_wp bit redundant, so remove it. Tested-by: David Riley <d.riley@proxmox.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-04-13Merge tag 'kvm-s390-next-7.1-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - ESA nesting support - 4k memslots - LPSW/E fix
2026-04-08Merge branch kvm-arm64/pkvm-protected-guest into kvmarm-master/nextMarc Zyngier
* kvm-arm64/pkvm-protected-guest: (41 commits) : . : pKVM support for protected guests, implementing the very long : awaited support for anonymous memory, as the elusive guestmem : has failed to deliver on its promises despite a multi-year : effort. Patches courtesy of Will Deacon. From the initial cover : letter: : : "[...] this patch series implements support for protected guest : memory with pKVM, where pages are unmapped from the host as they are : faulted into the guest and can be shared back from the guest using pKVM : hypercalls. Protected guests are created using a new machine type : identifier and can be booted to a shell using the kvmtool patches : available at [2], which finally means that we are able to test the pVM : logic in pKVM. Since this is an incremental step towards full isolation : from the host (for example, the CPU register state and DMA accesses are : not yet isolated), creating a pVM requires a developer Kconfig option to : be enabled in addition to booting with 'kvm-arm.mode=protected' and : results in a kernel taint." : . KVM: arm64: Don't hold 'vm_table_lock' across guest page reclaim KVM: arm64: Allow get_pkvm_hyp_vm() to take a reference to a dying VM KVM: arm64: Prevent teardown finalisation of referenced 'hyp_vm' drivers/virt: pkvm: Add Kconfig dependency on DMA_RESTRICTED_POOL KVM: arm64: Rename PKVM_PAGE_STATE_MASK KVM: arm64: Extend pKVM page ownership selftests to cover guest hvcs KVM: arm64: Extend pKVM page ownership selftests to cover forced reclaim KVM: arm64: Register 'selftest_vm' in the VM table KVM: arm64: Extend pKVM page ownership selftests to cover guest donation KVM: arm64: Add some initial documentation for pKVM KVM: arm64: Allow userspace to create protected VMs when pKVM is enabled KVM: arm64: Implement the MEM_UNSHARE hypercall for protected VMs KVM: arm64: Implement the MEM_SHARE hypercall for protected VMs KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte KVM: arm64: Reclaim faulting page from pKVM in spurious fault handler KVM: arm64: Introduce hypercall to force reclaim of a protected page KVM: arm64: Annotate guest donations with handle and gfn in host stage-2 KVM: arm64: Change 'pkvm_handle_t' to u16 KVM: arm64: Introduce host_stage2_set_owner_metadata_locked() ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-04-02KVM: s390: Add KVM capability for ESA mode guestsHendrik Brueckner
Now that all the bits are properly addressed, provide a mechanism for testing ESA mode guests in nested configurations. Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> [farman@us.ibm.com: Updated commit message] Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2026-03-30KVM: arm64: Add some initial documentation for pKVMWill Deacon
Add some initial documentation for pKVM to help people understand what is supported, the limitations of protected VMs when compared to non-protected VMs and also what is left to do. Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Tested-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Will Deacon <will@kernel.org> Link: https://patch.msgid.link/20260330144841.26181-33-will@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-19KVM: arm64: gic-v5: Communicate userspace-driveable PPIs via a UAPISascha Bischoff
GICv5 systems will likely not support the full set of PPIs. The presence of any virtual PPI is tied to the presence of the physical PPI. Therefore, the available PPIs will be limited by the physical host. Userspace cannot drive any PPIs that are not implemented. Moreover, it is not desirable to expose all PPIs to the guest in the first place, even if they are supported in hardware. Some devices, such as the arch timer, are implemented in KVM, and hence those PPIs shouldn't be driven by userspace, either. Provided a new UAPI: KVM_DEV_ARM_VGIC_GRP_CTRL => KVM_DEV_ARM_VGIC_USERPSPACE_PPIs This allows userspace to query which PPIs it is able to drive via KVM_IRQ_LINE. Additionally, introduce a check in kvm_vm_ioctl_irq_line() to reject any PPIs not in the userspace mask. Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260319154937.3619520-40-sascha.bischoff@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-19Documentation: KVM: Introduce documentation for VGICv5Sascha Bischoff
Now that it is possible to create a VGICv5 device, provide initial documentation for it. At this stage, there is little to document. Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260319154937.3619520-39-sascha.bischoff@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-19KVM: arm64: gic-v5: Mandate architected PPI for PMU emulation on GICv5Sascha Bischoff
Make it mandatory to use the architected PPI when running a GICv5 guest. Attempts to set anything other than the architected PPI (23) are rejected. Additionally, KVM_ARM_VCPU_PMU_V3_INIT is relaxed to no longer require KVM_ARM_VCPU_PMU_V3_IRQ to be called for GICv5-based guests. In this case, the architectued PPI is automatically used. Documentation is bumped accordingly. Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Link: https://patch.msgid.link/20260319154937.3619520-33-sascha.bischoff@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-19KVM: arm64: gic-v5: Support GICv5 interrupts with KVM_IRQ_LINESascha Bischoff
Interrupts under GICv5 look quite different to those from older Arm GICs. Specifically, the type is encoded in the top bits of the interrupt ID. Extend KVM_IRQ_LINE to cope with GICv5 PPIs and SPIs. The requires subtly changing the KVM_IRQ_LINE API for GICv5 guests. For older Arm GICs, PPIs had to be in the range of 16-31, and SPIs had to be 32-1019, but this no longer holds true for GICv5. Instead, for a GICv5 guest support PPIs in the range of 0-127, and SPIs in the range 0-65535. The documentation is updated accordingly. The SPI range doesn't cover the full SPI range that a GICv5 system can potentially cope with (GICv5 provides up to 24-bits of SPI ID space, and we only have 16 bits to work with in KVM_IRQ_LINE). However, 65k SPIs is more than would be reasonably expected on systems for years to come. In order to use vgic_is_v5(), the kvm/arm_vgic.h header is added to kvm/arm.c. Note: As the GICv5 KVM implementation currently doesn't support injecting SPIs attempts to do so will fail. This restriction will by lifted as the GICv5 KVM support evolves. Co-authored-by: Timothy Hayes <timothy.hayes@arm.com> Signed-off-by: Timothy Hayes <timothy.hayes@arm.com> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Link: https://patch.msgid.link/20260319154937.3619520-28-sascha.bischoff@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-11Documentation: kvm: fix formatting of the quirks tablePaolo Bonzini
A recently added quirk does not fit in the left column of the table, so it all has to be reformatted and realigned. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-03-11KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMMJim Mattson
Add KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM to allow L1 to set FREEZE_IN_SMM in vmcs12's GUEST_IA32_DEBUGCTL field, as permitted prior to commit 6b1dd26544d0 ("KVM: VMX: Preserve host's DEBUGCTLMSR_FREEZE_IN_SMM while running the guest"). Enable the quirk by default for backwards compatibility (like all quirks); userspace can disable it via KVM_CAP_DISABLE_QUIRKS2 for consistency with the constraints on WRMSR(IA32_DEBUGCTL). Note that the quirk only bypasses the consistency check. The vmcs02 bit is still owned by the host, and PMCs are not frozen during virtualized SMM. In particular, if a host administrator decides that PMCs should not be frozen during physical SMM, then L1 has no say in the matter. Fixes: 095686e6fcb4 ("KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter") Cc: stable@vger.kernel.org Signed-off-by: Jim Mattson <jmattson@google.com> Link: https://patch.msgid.link/20260205231537.1278753-1-jmattson@google.com [sean: tag for stable@, clean-up and fix goofs in the comment and docs] Signed-off-by: Sean Christopherson <seanjc@google.com> [Rename quirk. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-03-11Merge tag 'kvm-x86-generic-7.0-rc3' of https://github.com/kvm-x86/linux into ↵Paolo Bonzini
HEAD KVM generic changes for 7.0 - Remove a subtle pseudo-overlay of kvm_stats_desc, which, aside from being unnecessary and confusing, triggered compiler warnings due to -Wflex-array-member-not-at-end. - Document that vcpu->mutex is take outside of kvm->slots_lock and kvm->slots_arch_lock, which is intentional and desirable despite being rather unintuitive.
2026-03-02Documentation: KVM: Formalizing taking vcpu->mutex *outside* of kvm->slots_lockSean Christopherson
Explicitly document the ordering of vcpu->mutex being taken *outside* of kvm->slots_lock. While somewhat unintuitive since vCPUs conceptually have narrower scope than VMs, the scope of the owning object (vCPU versus VM) doesn't automatically carry over to the lock. In this case, vcpu->mutex has far broader scope than kvm->slots_lock. As Paolo put it, it's a "don't worry about multiple ioctls at the same time" mutex that's intended to be taken at the outer edges of KVM. More importantly, arm64 and x86 have gained flows that take kvm->slots_lock inside of vcpu->mutex. x86's kvm_inhibit_apic_access_page() is particularly nasty, as slots_lock is taken quite deep within KVM_RUN, i.e. simply swapping the ordering isn't an option. Commit to the vcpu->mutex => kvm->slots_lock ordering, as vcpu->mutex really is intended to be a "top-level" lock, whereas kvm->slots_lock is "just" a helper lock. Opportunistically document that vcpu->mutex is also taken outside of slots_arch_lock, e.g. when allocating shadow roots on x86 (which is the entire reason slots_arch_lock exists, as shadow roots must be allocated while holding kvm->srcu) kvm_mmu_new_pgd() | -> kvm_mmu_reload() | -> kvm_mmu_load() | -> mmu_alloc_shadow_roots() | -> mmu_first_shadow_root_alloc() but also when manipulating memslots in vCPU context, e.g. when inhibiting the APIC-access page via the aforementioned kvm_inhibit_apic_access_page() kvm_inhibit_apic_access_page() | -> __x86_set_memory_region() | -> kvm_set_internal_memslot() | -> kvm_set_memory_region() | -> kvm_set_memslot() Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Marc Zyngier <maz@kernel.org> Link: https://patch.msgid.link/20260302170239.596810-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-02-28KVM: always define KVM_CAP_SYNC_MMUPaolo Bonzini
KVM_CAP_SYNC_MMU is provided by KVM's MMU notifiers, which are now always available. Move the definition from individual architectures to common code. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-02-11Merge tag 'kvm-s390-next-7.0-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - gmap rewrite: completely new memory management for kvm/s390 - vSIE improvement - maintainership change for s390 vfio-pci - small quality of life improvement for protected guests
2026-02-11Merge tag 'kvm-x86-gmem-6.20' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM guest_memfd changes for 6.20 - Remove kvm_gmem_populate()'s preparation tracking and half-baked hugepage handling, and instead rely on SNP (the only user of the tracking) to do its own tracking via the RMP. - Retroactively document and enforce (for SNP) that KVM_SEV_SNP_LAUNCH_UPDATE and KVM_TDX_INIT_MEM_REGION require the source page to be 4KiB aligned, to avoid non-trivial complexity for a non-existent usecase (and because in-place conversion simply can't support unaligned sources). - When populating guest_memfd memory, GUP the source page in common code and pass the refcounted page to the vendor callback, instead of letting vendor code do the heavy lifting. Doing so avoids a looming deadlock bug with in-place due an AB-BA conflict betwee mmap_lock and guest_memfd's filemap invalidate lock.
2026-02-09Merge tag 'kvm-x86-misc-6.20' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM x86 misc changes for 6.20 - Disallow changing the virtual CPU model if L2 is active, for all the same reasons KVM disallows change the model after the first KVM_RUN. - Fix a bug where KVM would incorrectly reject host accesses to PV MSRs that were advertised as supported to userspace when running with KVM_CAP_ENFORCE_PV_FEATURE_CPUID enabled. - Fix a bug where KVM would attempt to read protect guest state (CR3) when configuring an async #PF entry. - Fail the build if EXPORT_SYMBOL_GPL or EXPORT_SYMBOL is used in KVM (for x86 only) to enforce usage of EXPORT_SYMBOL_FOR_KVM_INTERNAL. Explicitly allow the few exports that are intended for external usage. - Ignore -EBUSY when checking nested events after a vCPU exits blocking as the WARN is user-triggerable, and because exiting to userspace on -EBUSY does more harm than good in pretty much every situation. - Throw in the towel and drop the WARN on INIT/SIPI being blocked when vCPU is in Wait-For-SIPI, as playing whack-a-mole with syzkaller turned out to be an unwinnable game. - Add support for new Intel instructions that don't require anything beyond enumerating feature flags to userspace. - Grab SRCU when reading PDPTRs in KVM_GET_SREGS2. - Add WARNs to guard against modifying KVM's CPU caps outside of the intended setup flow, as nested VMX in particular is sensitive to unexpected changes in KVM's golden configuration. - Add a quirk to allow userspace to opt-in to actually suppress EOI broadcasts when the suppression feature is enabled by the guest (currently limited to split IRQCHIP, i.e. userspace I/O APIC). Sadly, simply fixing KVM to honor Suppress EOI Broadcasts isn't an option as some userspaces have come to rely on KVM's buggy behavior (KVM advertises Supress EOI Broadcast irrespective of whether or not userspace I/O APIC supports Directed EOIs). - Minor cleanups.
2026-02-09Merge tag 'kvm-x86-svm-6.20' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
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.
2026-02-04KVM: s390: Storage key manipulation IOCTLClaudio Imbrenda
Add a new IOCTL to allow userspace to manipulate storage keys directly. This will make it easier to write selftests related to storage keys. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-01-30KVM: x86: Add x2APIC "features" to control EOI broadcast suppressionKhushit Shah
Add two flags for KVM_CAP_X2APIC_API to allow userspace to control support for Suppress EOI Broadcasts when using a split IRQCHIP (I/O APIC emulated by userspace), which KVM completely mishandles. When x2APIC support was first added, KVM incorrectly advertised and "enabled" Suppress EOI Broadcast, without fully supporting the I/O APIC side of the equation, i.e. without adding directed EOI to KVM's in-kernel I/O APIC. That flaw was carried over to split IRQCHIP support, i.e. KVM advertised support for Suppress EOI Broadcasts irrespective of whether or not the userspace I/O APIC implementation supported directed EOIs. Even worse, KVM didn't actually suppress EOI broadcasts, i.e. userspace VMMs without support for directed EOI came to rely on the "spurious" broadcasts. KVM "fixed" the in-kernel I/O APIC implementation by completely disabling support for Suppress EOI Broadcasts in commit 0bcc3fb95b97 ("KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use"), but didn't do anything to remedy userspace I/O APIC implementations. KVM's bogus handling of Suppress EOI Broadcast is problematic when the guest relies on interrupts being masked in the I/O APIC until well after the initial local APIC EOI. E.g. Windows with Credential Guard enabled handles interrupts in the following order: 1. Interrupt for L2 arrives. 2. L1 APIC EOIs the interrupt. 3. L1 resumes L2 and injects the interrupt. 4. L2 EOIs after servicing. 5. L1 performs the I/O APIC EOI. Because KVM EOIs the I/O APIC at step #2, the guest can get an interrupt storm, e.g. if the IRQ line is still asserted and userspace reacts to the EOI by re-injecting the IRQ, because the guest doesn't de-assert the line until step #4, and doesn't expect the interrupt to be re-enabled until step #5. Unfortunately, simply "fixing" the bug isn't an option, as KVM has no way of knowing if the userspace I/O APIC supports directed EOIs, i.e. suppressing EOI broadcasts would result in interrupts being stuck masked in the userspace I/O APIC due to step #5 being ignored by userspace. And fully disabling support for Suppress EOI Broadcast is also undesirable, as picking up the fix would require a guest reboot, *and* more importantly would change the virtual CPU model exposed to the guest without any buy-in from userspace. Add KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST and KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST flags to allow userspace to explicitly enable or disable support for Suppress EOI Broadcasts. This gives userspace control over the virtual CPU model exposed to the guest, as KVM should never have enabled support for Suppress EOI Broadcast without userspace opt-in. Not setting either flag will result in legacy quirky behavior for backward compatibility. Disallow fully enabling SUPPRESS_EOI_BROADCAST when using an in-kernel I/O APIC, as KVM's history/support is just as tragic. E.g. it's not clear that commit c806a6ad35bf ("KVM: x86: call irq notifiers with directed EOI") was entirely correct, i.e. it may have simply papered over the lack of Directed EOI emulation in the I/O APIC. Note, Suppress EOI Broadcasts is defined only in Intel's SDM, not in AMD's APM. But the bit is writable on some AMD CPUs, e.g. Turin, and KVM's ABI is to support Directed EOI (KVM's name) irrespective of guest CPU vendor. Fixes: 7543a635aa09 ("KVM: x86: Add KVM exit for IOAPIC EOIs") Closes: https://lore.kernel.org/kvm/7D497EF1-607D-4D37-98E7-DAF95F099342@nutanix.com Cc: stable@vger.kernel.org Suggested-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Khushit Shah <khushit.shah@nutanix.com> Link: https://patch.msgid.link/20260123125657.3384063-1-khushit.shah@nutanix.com [sean: clean up minor formatting goofs and fix a comment typo] Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-23KVM: SEV: Add KVM_SEV_SNP_ENABLE_REQ_CERTS commandMichael Roth
Introduce a new command for KVM_MEMORY_ENCRYPT_OP ioctl that can be used to enable fetching of endorsement key certificates from userspace via the new KVM_EXIT_SNP_REQ_CERTS exit type. Also introduce a new KVM_X86_SEV_SNP_REQ_CERTS KVM device attribute so that userspace can query whether the kernel supports the new command/exit. Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Tested-by: Liam Merwick <liam.merwick@oracle.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Link: https://patch.msgid.link/20260109231732.1160759-3-michael.roth@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-23KVM: Introduce KVM_EXIT_SNP_REQ_CERTS for SNP certificate-fetchingMichael Roth
For SEV-SNP, the host can optionally provide a certificate table to the guest when it issues an attestation request to firmware (see GHCB 2.0 specification regarding "SNP Extended Guest Requests"). This certificate table can then be used to verify the endorsement key used by firmware to sign the attestation report. While it is possible for guests to obtain the certificates through other means, handling it via the host provides more flexibility in being able to keep the certificate data in sync with the endorsement key throughout host-side operations that might resulting in the endorsement key changing. In the case of KVM, userspace will be responsible for fetching the certificate table and keeping it in sync with any modifications to the endorsement key by other userspace management tools. Define a new KVM_EXIT_SNP_REQ_CERTS event where userspace is provided with the GPA of the buffer the guest has provided as part of the attestation request so that userspace can write the certificate data into it while relying on filesystem-based locking to keep the certificates up-to-date relative to the endorsement keys installed/utilized by firmware at the time the certificates are fetched. [Melody: Update the documentation scheme about how file locking is expected to happen.] Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Tested-by: Liam Merwick <liam.merwick@oracle.com> Tested-by: Dionna Glaze <dionnaglaze@google.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Melody Wang <huibo.wang@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Link: https://patch.msgid.link/20260109231732.1160759-2-michael.roth@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-22KVM: arm64: Add documentation for KVM_EXIT_ARM_LDST64BMarc Zyngier
Add a bit of documentation for KVM_EXIT_ARM_LDST64B so that userspace knows what to expect. Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Oliver Upton <oupton@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Signed-off-by: Will Deacon <will@kernel.org>
2026-01-15KVM: TDX: Document alignment requirements for KVM_TDX_INIT_MEM_REGIONMichael Roth
Since it was never possible to use a non-PAGE_SIZE-aligned @source_addr, go ahead and document this as a requirement. This is in preparation for enforcing page-aligned @source_addr for all architectures in guest_memfd. Reviewed-by: Vishal Annapurve <vannapurve@google.com> Tested-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> Link: https://patch.msgid.link/20260108214622.1084057-6-michael.roth@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-15KVM: SEV: Document/enforce page-alignment for KVM_SEV_SNP_LAUNCH_UPDATEMichael Roth
In the past, KVM_SEV_SNP_LAUNCH_UPDATE accepted a non-page-aligned 'uaddr' parameter to copy data from, but continuing to support this with new functionality like in-place conversion and hugepages in the pipeline has proven to be more trouble than it is worth, since there are no known users that have been identified who use a non-page-aligned 'uaddr' parameter. Rather than locking guest_memfd into continuing to support this, go ahead and document page-alignment as a requirement and begin enforcing this in the handling function. Reviewed-by: Vishal Annapurve <vannapurve@google.com> Tested-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Link: https://patch.msgid.link/20260108214622.1084057-5-michael.roth@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-12-02Merge tag 'kvm-s390-next-6.19-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - SCA rework - VIRT_XFER_TO_GUEST_WORK support - Operation exception forwarding support - Cleanups
2025-12-02Merge tag 'kvmarm-6.19' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.19 - Support for userspace handling of synchronous external aborts (SEAs), allowing the VMM to potentially handle the abort in a non-fatal manner. - Large rework of the VGIC's list register handling with the goal of supporting more active/pending IRQs than available list registers in hardware. In addition, the VGIC now supports EOImode==1 style deactivations for IRQs which may occur on a separate vCPU than the one that acked the IRQ. - Support for FEAT_XNX (user / privileged execute permissions) and FEAT_HAF (hardware update to the Access Flag) in the software page table walkers and shadow MMU. - Allow page table destruction to reschedule, fixing long need_resched latencies observed when destroying a large VM. - Minor fixes to KVM and selftests
2025-12-02Merge tag 'kvm-riscv-6.19-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.19 - SBI MPXY support for KVM guest - New KVM_EXIT_FAIL_ENTRY_NO_VSFILE for the case when in-kernel AIA virtualization fails to allocate IMSIC VS-file - Support enabling dirty log gradually in small chunks - Fix guest page fault within HLV* instructions - Flush VS-stage TLB after VCPU migration for Andes cores
2025-11-26Merge tag 'kvm-x86-svm-6.19' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM SVM changes for 6.19: - Fix a few missing "VMCB dirty" bugs. - Fix the worst of KVM's lack of EFER.LMSLE emulation. - Add AVIC support for addressing 4k vCPUs in x2AVIC mode. - Fix incorrect handling of selective CR0 writes when checking intercepts during emulation of L2 instructions. - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32] on VMRUN and #VMEXIT. - Fix a bug where KVM corrupt the guest code stream when re-injecting a soft interrupt if the guest patched the underlying code after the VM-Exit, e.g. when Linux patches code with a temporary INT3. - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits to userspace, and extend KVM "support" to all policy bits that don't require any actual support from KVM.
2025-11-26Merge tag 'kvm-x86-generic-6.19' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM generic changes for 6.19: - Use the recently-added WQ_PERCPU when creating the per-CPU workqueue for irqfd cleanup. - Fix a goof in the dirty ring documentation.
2025-11-24KVM: riscv: Support enabling dirty log gradually in small chunksDong Yang
There is already support of enabling dirty log gradually in small chunks for x86 in commit 3c9bd4006bfc ("KVM: x86: enable dirty log gradually in small chunks") and c862626 ("KVM: arm64: Support enabling dirty log gradually in small chunks"). This adds support for riscv. x86 and arm64 writes protect both huge pages and normal pages now, so riscv protect also protects both huge pages and normal pages. On a nested virtualization setup (RISC-V KVM running inside a QEMU VM on an [Intel® Core™ i5-12500H] host), I did some tests with a 2G Linux VM using different backing page sizes. The time taken for memory_global_dirty_log_start in the L2 QEMU is listed below: Page Size Before After Optimization 4K 4490.23ms 31.94ms 2M 48.97ms 45.46ms 1G 28.40ms 30.93ms Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn> Signed-off-by: Dong Yang <dayss1224@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20251103062825.9084-1-dayss1224@gmail.com Signed-off-by: Anup Patel <anup@brainfault.org>
2025-11-21KVM: s390: Add capability that forwards operation exceptionsJanosch Frank
Setting KVM_CAP_S390_USER_OPEREXEC will forward all operation exceptions to user space. This also includes the 0x0000 instructions managed by KVM_CAP_S390_USER_INSTR0. It's helpful if user space wants to emulate instructions which do not (yet) have an opcode. While we're at it refine the documentation for KVM_CAP_S390_USER_INSTR0. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>