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2025-06-02Merge tag 'kvmarm-fixes-6.16-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.16, take #1 - Make the irqbypass hooks resilient to changes in the GSI<->MSI routing, avoiding behind stale vLPI mappings being left behind. The fix is to resolve the VGIC IRQ using the host IRQ (which is stable) and nuking the vLPI mapping upon a routing change. - Close another VGIC race where vCPU creation races with VGIC creation, leading to in-flight vCPUs entering the kernel w/o private IRQs allocated. - Fix a build issue triggered by the recently added workaround for Ampere's AC04_CPU_23 erratum. - Correctly sign-extend the VA when emulating a TLBI instruction potentially targeting a VNCR mapping. - Avoid dereferencing a NULL pointer in the VGIC debug code, which can happen if the device doesn't have any mapping yet.
2025-05-30KVM: arm64: Unmap vLPIs affected by changes to GSI routing informationOliver Upton
KVM's interrupt infrastructure is dodgy at best, allowing for some ugly 'off label' usage of the various UAPIs. In one example, userspace can change the routing entry of a particular "GSI" after configuring irqbypass with KVM_IRQFD. KVM/arm64 is oblivious to this, and winds up preserving the stale translation in cases where vLPIs are configured. Honor userspace's intentions and tear down the vLPI mapping if affected by a "GSI" routing change. Make no attempt to reconstruct vLPIs if the new target is an MSI and just fall back to software injection. Tested-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250523194722.4066715-5-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-30KVM: arm64: Resolve vLPI by host IRQ in vgic_v4_unset_forwarding()Oliver Upton
The virtual mapping and "GSI" routing of a particular vLPI is subject to change in response to the guest / userspace. This can be pretty annoying to deal with when KVM needs to track the physical state that's managed for vLPI direct injection. Make vgic_v4_unset_forwarding() resilient by using the host IRQ to resolve the vgic IRQ. Since this uses the LPI xarray directly, finding the ITS by doorbell address + grabbing it's its_lock is no longer necessary. Note that matching the right ITS / ITE is already handled in vgic_v4_set_forwarding(), and unless there's a bug in KVM's VGIC ITS emulation the virtual mapping that should remain stable for the lifetime of the vLPI mapping. Tested-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250523194722.4066715-4-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-27KVM: arm64: use kvm_trylock_all_vcpus when locking all vCPUsMaxim Levitsky
Use kvm_trylock_all_vcpus instead of a custom implementation when locking all vCPUs of a VM, to avoid triggering a lockdep warning, in the case in which the VM is configured to have more than MAX_LOCK_DEPTH vCPUs. This fixes the following false lockdep warning: [ 328.171264] BUG: MAX_LOCK_DEPTH too low! [ 328.175227] turning off the locking correctness validator. [ 328.180726] Please attach the output of /proc/lock_stat to the bug report [ 328.187531] depth: 48 max: 48! [ 328.190678] 48 locks held by qemu-kvm/11664: [ 328.194957] #0: ffff800086de5ba0 (&kvm->lock){+.+.}-{3:3}, at: kvm_ioctl_create_device+0x174/0x5b0 [ 328.204048] #1: ffff0800e78800b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.212521] #2: ffff07ffeee51e98 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.220991] #3: ffff0800dc7d80b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.229463] #4: ffff07ffe0c980b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.237934] #5: ffff0800a3883c78 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 [ 328.246405] #6: ffff07fffbe480b8 (&vcpu->mutex){+.+.}-{3:3}, at: lock_all_vcpus+0x16c/0x2a0 Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Message-ID: <20250512180407.659015-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
2025-05-21Merge branch kvm-arm64/pkvm-selftest-6.16 into kvm-arm64/pkvm-np-thp-6.16Marc Zyngier
* kvm-arm64/pkvm-selftest-6.16: : . : pKVM selftests covering the memory ownership transitions by : Quentin Perret. From the initial cover letter: : : "We have recently found a bug [1] in the pKVM memory ownership : transitions by code inspection, but it could have been caught with a : test. : : Introduce a boot-time selftest exercising all the known pKVM memory : transitions and importantly checks the rejection of illegal transitions. : : The new test is hidden behind a new Kconfig option separate from : CONFIG_EL2_NVHE_DEBUG on purpose as that has side effects on the : transition checks ([1] doesn't reproduce with EL2 debug enabled). : : [1] https://lore.kernel.org/kvmarm/20241128154406.602875-1-qperret@google.com/" : . KVM: arm64: Extend pKVM selftest for np-guests KVM: arm64: Selftest for pKVM transitions KVM: arm64: Don't WARN from __pkvm_host_share_guest() KVM: arm64: Add .hyp.data section 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: Allow userspace to request KVM_ARM_VCPU_EL2*Marc Zyngier
Since we're (almost) feature complete, let's allow userspace to request KVM_ARM_VCPU_EL2* by bumping KVM_VCPU_MAX_FEATURES up. We also now advertise the features to userspace with new capabilities. It's going to be great... Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Link: https://lore.kernel.org/r/20250514103501.2225951-17-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19KVM: arm64: nv: Add pseudo-TLB backing VNCR_EL2Marc Zyngier
FEAT_NV2 introduces an interesting problem for NV, as VNCR_EL2.BADDR is a virtual address in the EL2&0 (or EL2, but we thankfully ignore this) translation regime. As we need to replicate such mapping in the real EL2, it means that we need to remember that there is such a translation, and that any TLBI affecting EL2 can possibly affect this translation. It also means that any invalidation driven by an MMU notifier must be able to shoot down any such mapping. All in all, we need a data structure that represents this mapping, and that is extremely close to a TLB. Given that we can only use one of those per vcpu at any given time, we only allocate one. No effort is made to keep that structure small. If we need to start caching multiple of them, we may want to revisit that design point. But for now, it is kept simple so that we can reason about it. Oh, and add a braindump of how things are supposed to work, because I will definitely page this out at some point. Yes, pun intended. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250514103501.2225951-8-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06KVM: arm64: Propagate FGT masks to the nVHE hypervisorMarc Zyngier
The nVHE hypervisor needs to have access to its own view of the FGT masks, which unfortunately results in a bit of data duplication. Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-06KVM: arm64: Add .hyp.data sectionDavid Brazdil
The hypervisor has not needed its own .data section because all globals were either .rodata or .bss. To avoid having to initialize future data-structures at run-time, let's introduce add a .data section to the hypervisor. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20250416160900.3078417-2-qperret@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-04-24KVM: arm64, x86: make kvm_arch_has_irq_bypass() inlinePaolo Bonzini
kvm_arch_has_irq_bypass() is a small function and even though it does not appear in any *really* hot paths, it's also not entirely rare. Make it inline---it also works out nicely in preparation for using it in kvm-intel.ko and kvm-amd.ko, since the function is not currently exported. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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/pmuv3-asahi' into kvmarm/nextOliver Upton
* kvm-arm64/pmuv3-asahi: : Support PMUv3 for KVM guests on Apple silicon : : Take advantage of some IMPLEMENTATION DEFINED traps available on Apple : parts to trap-and-emulate the PMUv3 registers on behalf of a KVM guest. : Constrain the vPMU to a cycle counter and single event counter, as the : Apple PMU has events that cannot be counted on every counter. : : There is a small new interface between the ARM PMU driver and KVM, where : the PMU driver owns the PMUv3 -> hardware event mappings. arm64: Enable IMP DEF PMUv3 traps on Apple M* KVM: arm64: Provide 1 event counter on IMPDEF hardware drivers/perf: apple_m1: Provide helper for mapping PMUv3 events KVM: arm64: Remap PMUv3 events onto hardware KVM: arm64: Advertise PMUv3 if IMPDEF traps are present KVM: arm64: Compute synthetic sysreg ESR for Apple PMUv3 traps KVM: arm64: Move PMUVer filtering into KVM code KVM: arm64: Use guard() to cleanup usage of arm_pmus_lock KVM: arm64: Drop kvm_arm_pmu_available static key KVM: arm64: Use a cpucap to determine if system supports FEAT_PMUv3 KVM: arm64: Always support SW_INCR PMU event KVM: arm64: Compute PMCEID from arm_pmu's event bitmaps drivers/perf: apple_m1: Support host/guest event filtering drivers/perf: apple_m1: Refactor event select/filter configuration 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>
2025-03-19Merge branch 'kvm-arm64/nv-vgic' into kvmarm/nextOliver Upton
* kvm-arm64/nv-vgic: : NV VGICv3 support, courtesy of Marc Zyngier : : Support for emulating the GIC hypervisor controls and managing shadow : VGICv3 state for the L1 hypervisor. As part of it, bring in support for : taking IRQs to the L1 and UAPI to manage the VGIC maintenance interrupt. KVM: arm64: nv: Fail KVM init if asking for NV without GICv3 KVM: arm64: nv: Allow userland to set VGIC maintenance IRQ KVM: arm64: nv: Fold GICv3 host trapping requirements into guest setup KVM: arm64: nv: Propagate used_lrs between L1 and L0 contexts KVM: arm64: nv: Request vPE doorbell upon nested ERET to L2 KVM: arm64: nv: Respect virtual HCR_EL2.TWx setting KVM: arm64: nv: Add Maintenance Interrupt emulation KVM: arm64: nv: Handle L2->L1 transition on interrupt injection KVM: arm64: nv: Nested GICv3 emulation KVM: arm64: nv: Sanitise ICH_HCR_EL2 accesses KVM: arm64: nv: Plumb handling of GICv3 EL2 accesses KVM: arm64: nv: Add ICH_*_EL2 registers to vpcu_sysreg KVM: arm64: nv: Load timer before the GIC arm64: sysreg: Add layout for ICH_MISR_EL2 arm64: sysreg: Add layout for ICH_VTR_EL2 arm64: sysreg: Add layout for ICH_HCR_EL2 Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/misc' into kvmarm/nextOliver Upton
* kvm-arm64/misc: : Miscellaneous fixes/cleanups for KVM/arm64 : : - Avoid GICv4 vLPI configuration when confronted with user error : : - Only attempt vLPI configuration when the target routing is an MSI : : - Document ordering requirements to avoid aforementioned user error KVM: arm64: Tear down vGIC on failed vCPU creation KVM: arm64: Document ordering requirements for irqbypass KVM: arm64: vgic-v4: Fall back to software irqbypass if LPI not found KVM: arm64: vgic-v4: Only WARN for HW IRQ mismatch when unmapping vLPI KVM: arm64: vgic-v4: Only attempt vLPI mapping for actual MSIs Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-17KVM: arm64: Tear down vGIC on failed vCPU creationWill Deacon
If kvm_arch_vcpu_create() fails to share the vCPU page with the hypervisor, we propagate the error back to the ioctl but leave the vGIC vCPU data initialised. Note only does this leak the corresponding memory when the vCPU is destroyed but it can also lead to use-after-free if the redistributor device handling tries to walk into the vCPU. Add the missing cleanup to kvm_arch_vcpu_create(), ensuring that the vGIC vCPU structures are destroyed on error. Cc: <stable@vger.kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250314133409.9123-1-will@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-17KVM: arm64: PMU: Assume PMU presence in pmu-emul.cAkihiko Odaki
Many functions in pmu-emul.c checks kvm_vcpu_has_pmu(vcpu). A favorable interpretation is defensive programming, but it also has downsides: - It is confusing as it implies these functions are called without PMU although most of them are called only when a PMU is present. - It makes semantics of functions fuzzy. For example, calling kvm_pmu_disable_counter_mask() without PMU may result in no-op as there are no enabled counters, but it's unclear what kvm_pmu_get_counter_value() returns when there is no PMU. - It allows callers without checking kvm_vcpu_has_pmu(vcpu), but it is often wrong to call these functions without PMU. - It is error-prone to duplicate kvm_vcpu_has_pmu(vcpu) checks into multiple functions. Many functions are called for system registers, and the system register infrastructure already employs less error-prone, comprehensive checks. Check kvm_vcpu_has_pmu(vcpu) in callers of these functions instead, and remove the obsolete checks from pmu-emul.c. The only exceptions are the functions that implement ioctls as they have definitive semantics even when the PMU is not present. Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250315-pmc-v5-2-ecee87dab216@daynix.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-14KVM: arm64: Create each pKVM hyp vcpu after its corresponding host vcpuFuad Tabba
Instead of creating and initializing _all_ hyp vcpus in pKVM when the first host vcpu runs for the first time, initialize _each_ hyp vcpu in conjunction with its corresponding host vcpu. Some of the host vcpu state (e.g., system registers and traps values) is not initialized until the first time the host vcpu is run. Therefore, initializing a hyp vcpu before its corresponding host vcpu has run for the first time might not view the complete host state of these vcpus. Additionally, this behavior is inline with non-protected modes. Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20250314111832.4137161-5-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-11KVM: arm64: Drop kvm_arm_pmu_available static keyOliver Upton
With the PMUv3 cpucap, kvm_arm_pmu_available is no longer used in the hot path of guest entry/exit. On top of that, guest support for PMUv3 may not correlate with host support for the feature, e.g. on IMPDEF hardware. Throw out the static key and just inspect the list of PMUs to determine if PMUv3 is supported for KVM guests. Tested-by: Janne Grunau <j@jannau.net> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250305202641.428114-7-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03KVM: arm64: nv: Fail KVM init if asking for NV without GICv3Marc Zyngier
Although there is nothing in NV that is fundamentally incompatible with the lack of GICv3, there is no HW implementation without one, at least on the virtual side (yes, even fruits have some form of vGICv3). We therefore make the decision to require GICv3, which will only affect models such as QEMU. Booting with a GICv2 or something even more exotic while asking for NV will result in KVM being disabled. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-17-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03KVM: arm64: nv: Add Maintenance Interrupt emulationMarc Zyngier
Emulating the vGIC means emulating the dreaded Maintenance Interrupt. This is a two-pronged problem: - while running L2, getting an MI translates into an MI injected in the L1 based on the state of the HW. - while running L1, we must accurately reflect the state of the MI line, based on the in-memory state. The MI INTID is added to the distributor, as expected on any virtualisation-capable implementation, and further patches will allow its configuration. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-11-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03KVM: arm64: nv: Handle L2->L1 transition on interrupt injectionMarc Zyngier
An interrupt being delivered to L1 while running L2 must result in the correct exception being delivered to L1. This means that if, on entry to L2, we found ourselves with pending interrupts in the L1 distributor, we need to take immediate action. This is done by posting a request which will prevent the entry in L2, and deliver an IRQ exception to L1, forcing the switch. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-10-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03KVM: arm64: nv: Load timer before the GICMarc Zyngier
In order for vgic_v3_load_nested to be able to observe which timer interrupts have the HW bit set for the current context, the timers must have been loaded in the new mode and the right timer mapped to their corresponding HW IRQs. At the moment, we load the GIC first, meaning that timer interrupts injected to an L2 guest will never have the HW bit set (we see the old configuration). Swapping the two loads solves this particular problem. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-5-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26KVM: arm64: vgic-v4: Only attempt vLPI mapping for actual MSIsOliver Upton
Some 'creative' VMMs out there may assign a VFIO MSI eventfd to an SPI routing entry. And yes, I can already hear you shouting about possibly driving a level interrupt with an edge-sensitive one. You know who you are. This works for the most part, and interrupt injection winds up taking the software path. However, when running on GICv4-enabled hardware, KVM erroneously attempts to setup LPI forwarding, even though the KVM routing isn't an MSI. Thanks to misuse of a union, the MSI destination is unlikely to match any ITS in the VM and kvm_vgic_v4_set_forwarding() bails early. Later on when the VM is being torn down, this half-configured state triggers the WARN_ON() in kvm_vgic_v4_unset_forwarding() due to the fact that no HW IRQ was ever assigned. Avoid the whole mess by preventing SPI routing entries from getting into the LPI forwarding helpers. Reported-by: Sudheer Dantuluri <dantuluris@google.com> Tested-by: Sudheer Dantuluri <dantuluris@google.com> Fixes: 196b136498b3 ("KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass") Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250226183124.82094-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26KVM: arm64: Allow userspace to change the implementation ID registersSebastian Ott
KVM's treatment of the ID registers that describe the implementation (MIDR, REVIDR, and AIDR) is interesting, to say the least. On the userspace-facing end of it, KVM presents the values of the boot CPU on all vCPUs and treats them as invariant. On the guest side of things KVM presents the hardware values of the local CPU, which can change during CPU migration in a big-little system. While one may call this fragile, there is at least some degree of predictability around it. For example, if a VMM wanted to present big-little to a guest, it could affine vCPUs accordingly to the correct clusters. All of this makes a giant mess out of adding support for making these implementation ID registers writable. Avoid breaking the rather subtle ABI around the old way of doing things by requiring opt-in from userspace to make the registers writable. When the cap is enabled, allow userspace to set MIDR, REVIDR, and AIDR to any non-reserved value and present those values consistently across all vCPUs. Signed-off-by: Sebastian Ott <sebott@redhat.com> [oliver: changelog, capability] Link: https://lore.kernel.org/r/20250225005401.679536-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-24KVM: arm64: Advertise NV2 in the boot messagesMarc Zyngier
Make it a bit easier to understand what people are running by adding a +NV2 string to the successful KVM initialisation. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20250220134907.554085-6-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-20KVM: arm64: Ensure a VMID is allocated before programming VTTBR_EL2Oliver Upton
Vladimir reports that a race condition to attach a VMID to a stage-2 MMU sometimes results in a vCPU entering the guest with a VMID of 0: | CPU1 | CPU2 | | | | kvm_arch_vcpu_ioctl_run | | vcpu_load <= load VTTBR_EL2 | | kvm_vmid->id = 0 | | | kvm_arch_vcpu_ioctl_run | | vcpu_load <= load VTTBR_EL2 | | with kvm_vmid->id = 0| | kvm_arm_vmid_update <= allocates fresh | | kvm_vmid->id and | | reload VTTBR_EL2 | | | | | kvm_arm_vmid_update <= observes that kvm_vmid->id | | already allocated, | | skips reload VTTBR_EL2 Oh yeah, it's as bad as it looks. Remember that VHE loads the stage-2 MMU eagerly but a VMID only gets attached to the MMU later on in the KVM_RUN loop. Even in the "best case" where VTTBR_EL2 correctly gets reprogrammed before entering the EL1&0 regime, there is a period of time where hardware is configured with VMID 0. That's completely insane. So, rather than decorating the 'late' binding with another hack, just allocate the damn thing up front. Attaching a VMID from vcpu_load() is still rollover safe since (surprise!) it'll always get called after a vCPU was preempted. Excuse me while I go find a brown paper bag. Cc: stable@vger.kernel.org Fixes: 934bf871f011 ("KVM: arm64: Load the stage-2 MMU context in kvm_vcpu_load_vhe()") Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250219220737.130842-1-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-02-19KVM: arm64: Fix tcr_el2 initialisation in hVHE modeWill Deacon
When not running in VHE mode, cpu_prepare_hyp_mode() computes the value of TCR_EL2 using the host's TCR_EL1 settings as a starting point. For nVHE, this amounts to masking out everything apart from the TG0, SH0, ORGN0, IRGN0 and T0SZ fields before setting the RES1 bits, shifting the IPS field down to the PS field and setting DS if LPA2 is enabled. Unfortunately, for hVHE, things go slightly wonky: EPD1 is correctly set to disable walks via TTBR1_EL2 but then the T1SZ and IPS fields are corrupted when we mistakenly attempt to initialise the PS and DS fields in their E2H=0 positions. Furthermore, many fields are retained from TCR_EL1 which should not be propagated to TCR_EL2. Notably, this means we can end up with A1 set despite not initialising TTBR1_EL2 at all. This has been shown to cause unexpected translation faults at EL2 with pKVM due to TLB invalidation not taking effect when running with a non-zero ASID. Fix the TCR_EL2 initialisation code to set PS and DS only when E2H=0, masking out HD, HA and A1 when E2H=1. Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Fixes: ad744e8cb346 ("arm64: Allow arm64_sw.hvhe on command line") Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250214133724.13179-1-will@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-02-14Merge tag 'kvmarm-fixes-6.14-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.14, take #2 - Large set of fixes for vector handling, specially in the interactions between host and guest state. This fixes a number of bugs affecting actual deployments, and greatly simplifies the FP/SIMD/SVE handling. Thanks to Mark Rutland for dealing with this thankless task. - Fix an ugly race between vcpu and vgic creation/init, resulting in unexpected behaviours. - Fix use of kernel VAs at EL2 when emulating timers with nVHE. - Small set of pKVM improvements and cleanups.
2025-02-13KVM: arm64: Remove host FPSIMD saving for non-protected KVMMark Rutland
Now that the host eagerly saves its own FPSIMD/SVE/SME state, non-protected KVM never needs to save the host FPSIMD/SVE/SME state, and the code to do this is never used. Protected KVM still needs to save/restore the host FPSIMD/SVE state to avoid leaking guest state to the host (and to avoid revealing to the host whether the guest used FPSIMD/SVE/SME), and that code needs to be retained. Remove the unused code and data structures. To avoid the need for a stub copy of kvm_hyp_save_fpsimd_host() in the VHE hyp code, the nVHE/hVHE version is moved into the shared switch header, where it is only invoked when KVM is in protected mode. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Tested-by: Mark Brown <broonie@kernel.org> Acked-by: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Fuad Tabba <tabba@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250210195226.1215254-3-mark.rutland@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-02-04Merge tag 'kvmarm-fixes-6.14-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.14, take #1 - Correctly clean the BSS to the PoC before allowing EL2 to access it on nVHE/hVHE/protected configurations - Propagate ownership of debug registers in protected mode after the rework that landed in 6.14-rc1 - Stop pretending that we can run the protected mode without a GICv3 being present on the host - Fix a use-after-free situation that can occur if a vcpu fails to initialise the NV shadow S2 MMU contexts - Always evaluate the need to arm a background timer for fully emulated guest timers - Fix the emulation of EL1 timers in the absence of FEAT_ECV - Correctly handle the EL2 virtual timer, specially when HCR_EL2.E2H==0
2025-02-04KVM: arm64: Fail protected mode init if no vgic hardware is presentOliver Upton
Protected mode assumes that at minimum vgic-v3 is present, however KVM fails to actually enforce this at the time of initialization. As such, when running protected mode in a half-baked state on GICv2 hardware we see the hyp go belly up at vcpu_load() when it tries to restore the vgic-v3 cpuif: $ ./arch_timer_edge_cases [ 130.599140] kvm [4518]: nVHE hyp panic at: [<ffff800081102b58>] __kvm_nvhe___vgic_v3_restore_vmcr_aprs+0x8/0x84! [ 130.603685] kvm [4518]: Cannot dump pKVM nVHE stacktrace: !CONFIG_PROTECTED_NVHE_STACKTRACE [ 130.611962] kvm [4518]: Hyp Offset: 0xfffeca95ed000000 [ 130.617053] Kernel panic - not syncing: HYP panic: [ 130.617053] PS:800003c9 PC:0000b56a94102b58 ESR:0000000002000000 [ 130.617053] FAR:ffff00007b98d4d0 HPFAR:00000000007b98d0 PAR:0000000000000000 [ 130.617053] VCPU:0000000000000000 [ 130.638013] CPU: 0 UID: 0 PID: 4518 Comm: arch_timer_edge Tainted: G C 6.13.0-rc3-00009-gf7d03fcbf1f4 #1 [ 130.648790] Tainted: [C]=CRAP [ 130.651721] Hardware name: Libre Computer AML-S905X-CC (DT) [ 130.657242] Call trace: [ 130.659656] show_stack+0x18/0x24 (C) [ 130.663279] dump_stack_lvl+0x38/0x90 [ 130.666900] dump_stack+0x18/0x24 [ 130.670178] panic+0x388/0x3e8 [ 130.673196] nvhe_hyp_panic_handler+0x104/0x208 [ 130.677681] kvm_arch_vcpu_load+0x290/0x548 [ 130.681821] vcpu_load+0x50/0x80 [ 130.685013] kvm_arch_vcpu_ioctl_run+0x30/0x868 [ 130.689498] kvm_vcpu_ioctl+0x2e0/0x974 [ 130.693293] __arm64_sys_ioctl+0xb4/0xec [ 130.697174] invoke_syscall+0x48/0x110 [ 130.700883] el0_svc_common.constprop.0+0x40/0xe0 [ 130.705540] do_el0_svc+0x1c/0x28 [ 130.708818] el0_svc+0x30/0xd0 [ 130.711837] el0t_64_sync_handler+0x10c/0x138 [ 130.716149] el0t_64_sync+0x198/0x19c [ 130.719774] SMP: stopping secondary CPUs [ 130.723660] Kernel Offset: disabled [ 130.727103] CPU features: 0x000,00000800,02800000,0200421b [ 130.732537] Memory Limit: none [ 130.735561] ---[ end Kernel panic - not syncing: HYP panic: [ 130.735561] PS:800003c9 PC:0000b56a94102b58 ESR:0000000002000000 [ 130.735561] FAR:ffff00007b98d4d0 HPFAR:00000000007b98d0 PAR:0000000000000000 [ 130.735561] VCPU:0000000000000000 ]--- Fix it by failing KVM initialization if the system doesn't implement vgic-v3, as protected mode will never do anything useful on such hardware. Reported-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/kvmarm/5ca7588c-7bf2-4352-8661-e4a56a9cd9aa@sirena.org.uk/ Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250203231543.233511-1-oliver.upton@linux.dev Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-28Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull KVM/arm64 updates from Will Deacon: "New features: - Support for non-protected guest in protected mode, achieving near feature parity with the non-protected mode - Support for the EL2 timers as part of the ongoing NV support - Allow control of hardware tracing for nVHE/hVHE Improvements, fixes and cleanups: - Massive cleanup of the debug infrastructure, making it a bit less awkward and definitely easier to maintain. This should pave the way for further optimisations - Complete rewrite of pKVM's fixed-feature infrastructure, aligning it with the rest of KVM and making the code easier to follow - Large simplification of pKVM's memory protection infrastructure - Better handling of RES0/RES1 fields for memory-backed system registers - Add a workaround for Qualcomm's Snapdragon X CPUs, which suffer from a pretty nasty timer bug - Small collection of cleanups and low-impact fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (87 commits) arm64/sysreg: Get rid of TRFCR_ELx SysregFields KVM: arm64: nv: Fix doc header layout for timers KVM: arm64: nv: Apply RESx settings to sysreg reset values KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessors KVM: arm64: Fix selftests after sysreg field name update coresight: Pass guest TRFCR value to KVM KVM: arm64: Support trace filtering for guests KVM: arm64: coresight: Give TRBE enabled state to KVM coresight: trbe: Remove redundant disable call arm64/sysreg/tools: Move TRFCR definitions to sysreg tools: arm64: Update sysreg.h header files KVM: arm64: Drop pkvm_mem_transition for host/hyp donations KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing KVM: arm64: Drop pkvm_mem_transition for FF-A KVM: arm64: Explicitly handle BRBE traps as UNDEFINED KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe() arm64: kvm: Introduce nvhe stack size constants KVM: arm64: Fix nVHE stacktrace VA bits mask KVM: arm64: Fix FEAT_MTE in pKVM Documentation: Update the behaviour of "kvm-arm.mode" ...
2025-01-21KVM: arm64: Flush hyp bss section after initialization of variables in bssLokesh Vutla
To determine CPU features during initialization, the nVHE hypervisor utilizes sanitized values of the host's CPU features registers. These values, stored in u64 idaa64*_el1_sys_val variables are updated by the kvm_hyp_init_symbols() function at EL1. To ensure EL2 visibility with the MMU off, the data cache needs to be flushed after these updates. However, individually flushing each variable using kvm_flush_dcache_to_poc() is inefficient. These cpu feature variables would be part of the bss section of the hypervisor. Hence, flush the entire bss section of hypervisor once the initialization is complete. Fixes: 6c30bfb18d0b ("KVM: arm64: Add handlers for protected VM System Registers") Suggested-by: Fuad Tabba <tabba@google.com> Signed-off-by: Lokesh Vutla <lokeshvutla@google.com> Link: https://lore.kernel.org/r/20250121044016.2219256-1-lokeshvutla@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-17Merge branch kvm-arm64/misc-6.14 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/misc-6.14: : . : Misc KVM/arm64 changes for 6.14 : : - Don't expose AArch32 EL0 capability when NV is enabled : : - Update documentation to reflect the full gamut of kvm-arm.mode : behaviours : : - Use the hypervisor VA bit width when dumping stacktraces : : - Decouple the hypervisor stack size from PAGE_SIZE, at least : on the surface... : : - Make use of str_enabled_disabled() when advertising GICv4.1 support : : - Explicitly handle BRBE traps as UNDEFINED : . KVM: arm64: Explicitly handle BRBE traps as UNDEFINED KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe() arm64: kvm: Introduce nvhe stack size constants KVM: arm64: Fix nVHE stacktrace VA bits mask Documentation: Update the behaviour of "kvm-arm.mode" KVM: arm64: nv: Advertise the lack of AArch32 EL0 support Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-17Merge branch kvm-arm64/nv-timers into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-timers: : . : Nested Virt support for the EL2 timers. From the initial cover letter: : : "Here's another batch of NV-related patches, this time bringing in most : of the timer support for EL2 as well as nested guests. : : The code is pretty convoluted for a bunch of reasons: : : - FEAT_NV2 breaks the timer semantics by redirecting HW controls to : memory, meaning that a guest could setup a timer and never see it : firing until the next exit : : - We go try hard to reflect the timer state in memory, but that's not : great. : : - With FEAT_ECV, we can finally correctly emulate the virtual timer, : but this emulation is pretty costly : : - As a way to make things suck less, we handle timer reads as early as : possible, and only defer writes to the normal trap handling : : - Finally, some implementations are badly broken, and require some : hand-holding, irrespective of NV support. So we try and reuse the NV : infrastructure to make them usable. This could be further optimised, : but I'm running out of patience for this sort of HW. : : [...]" : . KVM: arm64: nv: Fix doc header layout for timers KVM: arm64: nv: Document EL2 timer API KVM: arm64: Work around x1e's CNTVOFF_EL2 bogosity KVM: arm64: nv: Sanitise CNTHCTL_EL2 KVM: arm64: nv: Propagate CNTHCTL_EL2.EL1NV{P,V}CT bits KVM: arm64: nv: Add trap routing for CNTHCTL_EL2.EL1{NVPCT,NVVCT,TVT,TVCT} KVM: arm64: Handle counter access early in non-HYP context KVM: arm64: nv: Accelerate EL0 counter accesses from hypervisor context KVM: arm64: nv: Accelerate EL0 timer read accesses when FEAT_ECV in use KVM: arm64: nv: Use FEAT_ECV to trap access to EL0 timers KVM: arm64: nv: Publish emulated timer interrupt state in the in-memory state KVM: arm64: nv: Sync nested timer state with FEAT_NV2 KVM: arm64: nv: Add handling of EL2-specific timer registers Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-12Merge branch kvm-arm64/pkvm-fixed-features-6.14 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/pkvm-fixed-features-6.14: (24 commits) : . : Complete rework of the pKVM handling of features, catching up : with the rest of the code deals with it these days. : Patches courtesy of Fuad Tabba. From the cover letter: : : "This patch series uses the vm's feature id registers to track the : supported features, a framework similar to nested virt to set the : trap values, and removes the need to store cptr_el2 per vcpu in : favor of setting its value when traps are activated, as VHE mode : does." : : This branch drags the arm64/for-next/cpufeature branch to solve : ugly conflicts in -next. : . KVM: arm64: Fix FEAT_MTE in pKVM KVM: arm64: Use kvm_vcpu_has_feature() directly for struct kvm KVM: arm64: Convert the SVE guest vcpu flag to a vm flag KVM: arm64: Remove PtrAuth guest vcpu flag KVM: arm64: Fix the value of the CPTR_EL2 RES1 bitmask for nVHE KVM: arm64: Refactor kvm_reset_cptr_el2() KVM: arm64: Calculate cptr_el2 traps on activating traps KVM: arm64: Remove redundant setting of HCR_EL2 trap bit KVM: arm64: Remove fixed_config.h header KVM: arm64: Rework specifying restricted features for protected VMs KVM: arm64: Set protected VM traps based on its view of feature registers KVM: arm64: Fix RAS trapping in pKVM for protected VMs KVM: arm64: Initialize feature id registers for protected VMs KVM: arm64: Use KVM extension checks for allowed protected VM capabilities KVM: arm64: Remove KVM_ARM_VCPU_POWER_OFF from protected VMs allowed features in pKVM KVM: arm64: Move checking protected vcpu features to a separate function KVM: arm64: Group setting traps for protected VMs by control register KVM: arm64: Consolidate allowed and restricted VM feature checks arm64/sysreg: Get rid of CPACR_ELx SysregFields arm64/sysreg: Convert *_EL12 accessors to Mapping ... Signed-off-by: Marc Zyngier <maz@kernel.org> # Conflicts: # arch/arm64/kvm/fpsimd.c # arch/arm64/kvm/hyp/nvhe/pkvm.c
2025-01-12Merge branch kvm-arm64/pkvm-np-guest into kvmarm-master/nextMarc Zyngier
* kvm-arm64/pkvm-np-guest: : . : pKVM support for non-protected guests using the standard MM : infrastructure, courtesy of Quentin Perret. From the cover letter: : : "This series moves the stage-2 page-table management of non-protected : guests to EL2 when pKVM is enabled. This is only intended as an : incremental step towards a 'feature-complete' pKVM, there is however a : lot more that needs to come on top. : : With that series applied, pKVM provides near-parity with standard KVM : from a functional perspective all while Linux no longer touches the : stage-2 page-tables itself at EL1. The majority of mm-related KVM : features work out of the box, including MMU notifiers, dirty logging, : RO memslots and things of that nature. There are however two gotchas: : : - We don't support mapping devices into guests: this requires : additional hypervisor support for tracking the 'state' of devices, : which will come in a later series. No device assignment until then. : : - Stage-2 mappings are forced to page-granularity even when backed by a : huge page for the sake of simplicity of this series. I'm only aiming : at functional parity-ish (from userspace's PoV) for now, support for : HP can be added on top later as a perf improvement." : . KVM: arm64: Plumb the pKVM MMU in KVM KVM: arm64: Introduce the EL1 pKVM MMU KVM: arm64: Introduce __pkvm_tlb_flush_vmid() KVM: arm64: Introduce __pkvm_host_mkyoung_guest() KVM: arm64: Introduce __pkvm_host_test_clear_young_guest() KVM: arm64: Introduce __pkvm_host_wrprotect_guest() KVM: arm64: Introduce __pkvm_host_relax_guest_perms() KVM: arm64: Introduce __pkvm_host_unshare_guest() KVM: arm64: Introduce __pkvm_host_share_guest() KVM: arm64: Introduce __pkvm_vcpu_{load,put}() KVM: arm64: Add {get,put}_pkvm_hyp_vm() helpers KVM: arm64: Make kvm_pgtable_stage2_init() a static inline function KVM: arm64: Pass walk flags to kvm_pgtable_stage2_relax_perms KVM: arm64: Pass walk flags to kvm_pgtable_stage2_mkyoung KVM: arm64: Move host page ownership tracking to the hyp vmemmap KVM: arm64: Make hyp_page::order a u8 KVM: arm64: Move enum pkvm_page_state to memory.h KVM: arm64: Change the layout of enum pkvm_page_state Signed-off-by: Marc Zyngier <maz@kernel.org> # Conflicts: # arch/arm64/kvm/arm.c
2025-01-08arm64: kvm: Introduce nvhe stack size constantsKalesh Singh
Refactor nvhe stack code to use NVHE_STACK_SIZE/SHIFT constants, instead of directly using PAGE_SIZE/SHIFT. This makes the code a bit easier to read, without introducing any functional changes. Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Link: https://lore.kernel.org/r/20241112003336.1375584-1-kaleshsingh@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-02KVM: arm64: nv: Publish emulated timer interrupt state in the in-memory stateMarc Zyngier
With FEAT_NV2, the EL0 timer state is entirely stored in memory, meaning that the hypervisor can only provide a very poor emulation. The only thing we can really do is to publish the interrupt state in the guest view of CNT{P,V}_CTL_EL0, and defer everything else to the next exit. Only FEAT_ECV will allow us to fix it, at the cost of extra trapping. Suggested-by: Chase Conklin <chase.conklin@arm.com> Suggested-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20241217142321.763801-4-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-02KVM: arm64: nv: Sync nested timer state with FEAT_NV2Marc Zyngier
Emulating the timers with FEAT_NV2 is a bit odd, as the timers can be reconfigured behind our back without the hypervisor even noticing. In the VHE case, that's an actual regression in the architecture... Co-developed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20241217142321.763801-3-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Calculate cptr_el2 traps on activating trapsFuad Tabba
Similar to VHE, calculate the value of cptr_el2 from scratch on activate traps. This removes the need to store cptr_el2 in every vcpu structure. Moreover, some traps, such as whether the guest owns the fp registers, need to be set on every vcpu run. Reported-by: James Clark <james.clark@linaro.org> Fixes: 5294afdbf45a ("KVM: arm64: Exclude FP ownership from kvm_vcpu_arch") Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-13-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Use KVM extension checks for allowed protected VM capabilitiesFuad Tabba
Use KVM extension checks as the source for determining which capabilities are allowed for protected VMs. KVM extension checks is the natural place for this, since it is also the interface exposed to users. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-6-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Plumb the pKVM MMU in KVMQuentin Perret
Introduce the KVM_PGT_CALL() helper macro to allow switching from the traditional pgtable code to the pKVM version easily in mmu.c. The cost of this 'indirection' is expected to be very minimal due to is_protected_kvm_enabled() being backed by a static key. With this, everything is in place to allow the delegation of non-protected guest stage-2 page-tables to pKVM, so let's stop using the host's kvm_s2_mmu from EL2 and enjoy the ride. Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20241218194059.3670226-19-qperret@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Introduce __pkvm_vcpu_{load,put}()Marc Zyngier
Rather than look-up the hyp vCPU on every run hypercall at EL2, introduce a per-CPU 'loaded_hyp_vcpu' tracking variable which is updated by a pair of load/put hypercalls called directly from kvm_arch_vcpu_{load,put}() when pKVM is enabled. Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20241218194059.3670226-10-qperret@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>