linux/Documentation/virt, branch v6.17

Documentation: KVM: Use unordered list for pre-init VGIC registers

2025-07-29T17:43:50Z

The intent was to create a single column table, however the markup used was actually for a header which led to docs build failures: Sphinx parallel build error: docutils.utils.SystemMessage: Documentation/virt/kvm/devices/arm-vgic-v3.rst:128: (SEVERE/4) Unexpected section title or transition. Fix the issue by converting the attempted table to an unordered list. Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/linux-next/20250729142217.0d4e64cd@canb.auug.org.au/ Signed-off-by: Oliver Upton Message-ID: <20250729152242.3232229-1-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini

Merge tag 'kvmarm-6.17' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2025-07-29T16:27:40Z

KVM/arm64 changes for 6.17, round #1 - Host driver for GICv5, the next generation interrupt controller for arm64, including support for interrupt routing, MSIs, interrupt translation and wired interrupts. - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on GICv5 hardware, leveraging the legacy VGIC interface. - Userspace control of the 'nASSGIcap' GICv3 feature, allowing userspace to disable support for SGIs w/o an active state on hardware that previously advertised it unconditionally. - Map supporting endpoints with cacheable memory attributes on systems with FEAT_S2FWB and DIC where KVM no longer needs to perform cache maintenance on the address range. - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest hypervisor to inject external aborts into an L2 VM and take traps of masked external aborts to the hypervisor. - Convert more system register sanitization to the config-driven implementation. - Fixes to the visibility of EL2 registers, namely making VGICv3 system registers accessible through the VGIC device instead of the ONE_REG vCPU ioctls. - Various cleanups and minor fixes.

Merge tag 'kvm-x86-misc-6.17' of https://github.com/kvm-x86/linux into HEAD

2025-07-29T12:36:43Z

KVM x86 misc changes for 6.17 - Prevert the host's DEBUGCTL.FREEZE_IN_SMM (Intel only) when running the guest. Failure to honor FREEZE_IN_SMM can bleed host state into the guest. - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter (Intel only) to prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF. - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the vCPU's CPUID model. - Rework the MSR interception code so that the SVM and VMX APIs are more or less identical. - Recalculate all MSR intercepts from the "source" on MSR filter changes, and drop the dedicated "shadow" bitmaps (and their awful "max" size defines). - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the nested SVM MSRPM offsets tracker can't handle an MSR. - Advertise support for LKGS (Load Kernel GS base), a new instruction that's loosely related to FRED, but is supported and enumerated independently. - Fix a user-triggerable WARN that syzkaller found by stuffing INIT_RECEIVED, a.k.a. WFS, and then putting the vCPU into VMX Root Mode (post-VMXON). Use the same approach KVM uses for dealing with "impossible" emulation when running a !URG guest, and simply wait until KVM_RUN to detect that the vCPU has architecturally impossible state. - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of APERF/MPERF reads, so that a "properly" configured VM can "virtualize" APERF/MPERF (with many caveats). - Reject KVM_SET_TSC_KHZ if vCPUs have been created, as changing the "default" frequency is unsupported for VMs with a "secure" TSC, and there's no known use case for changing the default frequency for other VM types.

Merge tag 'kvm-riscv-6.17-2' of https://github.com/kvm-riscv/linux into HEAD

2025-07-29T12:33:04Z

KVM/riscv changes for 6.17 - Enabled ring-based dirty memory tracking - Improved perf kvm stat to report interrupt events - Delegate illegal instruction trap to VS-mode - MMU related improvements for KVM RISC-V for upcoming nested virtualization

RISC-V: KVM: Enable ring-based dirty memory tracking

2025-07-28T16:58:22Z

Enable ring-based dirty memory tracking on riscv: - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as riscv is weakly ordered. - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page offset. - Add a check to kvm_vcpu_kvm_riscv_check_vcpu_requests for checking whether the dirty ring is soft full. To handle vCPU requests that cause exits to userspace, modified the `kvm_riscv_check_vcpu_requests` to return a value (currently only returns 0 or 1). Signed-off-by: Quan Zhou Reviewed-by: Anup Patel Link: https://lore.kernel.org/r/20e116efb1f7aff211dd8e3cf8990c5521ed5f34.1749810735.git.zhouquan@iscas.ac.cn Signed-off-by: Anup Patel

Merge branch 'kvm-arm64/vgic-v4-ctl' into kvmarm/next

2025-07-28T15:11:38Z

* kvm-arm64/vgic-v4-ctl: : Userspace control of nASSGIcap, courtesy of Raghavendra Rao Ananta : : Allow userspace to decide if support for SGIs without an active state is : advertised to the guest, allowing VMs from GICv3-only hardware to be : migrated to to GICv4.1 capable machines. Documentation: KVM: arm64: Describe VGICv3 registers writable pre-init KVM: arm64: selftests: Add test for nASSGIcap attribute KVM: arm64: vgic-v3: Allow userspace to write GICD_TYPER2.nASSGIcap KVM: arm64: vgic-v3: Allow access to GICD_IIDR prior to initialization KVM: arm64: vgic-v3: Consolidate MAINT_IRQ handling KVM: arm64: Disambiguate support for vSGIs v. vLPIs Signed-off-by: Oliver Upton

Merge branch 'kvm-arm64/el2-reg-visibility' into kvmarm/next

2025-07-28T15:06:38Z

* kvm-arm64/el2-reg-visibility: : Fixes to EL2 register visibility, courtesy of Marc Zyngier : : - Expose EL2 VGICv3 registers via the VGIC attributes accessor, not the : KVM_{GET,SET}_ONE_REG ioctls : : - Condition visibility of FGT registers on the presence of FEAT_FGT in : the VM KVM: arm64: selftest: vgic-v3: Add basic GICv3 sysreg userspace access test KVM: arm64: Enforce the sorting of the GICv3 system register table KVM: arm64: Clarify the check for reset callback in check_sysreg_table() KVM: arm64: vgic-v3: Fix ordering of ICH_HCR_EL2 KVM: arm64: Document registers exposed via KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS KVM: arm64: selftests: get-reg-list: Add base EL2 registers KVM: arm64: selftests: get-reg-list: Simplify feature dependency KVM: arm64: Advertise FGT2 registers to userspace KVM: arm64: Condition FGT registers on feature availability KVM: arm64: Expose GICv3 EL2 registers via KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS KVM: arm64: Let GICv3 save/restore honor visibility attribute KVM: arm64: Define helper for ICH_VTR_EL2 KVM: arm64: Define constant value for ICC_SRE_EL2 KVM: arm64: Don't advertise ICH_*_EL2 registers through GET_ONE_REG KVM: arm64: Make RVBAR_EL2 accesses UNDEF Signed-off-by: Oliver Upton

Documentation: KVM: arm64: Describe VGICv3 registers writable pre-init

2025-07-26T15:45:52Z

KVM allows userspace to control GICD_IIDR.Revision and GICD_TYPER2.nASSGIcap prior to initialization for the sake of provisioning the guest-visible feature set. Document the userspace expectations surrounding accesses to these registers. Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20250724062805.2658919-7-oliver.upton@linux.dev Signed-off-by: Oliver Upton

Merge tag 'kvm-x86-fixes-6.16-rc7' of https://github.com/kvm-x86/linux into HEAD

2025-07-17T15:06:13Z

KVM TDX fixes for 6.16 - Fix a formatting goof in the TDX documentation. - Reject KVM_SET_TSC_KHZ for guests with a protected TSC (currently only TDX). - Ensure struct kvm_tdx_capabilities fields that are not explicitly set by KVM are zeroed.

KVM: arm64: Document registers exposed via KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS

2025-07-16T03:25:40Z

We never documented which GICv3 registers are available for save/restore via the KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS interface. Let's take the opportunity of adding the EL2 registers to document the whole thing in one go. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20250714122634.3334816-12-maz@kernel.org [ oliver: fix trailing whitespace ] Signed-off-by: Oliver Upton