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3 daysMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - 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 LoongArch: - Add stat information for in-kernel irqchip - Add tracepoints for CPUCFG and CSR emulation exits - Enhance in-kernel irqchip emulation - Various cleanups RISC-V: - Enable ring-based dirty memory tracking - Improve perf kvm stat to report interrupt events - Delegate illegal instruction trap to VS-mode - MMU improvements related to upcoming nested virtualization s390x - Fixes x86: - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC, and PIT emulation at compile time - Share device posted IRQ code between SVM and VMX and harden it against bugs and runtime errors - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1) instead of O(n) - For MMIO stale data mitigation, track whether or not a vCPU has access to (host) MMIO based on whether the page tables have MMIO pfns mapped; using VFIO is prone to false negatives - Rework the MSR interception code so that the SVM and VMX APIs are more or less identical - Recalculate all MSR intercepts from scratch on MSR filter changes, instead of maintaining shadow bitmaps - 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 setting the vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting the vCPU into VMX Root Mode (post-VMXON). Trying to detect every possible path leading to architecturally forbidden states is hard and even risks breaking userspace (if it goes from valid to valid state but passes through invalid states), so just wait until KVM_RUN to detect that the vCPU state isn't allowed - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of APERF/MPERF reads, so that a "properly" configured VM can access APERF/MPERF. This has many caveats (APERF/MPERF cannot be zeroed on vCPU creation or saved/restored on suspend and resume, or preserved over thread migration let alone VM migration) but can be useful whenever you're interested in letting Linux guests see the effective physical CPU frequency in /proc/cpuinfo - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been created, as there's no known use case for changing the default frequency for other VM types and it goes counter to the very reason why the ioctl was added to the vm file descriptor. And also, there would be no way to make it work for confidential VMs with a "secure" TSC, so kill two birds with one stone - Dynamically allocation the shadow MMU's hashed page list, and defer allocating the hashed list until it's actually needed (the TDP MMU doesn't use the list) - Extract many of KVM's helpers for accessing architectural local APIC state to common x86 so that they can be shared by guest-side code for Secure AVIC - Various cleanups and fixes x86 (Intel): - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest. Failure to honor FREEZE_IN_SMM can leak host state into guests - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF x86 (AMD): - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the nested SVM MSRPM offsets tracker can't handle an MSR (which is pretty much a static condition and therefore should never happen, but still) - Fix a variety of flaws and bugs in the AVIC device posted IRQ code - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware supports) instead of rejecting vCPU creation - Extend enable_ipiv module param support to SVM, by simply leaving IsRunning clear in the vCPU's physical ID table entry - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by erratum #1235, to allow (safely) enabling AVIC on such CPUs - Request GA Log interrupts if and only if the target vCPU is blocking, i.e. only if KVM needs a notification in order to wake the vCPU - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the vCPU's CPUID model - Accept any SNP policy that is accepted by the firmware with respect to SMT and single-socket restrictions. An incompatible policy doesn't put the kernel at risk in any way, so there's no reason for KVM to care - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and use WBNOINVD instead of WBINVD when possible for SEV cache maintenance - When reclaiming memory from an SEV guest, only do cache flushes on CPUs that have ever run a vCPU for the guest, i.e. don't flush the caches for CPUs that can't possibly have cache lines with dirty, encrypted data Generic: - Rework irqbypass to track/match producers and consumers via an xarray instead of a linked list. Using a linked list leads to O(n^2) insertion times, which is hugely problematic for use cases that create large numbers of VMs. Such use cases typically don't actually use irqbypass, but eliminating the pointless registration is a future problem to solve as it likely requires new uAPI - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *", to avoid making a simple concept unnecessarily difficult to understand - Decouple device posted IRQs from VFIO device assignment, as binding a VM to a VFIO group is not a requirement for enabling device posted IRQs - Clean up and document/comment the irqfd assignment code - Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e. ensure an eventfd is bound to at most one irqfd through the entire host, and add a selftest to verify eventfd:irqfd bindings are globally unique - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues related to private <=> shared memory conversions - Drop guest_memfd's .getattr() implementation as the VFS layer will call generic_fillattr() if inode_operations.getattr is NULL - Fix issues with dirty ring harvesting where KVM doesn't bound the processing of entries in any way, which allows userspace to keep KVM in a tight loop indefinitely - Kill off kvm_arch_{start,end}_assignment() and x86's associated tracking, now that KVM no longer uses assigned_device_count as a heuristic for either irqbypass usage or MDS mitigation Selftests: - Fix a comment typo - Verify KVM is loaded when getting any KVM module param so that attempting to run a selftest without kvm.ko loaded results in a SKIP message about KVM not being loaded/enabled (versus some random parameter not existing) - Skip tests that hit EACCES when attempting to access a file, and print a "Root required?" help message. In most cases, the test just needs to be run with elevated permissions" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits) Documentation: KVM: Use unordered list for pre-init VGIC registers RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map() RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs RISC-V: perf/kvm: Add reporting of interrupt events RISC-V: KVM: Enable ring-based dirty memory tracking RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap RISC-V: KVM: Delegate illegal instruction fault to VS mode RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs RISC-V: KVM: Factor-out g-stage page table management RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence RISC-V: KVM: Introduce struct kvm_gstage_mapping RISC-V: KVM: Factor-out MMU related declarations into separate headers RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect() RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range() RISC-V: KVM: Don't flush TLB when PTE is unchanged RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize() RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init() RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list ...
4 daysMerge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "A quick summary: perf support for Branch Record Buffer Extensions (BRBE), typical PMU hardware updates, small additions to MTE for store-only tag checking and exposing non-address bits to signal handlers, HAVE_LIVEPATCH enabled on arm64, VMAP_STACK forced on. There is also a TLBI optimisation on hardware that does not require break-before-make when changing the user PTEs between contiguous and non-contiguous. More details: Perf and PMU updates: - Add support for new (v3) Hisilicon SLLC and DDRC PMUs - Add support for Arm-NI PMU integrations that share interrupts between clock domains within a given instance - Allow SPE to be configured with a lower sample period than the minimum recommendation advertised by PMSIDR_EL1.Interval - Add suppport for Arm's "Branch Record Buffer Extension" (BRBE) - Adjust the perf watchdog period according to cpu frequency changes - Minor driver fixes and cleanups Hardware features: - Support for MTE store-only checking (FEAT_MTE_STORE_ONLY) - Support for reporting the non-address bits during a synchronous MTE tag check fault (FEAT_MTE_TAGGED_FAR) - Optimise the TLBI when folding/unfolding contiguous PTEs on hardware with FEAT_BBM (break-before-make) level 2 and no TLB conflict aborts Software features: - Enable HAVE_LIVEPATCH after implementing arch_stack_walk_reliable() and using the text-poke API for late module relocations - Force VMAP_STACK always on and change arm64_efi_rt_init() to use arch_alloc_vmap_stack() in order to avoid KASAN false positives ACPI: - Improve SPCR handling and messaging on systems lacking an SPCR table Debug: - Simplify the debug exception entry path - Drop redundant DBG_MDSCR_* macros Kselftests: - Cleanups and improvements for SME, SVE and FPSIMD tests Miscellaneous: - Optimise loop to reduce redundant operations in contpte_ptep_get() - Remove ISB when resetting POR_EL0 during signal handling - Mark the kernel as tainted on SEA and SError panic - Remove redundant gcs_free() call" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits) arm64/gcs: task_gcs_el0_enable() should use passed task arm64: Kconfig: Keep selects somewhat alphabetically ordered arm64: signal: Remove ISB when resetting POR_EL0 kselftest/arm64: Handle attempts to disable SM on SME only systems kselftest/arm64: Fix SVE write data generation for SME only systems kselftest/arm64: Test SME on SME only systems in fp-ptrace kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace kselftest/arm64: Allow sve-ptrace to run on SME only systems arm64/mm: Drop redundant addr increment in set_huge_pte_at() kselftest/arm4: Provide local defines for AT_HWCAP3 arm64: Mark kernel as tainted on SAE and SError panic arm64/gcs: Don't call gcs_free() when releasing task_struct drivers/perf: hisi: Support PMUs with no interrupt drivers/perf: hisi: Relax the event number check of v2 PMUs drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver drivers/perf: hisi: Simplify the probe process for each DDRC version perf/arm-ni: Support sharing IRQs within an NI instance perf/arm-ni: Consolidate CPU affinity handling ...
4 daysMerge tag 'kvmarm-6.17' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD 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.
5 daysMerge branch 'kvm-arm64/el2-reg-visibility' into kvmarm/nextOliver Upton
* 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 <oliver.upton@linux.dev>
7 daysMerge branch 'kvm-arm64/misc' into kvmarm/nextOliver Upton
* kvm-arm64/misc: : Miscellaneous fixes/cleanups for KVM/arm64 : : - Fixes for computing POE output permissions : : - Return ENXIO for invalid VGIC device attribute : : - String helper conversions arm64: kvm: trace_handle_exit: use string choices helper arm64: kvm: sys_regs: use string choices helper KVM: arm64: Follow specification when implementing WXN KVM: arm64: Remove the wi->{e0,}poe vs wr->{p,u}ov confusion KVM: arm64: vgic-its: Return -ENXIO to invalid KVM_DEV_ARM_VGIC_GRP_CTRL attrs Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
7 daysMerge branch 'kvm-arm64/gcie-legacy' into kvmarm/nextOliver Upton
* kvm-arm64/gcie-legacy: : Support for GICv3 emulation on GICv5, courtesy of Sascha Bischoff : : FEAT_GCIE_LEGACY adds the necessary hardware for GICv5 systems to : support the legacy GICv3 for VMs, including a backwards-compatible VGIC : implementation that we all know and love. : : As a starting point for GICv5 enablement in KVM, enable + use the : GICv3-compatible feature when running VMs on GICv5 hardware. KVM: arm64: gic-v5: Probe for GICv5 KVM: arm64: gic-v5: Support GICv3 compat arm64/sysreg: Add ICH_VCTLR_EL2 irqchip/gic-v5: Populate struct gic_kvm_info irqchip/gic-v5: Skip deactivate for forwarded PPI interrupts Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
7 daysKVM: arm64: Enforce the sorting of the GICv3 system register tableMarc Zyngier
In order to avoid further embarassing bugs, enforce that the GICv3 sysreg table is actually sorted, just like all the other tables. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Sebastian Ott <sebott@redhat.com> Link: https://lore.kernel.org/r/20250718111154.104029-4-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
7 daysKVM: arm64: Clarify the check for reset callback in check_sysreg_table()Marc Zyngier
check_sysreg_table() has a wonky 'is_32" parameter, which is really an indication that we should enforce the presence of a reset helper. Clean this up by naming the variable accordingly and inverting the condition. Contrary to popular belief, system instructions don't have a reset value (duh!), and therefore do not need to be checked for reset (they escaped the check through luck...). Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Sebastian Ott <sebott@redhat.com> Link: https://lore.kernel.org/r/20250718111154.104029-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
9 daysarm64: kvm: sys_regs: use string choices helperKuninori Morimoto
We can use string choices helper, let's use it. Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Link: https://lore.kernel.org/r/87pldy5ktb.wl-kuninori.morimoto.gx@renesas.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
12 daysKVM: arm64: Make RAS registers UNDEF when RAS isn't advertisedMarc Zyngier
We currently always expose FEAT_RAS when available on the host. As we are about to make this feature selectable from userspace, check for it being present before emulating register accesses as RAZ/WI, and inject an UNDEF otherwise. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250721101955.535159-4-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15KVM: arm64: Advertise FGT2 registers to userspaceMarc Zyngier
While a guest is able to use the FEAT_FGT2 registers, we're missing them being exposed to userspace. Add them to the (very long) list. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250714122634.3334816-9-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15KVM: arm64: Condition FGT registers on feature availabilityMarc Zyngier
We shouldn't expose the FEAT_FGT registers unconditionally. Make them dependent on FEAT_FGT being actually advertised to the guest. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250714122634.3334816-8-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15KVM: arm64: Define helper for ICH_VTR_EL2Marc Zyngier
Move the computation of the ICH_VTR_EL2 value to a common location, so that it can be reused by the save/restore code. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250714122634.3334816-5-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15KVM: arm64: Define constant value for ICC_SRE_EL2Marc Zyngier
Move the bag of bits defining the value of ICC_SRE_EL2 to a common spot so that it can be reused by the save/restore code. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250714122634.3334816-4-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15KVM: arm64: Don't advertise ICH_*_EL2 registers through GET_ONE_REGMarc Zyngier
It appears that exposing the GICv3 EL2 registers through the usual sysreg interface is not consistent with the way we expose the EL1 registers. The latter are exposed via the GICv3 device interface instead, and there is no reason why the EL2 registers should get a different treatement. Hide the registers from userspace until the GICv3 code grows the required infrastructure. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250714122634.3334816-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-15KVM: arm64: Make RVBAR_EL2 accesses UNDEFMarc Zyngier
We always expose a virtual CPU that has EL3 when NV is enabled, irrespective of EL3 being actually implemented in HW. Therefore, as per the architecture, RVBAR_EL2 must UNDEF, since EL2 is not the highest implemented exception level. This is consistent with RMR_EL2 also triggering an UNDEF. Adjust the handling of RVBAR_EL2 accordingly. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250714122634.3334816-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-09KVM: arm64: Fix enforcement of upper bound on MDCR_EL2.HPMNBen Horgan
Previously, u64_replace_bits() was used to no effect as the return value was ignored. Convert to u64p_replace_bits() so the value is updated in place. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Fixes: efff9dd2fee7 ("KVM: arm64: Handle out-of-bound write to MDCR_EL2.HPMN") Link: https://lore.kernel.org/r/20250709093808.920284-2-ben.horgan@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-08KVM: arm64: gic-v5: Support GICv3 compatSascha Bischoff
Add support for GICv3 compat mode (FEAT_GCIE_LEGACY) which allows a GICv5 host to run GICv3-based VMs. This change enables the VHE/nVHE/hVHE/protected modes, but does not support nested virtualization. A lazy-disable approach is taken for compat mode; it is enabled on the vgic_v3_load path but not disabled on the vgic_v3_put path. A non-GICv3 VM, i.e., one based on GICv5, is responsible for disabling compat mode on the corresponding vgic_v5_load path. Currently, GICv5 is not supported, and hence compat mode is not disabled again once it is enabled, and this function is intentionally omitted from the code. 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> Link: https://lore.kernel.org/r/20250627100847.1022515-5-sascha.bischoff@arm.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08KVM: arm64: Advertise support for FEAT_DoubleFault2Oliver Upton
KVM's external abort injection now respects the exception routing wreckage due to FEAT_DoubleFault2. Advertise the feature. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250708172532.1699409-23-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08KVM: arm64: Advertise support for FEAT_SCTLR2Oliver Upton
Everything is in place to handle the additional state for SCTLR2_ELx, which is all that FEAT_SCTLR2 implies. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250708172532.1699409-22-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08KVM: arm64: Wire up SCTLR2_ELx sysreg descriptorsOliver Upton
Set up the sysreg descriptors for SCTLR2_ELx, along with the associated storage and VNCR mapping. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250708172532.1699409-12-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-08KVM: arm64: nv: Add FEAT_RAS vSError sys regs to tableOliver Upton
Prepare to implement RAS for NV by adding the missing EL2 sysregs for the vSError context. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250708172532.1699409-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-02KVM: arm64: Expose MTE_STORE_ONLY feature to guestYeoreum Yun
expose MTE_STORE_ONLY feature to guest. Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250618092957.2069907-6-yeoreum.yun@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-07-02KVM: arm64: Expose FEAT_MTE_TAGGED_FAR feature to guestYeoreum Yun
expose FEAT_MTE_TAGGED_FAR feature to guest. Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250618084513.1761345-4-yeoreum.yun@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-06-11Merge tag 'kvmarm-fixes-6.16-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.16, take #2 - Rework of system register accessors for system registers that are directly writen to memory, so that sanitisation of the in-memory value happens at the correct time (after the read, or before the write). For convenience, RMW-style accessors are also provided. - Multiple fixes for the so-called "arch-timer-edge-cases' selftest, which was always broken.
2025-06-05KVM: arm64: Add RMW specific sysreg accessorMarc Zyngier
In a number of cases, we perform a Read-Modify-Write operation on a system register, meaning that we would apply the RESx masks twice. Instead, provide a new accessor that performs this RMW operation, allowing the masks to be applied exactly once per operation. Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250603070824.1192795-3-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-06-05KVM: arm64: Add assignment-specific sysreg accessorMarc Zyngier
Assigning a value to a system register doesn't do what it is supposed to be doing if that register is one that has RESx bits. The main problem is that we use __vcpu_sys_reg(), which can be used both as a lvalue and rvalue. When used as a lvalue, the bit masking occurs *before* the new value is assigned, meaning that we (1) do pointless work on the old cvalue, and (2) potentially assign an invalid value as we fail to apply the masks to it. Fix this by providing a new __vcpu_assign_sys_reg() that does what it says on the tin, and sanitises the *new* value instead of the old one. This comes with a significant amount of churn. Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250603070824.1192795-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-26Merge tag 'kvmarm-6.16' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.16 * New features: - Add large stage-2 mapping support for non-protected pKVM guests, clawing back some performance. - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and protected modes. - Enable nested virtualisation support on systems that support it (yes, it has been a long time coming), though it is disabled by default. * Improvements, fixes and cleanups: - Large rework of the way KVM tracks architecture features and links them with the effects of control bits. This ensures correctness of emulation (the data is automatically extracted from the published JSON files), and helps dealing with the evolution of the architecture. - Significant changes to the way pKVM tracks ownership of pages, avoiding page table walks by storing the state in the hypervisor's vmemmap. This in turn enables the THP support described above. - New selftest checking the pKVM ownership transition rules - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests even if the host didn't have it. - Fixes for the address translation emulation, which happened to be rather buggy in some specific contexts. - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N from the number of counters exposed to a guest and addressing a number of issues in the process. - Add a new selftest for the SVE host state being corrupted by a guest. - Keep HCR_EL2.xMO set at all times for systems running with the kernel at EL2, ensuring that the window for interrupts is slightly bigger, and avoiding a pretty bad erratum on the AmpereOne HW. - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers from a pretty bad case of TLB corruption unless accesses to HCR_EL2 are heavily synchronised. - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS tables in a human-friendly fashion. - and the usual random cleanups.
2025-05-23Merge branch kvm-arm64/nv-nv into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-nv: : . : Flick the switch on the NV support by adding the missing piece : in the form of the VNCR page management. From the cover letter: : : "This is probably the most interesting bit of the whole NV adventure. : So far, everything else has been a walk in the park, but this one is : where the real fun takes place. : : With FEAT_NV2, most of the NV support revolves around tricking a guest : into accessing memory while it tries to access system registers. The : hypervisor's job is to handle the context switch of the actual : registers with the state in memory as needed." : . KVM: arm64: nv: Release faulted-in VNCR page from mmu_lock critical section KVM: arm64: nv: Handle TLBI S1E2 for VNCR invalidation with mmu_lock held KVM: arm64: nv: Hold mmu_lock when invalidating VNCR SW-TLB before translating KVM: arm64: Document NV caps and vcpu flags KVM: arm64: Allow userspace to request KVM_ARM_VCPU_EL2* KVM: arm64: nv: Remove dead code from ERET handling KVM: arm64: nv: Plumb TLBI S1E2 into system instruction dispatch KVM: arm64: nv: Add S1 TLB invalidation primitive for VNCR_EL2 KVM: arm64: nv: Program host's VNCR_EL2 to the fixmap address KVM: arm64: nv: Handle VNCR_EL2 invalidation from MMU notifiers KVM: arm64: nv: Handle mapping of VNCR_EL2 at EL2 KVM: arm64: nv: Handle VNCR_EL2-triggered faults KVM: arm64: nv: Add userspace and guest handling of VNCR_EL2 KVM: arm64: nv: Add pseudo-TLB backing VNCR_EL2 KVM: arm64: nv: Don't adjust PSTATE.M when L2 is nesting KVM: arm64: nv: Move TLBI range decoding to a helper KVM: arm64: nv: Snapshot S1 ASID tagging information during walk KVM: arm64: nv: Extract translation helper from the AT code KVM: arm64: nv: Allocate VNCR page when required arm64: sysreg: Add layout for VNCR_EL2 Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23Merge branch kvm-arm64/fgt-masks into kvmarm-master/nextMarc Zyngier
* kvm-arm64/fgt-masks: (43 commits) : . : Large rework of the way KVM deals with trap bits in conjunction with : the CPU feature registers. It now draws a direct link between which : the feature set, the system registers that need to UNDEF to match : the configuration and bits that need to behave as RES0 or RES1 in : the trap registers that are visible to the guest. : : Best of all, these definitions are mostly automatically generated : from the JSON description published by ARM under a permissive : license. : . KVM: arm64: Handle TSB CSYNC traps KVM: arm64: Add FGT descriptors for FEAT_FGT2 KVM: arm64: Allow sysreg ranges for FGT descriptors KVM: arm64: Add context-switch for FEAT_FGT2 registers KVM: arm64: Add trap routing for FEAT_FGT2 registers KVM: arm64: Add sanitisation for FEAT_FGT2 registers KVM: arm64: Add FEAT_FGT2 registers to the VNCR page KVM: arm64: Use HCR_EL2 feature map to drive fixed-value bits KVM: arm64: Use HCRX_EL2 feature map to drive fixed-value bits KVM: arm64: Allow kvm_has_feat() to take variable arguments KVM: arm64: Use FGT feature maps to drive RES0 bits KVM: arm64: Validate FGT register descriptions against RES0 masks KVM: arm64: Switch to table-driven FGU configuration KVM: arm64: Handle PSB CSYNC traps KVM: arm64: Use KVM-specific HCRX_EL2 RES0 mask KVM: arm64: Remove hand-crafted masks for FGT registers KVM: arm64: Use computed FGT masks to setup FGT registers KVM: arm64: Propagate FGT masks to the nVHE hypervisor KVM: arm64: Unconditionally configure fine-grain traps KVM: arm64: Use computed masks as sanitisers for FGT registers ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23Merge branch kvm-arm64/mte-frac into kvmarm-master/nextMarc Zyngier
* kvm-arm64/mte-frac: : . : Prevent FEAT_MTE_ASYNC from being accidently exposed to a guest, : courtesy of Ben Horgan. From the cover letter: : : "The ID_AA64PFR1_EL1.MTE_frac field is currently hidden from KVM. : However, when ID_AA64PFR1_EL1.MTE==2, ID_AA64PFR1_EL1.MTE_frac==0 : indicates that MTE_ASYNC is supported. On a host with : ID_AA64PFR1_EL1.MTE==2 but without MTE_ASYNC support a guest with the : MTE capability enabled will incorrectly see MTE_ASYNC advertised as : supported. This series fixes that." : . KVM: selftests: Confirm exposing MTE_frac does not break migration KVM: arm64: Make MTE_frac masking conditional on MTE capability arm64/sysreg: Expose MTE_frac so that it is visible to KVM Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19KVM: arm64: Add sanitisation for FEAT_FGT2 registersMarc Zyngier
Just like the FEAT_FGT registers, treat the FGT2 variant the same way. THis is a large update, but a fairly mechanical one. The config dependencies are extracted from the 2025-03 JSON drop. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19KVM: arm64: nv: Plumb TLBI S1E2 into system instruction dispatchMarc Zyngier
Now that we have to handle TLBI S1E2 in the core code, plumb the sysinsn dispatch code into it, so that these instructions don't just UNDEF anymore. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250514103501.2225951-15-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19KVM: arm64: nv: Add userspace and guest handling of VNCR_EL2Marc Zyngier
Plug VNCR_EL2 in the vcpu_sysreg enum, define its RES0/RES1 bits, and make it accessible to userspace when the VM is configured to support FEAT_NV2. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250514103501.2225951-9-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19KVM: arm64: nv: Move TLBI range decoding to a helperMarc Zyngier
As we are about to expand out TLB invalidation capabilities to support recursive virtualisation, move the decoding of a TLBI by range into a helper that returns the base, the range and the ASID. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250514103501.2225951-6-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-16KVM: arm64: Make MTE_frac masking conditional on MTE capabilityBen Horgan
If MTE_frac is masked out unconditionally then the guest will always see ID_AA64PFR1_EL1_MTE_frac as 0. However, a value of 0 when ID_AA64PFR1_EL1_MTE is 2 indicates that MTE_ASYNC is supported. Hence, for a host with ID_AA64PFR1_EL1_MTE==2 and ID_AA64PFR1_EL1_MTE_frac==0xf (MTE_ASYNC unsupported) the guest would see MTE_ASYNC advertised as supported whilst the host does not support it. Hence, expose the sanitised value of MTE_frac to the guest and user-space. As MTE_frac was previously hidden, always 0, and KVM must accept values from KVM provided by user-space, when ID_AA64PFR1_EL1.MTE is 2 allow user-space to set ID_AA64PFR1_EL1.MTE_frac to 0. However, ignore it to avoid incorrectly claiming hardware support for MTE_ASYNC in the guest. Note that linux does not check the value of ID_AA64PFR1_EL1_MTE_frac and wrongly assumes that MTE async faults can be generated even on hardware that does nto support them. This issue is not addressed here. Signed-off-by: Ben Horgan <ben.horgan@arm.com> Link: https://lore.kernel.org/r/20250512114112.359087-3-ben.horgan@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-10KVM: arm64: Validate FGT register descriptions against RES0 masksMarc Zyngier
In order to point out to the unsuspecting KVM hacker that they are missing something somewhere, validate that the known FGT bits do not intersect with the corresponding RES0 mask, as computed at boot time. THis check is also performed at boot time, ensuring that there is no runtime overhead. Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-10KVM: arm64: Switch to table-driven FGU configurationMarc Zyngier
Defining the FGU behaviour is extremely tedious. It relies on matching each set of bits from FGT registers with am architectural feature, and adding them to the FGU list if the corresponding feature isn't advertised to the guest. It is however relatively easy to dump most of that information from the architecture JSON description, and use that to control the FGU bits. Let's introduce a new set of tables descripbing the mapping between FGT bits and features. Most of the time, this is only a lookup in an idreg field, with a few more complex exceptions. While this is obviously many more lines in a new file, this is mostly generated, and is pretty easy to maintain. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06KVM: arm64: Plug FEAT_GCS handlingMarc Zyngier
We don't seem to be handling the GCS-specific exception class. Handle it by delivering an UNDEF to the guest, and populate the relevant trap bits. Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06KVM: arm64: Restrict ACCDATA_EL1 undef to FEAT_LS64_ACCDATA being disabledMarc Zyngier
We currently unconditionally make ACCDATA_EL1 accesses UNDEF. As we are about to support it, restrict the UNDEF behaviour to cases where FEAT_LS64_ACCDATA is not exposed to the guest. Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06arm64: sysreg: Replace HFGxTR_EL2 with HFG{R,W}TR_EL2Marc Zyngier
Treating HFGRTR_EL2 and HFGWTR_EL2 identically was a mistake. It makes things hard to reason about, has the potential to introduce bugs by giving a meaning to bits that are really reserved, and is in general a bad description of the architecture. Given that #defines are cheap, let's describe both registers as intended by the architecture, and repaint all the existing uses. Yes, this is painful. The registers themselves are generated from the JSON file in an automated way. Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-05KVM: arm64: Prevent userspace from disabling AArch64 support at any ↵Marc Zyngier
virtualisable EL A sorry excuse for a selftest is trying to disable AArch64 support. And yes, this goes as well as you can imagine. Let's forbid this sort of things. Normal userspace shouldn't get caught doing that. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Link: https://lore.kernel.org/r/20250429114117.3618800-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-04-11KVM: arm64: Handle out-of-bound write to MDCR_EL2.HPMNMarc Zyngier
We don't really pay attention to what gets written to MDCR_EL2.HPMN, and funky guests could play ugly games on us. Restrict what gets written there, and limit the number of counters to what the PMU is allowed to have. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-04-11KVM: arm64: Don't let userspace write to PMCR_EL0.N when the vcpu has EL2Marc Zyngier
Now that userspace can provide its limit for hte maximum number of counters, prevent it from writing to PMCR_EL0.N, as the value should be derived from MDCR_EL2.HPMN in that case. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-04-11KVM: arm64: Fix MDCR_EL2.HPMN reset valueMarc Zyngier
The MDCR_EL2 documentation indicates that the HPMN field has the following behaviour: "On a Warm reset, this field resets to the expression NUM_PMU_COUNTERS." However, it appears we reset it to zero, which is not very useful. Add a reset helper for MDCR_EL2, and handle the case where userspace changes the target PMU, which may force us to change HPMN again. Reported-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-04-11KVM: arm64: Repaint pmcr_n into nr_pmu_countersMarc Zyngier
The pmcr_n field obviously refers to PMCR_EL0.N, but is generally used as the number of counters seen by the guest. Rename it accordingly. Suggested-by: Oliver upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-03-19Merge branch 'kvm-arm64/pmu-fixes' into kvmarm/nextOliver Upton
* kvm-arm64/pmu-fixes: : vPMU fixes for 6.15 courtesy of Akihiko Odaki : : Various fixes to KVM's vPMU implementation, notably ensuring : userspace-directed changes to the PMCs are reflected in the backing perf : events. KVM: arm64: PMU: Reload when resetting KVM: arm64: PMU: Reload when user modifies registers KVM: arm64: PMU: Fix SET_ONE_REG for vPMC regs KVM: arm64: PMU: Assume PMU presence in pmu-emul.c KVM: arm64: PMU: Set raw values from user to PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/pkvm-6.15' into kvmarm/nextOliver Upton
* kvm-arm64/pkvm-6.15: : pKVM updates for 6.15 : : - SecPageTable stats for stage-2 table pages allocated by the protected : hypervisor (Vincent Donnefort) : : - HCRX_EL2 trap + vCPU initialization fixes for pKVM (Fuad Tabba) KVM: arm64: Create each pKVM hyp vcpu after its corresponding host vcpu KVM: arm64: Factor out pKVM hyp vcpu creation to separate function KVM: arm64: Initialize HCRX_EL2 traps in pKVM KVM: arm64: Factor out setting HCRX_EL2 traps into separate function KVM: arm64: Count pKVM stage-2 usage in secondary pagetable stats KVM: arm64: Distinct pKVM teardown memcache for stage-2 KVM: arm64: Add flags to kvm_hyp_memcache Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/writable-midr' into kvmarm/nextOliver Upton
* kvm-arm64/writable-midr: : Writable implementation ID registers, courtesy of Sebastian Ott : : Introduce a new capability that allows userspace to set the : ID registers that identify a CPU implementation: MIDR_EL1, REVIDR_EL1, : and AIDR_EL1. Also plug a hole in KVM's trap configuration where : SMIDR_EL1 was readable at EL1, despite the fact that KVM does not : support SME. KVM: arm64: Fix documentation for KVM_CAP_ARM_WRITABLE_IMP_ID_REGS KVM: arm64: Copy MIDR_EL1 into hyp VM when it is writable KVM: arm64: Copy guest CTR_EL0 into hyp VM KVM: selftests: arm64: Test writes to MIDR,REVIDR,AIDR KVM: arm64: Allow userspace to change the implementation ID registers KVM: arm64: Load VPIDR_EL2 with the VM's MIDR_EL1 value KVM: arm64: Maintain per-VM copy of implementation ID regs KVM: arm64: Set HCR_EL2.TID1 unconditionally Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/nv-idregs' into kvmarm/nextOliver Upton
* kvm-arm64/nv-idregs: : Changes to exposure of NV features, courtesy of Marc Zyngier : : Apply NV-specific feature restrictions at reset rather than at the point : of KVM_RUN. This makes the true feature set visible to userspace, a : necessary step towards save/restore support or NV VMs. : : Add an additional vCPU feature flag for selecting the E2H0 flavor of NV, : such that the VHE-ness of the VM can be applied to the feature set. KVM: arm64: selftests: Test that TGRAN*_2 fields are writable KVM: arm64: Allow userspace to write ID_AA64MMFR0_EL1.TGRAN*_2 KVM: arm64: Advertise FEAT_ECV when possible KVM: arm64: Make ID_AA64MMFR4_EL1.NV_frac writable KVM: arm64: Allow userspace to limit NV support to nVHE KVM: arm64: Move NV-specific capping to idreg sanitisation KVM: arm64: Enforce NV limits on a per-idregs basis KVM: arm64: Make ID_REG_LIMIT_FIELD_ENUM() more widely available KVM: arm64: Consolidate idreg callbacks KVM: arm64: Advertise NV2 in the boot messages KVM: arm64: Mark HCR.EL2.{NV*,AT} RES0 when ID_AA64MMFR4_EL1.NV_frac is 0 KVM: arm64: Mark HCR.EL2.E2H RES0 when ID_AA64MMFR1_EL1.VH is zero KVM: arm64: Hide ID_AA64MMFR2_EL1.NV from guest and userspace arm64: cpufeature: Handle NV_frac as a synonym of NV2 Signed-off-by: Oliver Upton <oliver.upton@linux.dev>