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2025-04-03KVM: arm64: Don't translate FAR if invalid/unsafeOliver Upton
Don't re-walk the page tables if an SEA occurred during the faulting page table walk to avoid taking a fatal exception in the hyp. Additionally, check that FAR_EL2 is valid for SEAs not taken on PTW as the architecture doesn't guarantee it contains the fault VA. Finally, fix up the rest of the abort path by checking for SEAs early and bugging the VM if we get further along with an UNKNOWN fault IPA. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250402201725.2963645-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-04-03arm64: Convert HPFAR_EL2 to sysreg tableOliver Upton
Switch over to the typical sysreg table for HPFAR_EL2 as we're about to start using more fields in the register. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250402201725.2963645-3-oliver.upton@linux.dev 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>
2025-03-14KVM: arm64: Factor out setting HCRX_EL2 traps into separate functionFuad Tabba
Factor out the code for setting a vcpu's HCRX_EL2 traps in to a separate inline function. This allows us to share the logic with pKVM when setting the traps in protected mode. No functional change intended. Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20250314111832.4137161-2-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03KVM: arm64: nv: Respect virtual HCR_EL2.TWx settingJintack Lim
Forward exceptions due to WFI or WFE instructions to the virtual EL2 if they are not coming from the virtual EL2 and virtual HCR_EL2.TWx is set. Signed-off-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-12-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-13KVM: arm64: Refactor CPTR trap deactivationMark Rutland
For historical reasons, the VHE and nVHE/hVHE implementations of __activate_cptr_traps() pair with a common implementation of __kvm_reset_cptr_el2(), which ideally would be named __deactivate_cptr_traps(). Rename __kvm_reset_cptr_el2() to __deactivate_cptr_traps(), and split it into separate VHE and nVHE/hVHE variants so that each can be paired with its corresponding implementation of __activate_cptr_traps(). At the same time, fold kvm_write_cptr_el2() into its callers. This makes it clear in-context whether a write is made to the CPACR_EL1 encoding or the CPTR_EL2 encoding, and removes the possibility of confusion as to whether kvm_write_cptr_el2() reformats the sysreg fields as cpacr_clear_set() does. In the nVHE/hVHE implementation of __activate_cptr_traps(), placing the sysreg writes within the if-else blocks requires that the call to __activate_traps_fpsimd32() is moved earlier, but as this was always called before writing to CPTR_EL2/CPACR_EL1, this should not result in a functional change. 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/20250210195226.1215254-6-mark.rutland@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-17Merge branch kvm-arm64/nv-resx-fixes-6.14 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-resx-fixes-6.14: : . : Fixes for NV sysreg accessors. From the cover letter: : : "Joey recently reported that some rather basic tests were failing on : NV, and managed to track it down to critical register fields (such as : HCR_EL2.E2H) not having their expect value. : : Further investigation has outlined a couple of critical issues: : : - Evaluating HCR_EL2.E2H must always be done with a sanitising : accessor, no ifs, no buts. Given that KVM assumes a fixed value for : this bit, we cannot leave it to the guest to mess with. : : - Resetting the sysreg file must result in the RESx bits taking : effect. Otherwise, we may end-up making the wrong decision (see : above), and we definitely expose invalid values to the guest. Note : that because we compute the RESx masks very late in the VM setup, we : need to apply these masks at that particular point as well. : [...]" : . KVM: arm64: nv: Apply RESx settings to sysreg reset values KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessors Signed-off-by: Marc Zyngier <maz@kernel.org> # Conflicts: # arch/arm64/kvm/nested.c
2025-01-14KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessorsMarc Zyngier
A lot of the NV code depends on HCR_EL2.{E2H,TGE}, and we assume in places that at least HCR_EL2.E2H is invariant for a given guest. However, we make a point in *not* using the sanitising accessor that would enforce this, and are at the mercy of the guest doing stupid things. Clearly, that's not good. Rework the HCR_EL2 accessors to use __vcpu_sys_reg() instead, guaranteeing that the RESx settings get applied, specially when HCR_EL2.E2H is evaluated. This results in fewer accessors overall. Huge thanks to Joey who spent a long time tracking this bug down. Reported-by: Joey Gouly <Joey.Gouly@arm.com> Tested-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20250112165029.1181056-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-11Merge remote-tracking branch 'arm64/for-next/cpufeature' into ↵Marc Zyngier
kvm-arm64/pkvm-fixed-features-6.14 Merge arm64/for-next/cpufeature to solve extensive conflicts caused by the CPACR_ELx->CPACR_EL1 repainting. Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Convert the SVE guest vcpu flag to a vm flagFuad Tabba
The vcpu flag GUEST_HAS_SVE is per-vcpu, but it is based on what is now a per-vm feature. Make the flag per-vm. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-17-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Remove PtrAuth guest vcpu flagFuad Tabba
The vcpu flag GUEST_HAS_PTRAUTH is always associated with the vcpu PtrAuth features, which are defined per vm rather than per vcpu. Remove the flag, and replace it with checks for the features instead. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-16-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Fix the value of the CPTR_EL2 RES1 bitmask for nVHEFuad Tabba
Since the introduction of SME, bit 12 in CPTR_EL2 (nVHE) is TSM for trapping SME, instead of RES1, as per ARM ARM DDI 0487K.a, section D23.2.34. Fix the value of CPTR_NVHE_EL2_RES1 to reflect that, and adjust the code that relies on it accordingly. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-15-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-20KVM: arm64: Refactor kvm_reset_cptr_el2()Fuad Tabba
Fold kvm_get_reset_cptr_el2() into kvm_reset_cptr_el2(), since it is its only caller. Add a comment to clarify that this function is meant for the host value of cptr_el2. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241216105057.579031-14-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-12-19arm64/sysreg: Get rid of CPACR_ELx SysregFieldsMarc Zyngier
There is no such thing as CPACR_ELx in the architecture. What we have is CPACR_EL1, for which CPTR_EL12 is an accessor. Rename CPACR_ELx_* to CPACR_EL1_*, and fix the bit of code using these names. Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20241219173351.1123087-5-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2024-11-11Merge branch kvm-arm64/nv-pmu into kvmarm/nextOliver Upton
* kvm-arm64/nv-pmu: : Support for vEL2 PMU controls : : Align the vEL2 PMU support with the current state of non-nested KVM, : including: : : - Trap routing, with the annoying complication of EL2 traps that apply : in Host EL0 : : - PMU emulation, using the correct configuration bits depending on : whether a counter falls in the hypervisor or guest range of PMCs : : - Perf event swizzling across nested boundaries, as the event filtering : needs to be remapped to cope with vEL2 KVM: arm64: nv: Reprogram PMU events affected by nested transition KVM: arm64: nv: Apply EL2 event filtering when in hyp context KVM: arm64: nv: Honor MDCR_EL2.HLP KVM: arm64: nv: Honor MDCR_EL2.HPME KVM: arm64: Add helpers to determine if PMC counts at a given EL KVM: arm64: nv: Adjust range of accessible PMCs according to HPMN KVM: arm64: Rename kvm_pmu_valid_counter_mask() KVM: arm64: nv: Advertise support for FEAT_HPMN0 KVM: arm64: nv: Describe trap behaviour of MDCR_EL2.HPMN KVM: arm64: nv: Honor MDCR_EL2.{TPM, TPMCR} in Host EL0 KVM: arm64: nv: Reinject traps that take effect in Host EL0 KVM: arm64: nv: Rename BEHAVE_FORWARD_ANY KVM: arm64: nv: Allow coarse-grained trap combos to use complex traps KVM: arm64: Describe RES0/RES1 bits of MDCR_EL2 arm64: sysreg: Add new definitions for ID_AA64DFR0_EL1 arm64: sysreg: Migrate MDCR_EL2 definition to table arm64: sysreg: Describe ID_AA64DFR2_EL1 fields Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31KVM: arm64: nv: Reinject traps that take effect in Host EL0Oliver Upton
Wire up the other end of traps that affect host EL0 by actually injecting them into the guest hypervisor. Skip over FGT entirely, as a cursory glance suggests no FGT is effective in host EL0. Note that kvm_inject_nested() is already equipped for handling exceptions while the VM is already in a host context. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20241025182354.3364124-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31KVM: arm64: Refactor kvm_vcpu_enable_ptrauth() for hyp useFuad Tabba
Move kvm_vcpu_enable_ptrauth() to a shared header to be used by hypervisor code in protected mode. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20241018074833.2563674-3-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-07-14Merge branch kvm-arm64/nv-sve into kvmarm/nextOliver Upton
* kvm-arm64/nv-sve: : CPTR_EL2, FPSIMD/SVE support for nested : : This series brings support for honoring the guest hypervisor's CPTR_EL2 : trap configuration when running a nested guest, along with support for : FPSIMD/SVE usage at L1 and L2. KVM: arm64: Allow the use of SVE+NV KVM: arm64: nv: Add additional trap setup for CPTR_EL2 KVM: arm64: nv: Add trap description for CPTR_EL2 KVM: arm64: nv: Add TCPAC/TTA to CPTR->CPACR conversion helper KVM: arm64: nv: Honor guest hypervisor's FP/SVE traps in CPTR_EL2 KVM: arm64: nv: Load guest FP state for ZCR_EL2 trap KVM: arm64: nv: Handle CPACR_EL1 traps KVM: arm64: Spin off helper for programming CPTR traps KVM: arm64: nv: Ensure correct VL is loaded before saving SVE state KVM: arm64: nv: Use guest hypervisor's max VL when running nested guest KVM: arm64: nv: Save guest's ZCR_EL2 when in hyp context KVM: arm64: nv: Load guest hyp's ZCR into EL1 state KVM: arm64: nv: Handle ZCR_EL2 traps KVM: arm64: nv: Forward SVE traps to guest hypervisor KVM: arm64: nv: Forward FP/ASIMD traps to guest hypervisor Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-07-14Merge branch kvm-arm64/ctr-el0 into kvmarm/nextOliver Upton
* kvm-arm64/ctr-el0: : Support for user changes to CTR_EL0, courtesy of Sebastian Ott : : Allow userspace to change the guest-visible value of CTR_EL0 for a VM, : so long as the requested value represents a subset of features supported : by hardware. In other words, prevent the VMM from over-promising the : capabilities of hardware. : : Make this happen by fitting CTR_EL0 into the existing infrastructure for : feature ID registers. KVM: selftests: Assert that MPIDR_EL1 is unchanged across vCPU reset KVM: arm64: nv: Unfudge ID_AA64PFR0_EL1 masking KVM: selftests: arm64: Test writes to CTR_EL0 KVM: arm64: rename functions for invariant sys regs KVM: arm64: show writable masks for feature registers KVM: arm64: Treat CTR_EL0 as a VM feature ID register KVM: arm64: unify code to prepare traps KVM: arm64: nv: Use accessors for modifying ID registers KVM: arm64: Add helper for writing ID regs KVM: arm64: Use read-only helper for reading VM ID registers KVM: arm64: Make idregs debugfs iterator search sysreg table directly KVM: arm64: Get sys_reg encoding from descriptor in idregs_debug_show() Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-20KVM: arm64: nv: Handle ZCR_EL2 trapsOliver Upton
Unlike other SVE-related registers, ZCR_EL2 takes a sysreg trap to EL2 when HCR_EL2.NV = 1. KVM still needs to honor the guest hypervisor's trap configuration, which expects an SVE trap (i.e. ESR_EL2.EC = 0x19) when CPTR traps are enabled for the vCPU's current context. Otherwise, if the guest hypervisor has traps disabled, emulate the access by mapping the requested VL into ZCR_EL1. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240620164653.1130714-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-20KVM: arm64: nv: Forward SVE traps to guest hypervisorOliver Upton
Similar to FPSIMD traps, don't load SVE state if the guest hypervisor has SVE traps enabled and forward the trap instead. Note that ZCR_EL2 will require some special handling, as it takes a sysreg trap to EL2 when HCR_EL2.NV = 1. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240620164653.1130714-3-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-20KVM: arm64: nv: Forward FP/ASIMD traps to guest hypervisorJintack Lim
Give precedence to the guest hypervisor's trap configuration when routing an FP/ASIMD trap taken to EL2. Take advantage of the infrastructure for translating CPTR_EL2 into the VHE (i.e. EL1) format and base the trap decision solely on the VHE view of the register. The in-memory value of CPTR_EL2 will always be up to date for the guest hypervisor (more on that later), so just read it directly from memory. Bury all of this behind a macro keyed off of the CPTR bitfield in anticipation of supporting other traps (e.g. SVE). [maz: account for HCR_EL2.E2H when testing for TFP/FPEN, with all the hard work actually being done by Chase Conklin] [ oliver: translate nVHE->VHE format for testing traps; macro for reuse in other CPTR_EL2.xEN fields ] Signed-off-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240620164653.1130714-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-20KVM: arm64: unify code to prepare trapsSebastian Ott
There are 2 functions to calculate traps via HCR_EL2: * kvm_init_sysreg() called via KVM_RUN (before the 1st run or when the pid changes) * vcpu_reset_hcr() called via KVM_ARM_VCPU_INIT To unify these 2 and to support traps that are dependent on the ID register configuration, move the code from vcpu_reset_hcr() to sys_regs.c and call it via kvm_init_sysreg(). We still have to keep the non-FWB handling stuff in vcpu_reset_hcr(). Also the initialization with HCR_GUEST_FLAGS is kept there but guarded by !vcpu_has_run_once() to ensure that previous calculated values don't get overwritten. While at it rename kvm_init_sysreg() to kvm_calculate_traps() to better reflect what it's doing. Signed-off-by: Sebastian Ott <sebott@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20240619174036.483943-7-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-04KVM: arm64: Refactor CPACR trap bit setting/clearing to use ELx formatFuad Tabba
When setting/clearing CPACR bits for EL0 and EL1, use the ELx format of the bits, which covers both. This makes the code clearer, and reduces the chances of accidentally missing a bit. No functional change intended. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-9-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-04KVM: arm64: Abstract set/clear of CPTR_EL2 bits behind helperFuad Tabba
The same traps controlled by CPTR_EL2 or CPACR_EL1 need to be toggled in different parts of the code, but the exact bits and their polarity differ between these two formats and the mode (vhe/nvhe/hvhe). To reduce the amount of duplicated code and the chance of getting the wrong bit/polarity or missing a field, abstract the set/clear of CPTR_EL2 bits behind a helper. Since (h)VHE is the way of the future, use the CPACR_EL1 format, which is a subset of the VHE CPTR_EL2, as a reference. No functional change intended. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20240603122852.3923848-4-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/pkvm-6.10 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/pkvm-6.10: (25 commits) : . : At last, a bunch of pKVM patches, courtesy of Fuad Tabba. : From the cover letter: : : "This series is a bit of a bombay-mix of patches we've been : carrying. There's no one overarching theme, but they do improve : the code by fixing existing bugs in pKVM, refactoring code to : make it more readable and easier to re-use for pKVM, or adding : functionality to the existing pKVM code upstream." : . KVM: arm64: Force injection of a data abort on NISV MMIO exit KVM: arm64: Restrict supported capabilities for protected VMs KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap() KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst KVM: arm64: Rename firmware pseudo-register documentation file KVM: arm64: Reformat/beautify PTP hypercall documentation KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit KVM: arm64: Introduce and use predicates that check for protected VMs KVM: arm64: Add is_pkvm_initialized() helper KVM: arm64: Simplify vgic-v3 hypercalls KVM: arm64: Move setting the page as dirty out of the critical section KVM: arm64: Change kvm_handle_mmio_return() return polarity KVM: arm64: Fix comment for __pkvm_vcpu_init_traps() KVM: arm64: Prevent kmemleak from accessing .hyp.data KVM: arm64: Do not map the host fpsimd state to hyp in pKVM KVM: arm64: Rename __tlb_switch_to_{guest,host}() in VHE KVM: arm64: Support TLB invalidation in guest context KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE KVM: arm64: Check for PTE validity when checking for executable/cacheable KVM: arm64: Avoid BUG-ing from the host abort path ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-03Merge branch kvm-arm64/nv-eret-pauth into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-eret-pauth: : . : Add NV support for the ERETAA/ERETAB instructions. From the cover letter: : : "Although the current upstream NV support has *some* support for : correctly emulating ERET, that support is only partial as it doesn't : support the ERETAA and ERETAB variants. : : Supporting these instructions was cast aside for a long time as it : involves implementing some form of PAuth emulation, something I wasn't : overly keen on. But I have reached a point where enough of the : infrastructure is there that it actually makes sense. So here it is!" : . KVM: arm64: nv: Work around lack of pauth support in old toolchains KVM: arm64: Drop trapping of PAuth instructions/keys KVM: arm64: nv: Advertise support for PAuth KVM: arm64: nv: Handle ERETA[AB] instructions KVM: arm64: nv: Add emulation for ERETAx instructions KVM: arm64: nv: Add kvm_has_pauth() helper KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0 KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently KVM: arm64: nv: Honor HFGITR_EL2.ERET being set KVM: arm64: nv: Fast-track 'InHost' exception returns KVM: arm64: nv: Add trap forwarding for ERET and SMC KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2 KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag KVM: arm64: Constraint PAuth support to consistent implementations KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET* KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-01KVM: arm64: Refactor checks for FP state ownershipFuad Tabba
To avoid direct comparison against the fp_owner enum, add a new function that performs the check, host_owns_fp_regs(), to complement the existing guest_owns_fp_regs(). To check for fpsimd state ownership, use the helpers instead of directly using the enums. No functional change intended. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-4-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: Drop trapping of PAuth instructions/keysMarc Zyngier
We currently insist on disabling PAuth on vcpu_load(), and get to enable it on first guest use of an instruction or a key (ignoring the NV case for now). It isn't clear at all what this is trying to achieve: guests tend to use PAuth when available, and nothing forces you to expose it to the guest if you don't want to. This also isn't totally free: we take a full GPR save/restore between host and guest, only to write ten 64bit registers. The "value proposition" escapes me. So let's forget this stuff and enable PAuth eagerly if exposed to the guest. This results in much simpler code. Performance wise, that's not bad either (tested on M2 Pro running a fully automated Debian installer as the workload): - On a non-NV guest, I can see reduction of 0.24% in the number of cycles (measured with perf over 10 consecutive runs) - On a NV guest (L2), I see a 2% reduction in wall-clock time (measured with 'time', as M2 doesn't have a PMUv3 and NV doesn't support it either) So overall, a much reduced complexity and a (small) performance improvement. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-16-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20KVM: arm64: nv: Handle HCR_EL2.{API,APK} independentlyMarc Zyngier
Although KVM couples API and APK for simplicity, the architecture makes no such requirement, and the two can be independently set or cleared. Check for which of the two possible reasons we have trapped here, and if the corresponding L1 control bit isn't set, delegate the handling for forwarding. Otherwise, set this exact bit in HCR_EL2 and resume the guest. Of course, in the non-NV case, we keep setting both bits and be done with it. Note that the entry core already saves/restores the keys should any of the two control bits be set. This results in a bit of rework, and the removal of the (trivial) vcpu_ptrauth_enable() helper. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240419102935.1935571-10-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-12KVM: arm64: Exclude FP ownership from kvm_vcpu_archMarc Zyngier
In retrospect, it is fairly obvious that the FP state ownership is only meaningful for a given CPU, and that locating this information in the vcpu was just a mistake. Move the ownership tracking into the host data structure, and rename it from fp_state to fp_owner, which is a better description (name suggested by Mark Brown). Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-03-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "S390: - Changes to FPU handling came in via the main s390 pull request - Only deliver to the guest the SCLP events that userspace has requested - More virtual vs physical address fixes (only a cleanup since virtual and physical address spaces are currently the same) - Fix selftests undefined behavior x86: - Fix a restriction that the guest can't program a PMU event whose encoding matches an architectural event that isn't included in the guest CPUID. The enumeration of an architectural event only says that if a CPU supports an architectural event, then the event can be programmed *using the architectural encoding*. The enumeration does NOT say anything about the encoding when the CPU doesn't report support the event *in general*. It might support it, and it might support it using the same encoding that made it into the architectural PMU spec - Fix a variety of bugs in KVM's emulation of RDPMC (more details on individual commits) and add a selftest to verify KVM correctly emulates RDMPC, counter availability, and a variety of other PMC-related behaviors that depend on guest CPUID and therefore are easier to validate with selftests than with custom guests (aka kvm-unit-tests) - Zero out PMU state on AMD if the virtual PMU is disabled, it does not cause any bug but it wastes time in various cases where KVM would check if a PMC event needs to be synthesized - Optimize triggering of emulated events, with a nice ~10% performance improvement in VM-Exit microbenchmarks when a vPMU is exposed to the guest - Tighten the check for "PMI in guest" to reduce false positives if an NMI arrives in the host while KVM is handling an IRQ VM-Exit - Fix a bug where KVM would report stale/bogus exit qualification information when exiting to userspace with an internal error exit code - Add a VMX flag in /proc/cpuinfo to report 5-level EPT support - Rework TDP MMU root unload, free, and alloc to run with mmu_lock held for read, e.g. to avoid serializing vCPUs when userspace deletes a memslot - Tear down TDP MMU page tables at 4KiB granularity (used to be 1GiB). KVM doesn't support yielding in the middle of processing a zap, and 1GiB granularity resulted in multi-millisecond lags that are quite impolite for CONFIG_PREEMPT kernels - Allocate write-tracking metadata on-demand to avoid the memory overhead when a kernel is built with i915 virtualization support but the workloads use neither shadow paging nor i915 virtualization - Explicitly initialize a variety of on-stack variables in the emulator that triggered KMSAN false positives - Fix the debugregs ABI for 32-bit KVM - Rework the "force immediate exit" code so that vendor code ultimately decides how and when to force the exit, which allowed some optimization for both Intel and AMD - Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if vCPU creation ultimately failed, causing extra unnecessary work - Cleanup the logic for checking if the currently loaded vCPU is in-kernel - Harden against underflowing the active mmu_notifier invalidation count, so that "bad" invalidations (usually due to bugs elsehwere in the kernel) are detected earlier and are less likely to hang the kernel x86 Xen emulation: - Overlay pages can now be cached based on host virtual address, instead of guest physical addresses. This removes the need to reconfigure and invalidate the cache if the guest changes the gpa but the underlying host virtual address remains the same - When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation - Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior) - Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs RISC-V: - Support exception and interrupt handling in selftests - New self test for RISC-V architectural timer (Sstc extension) - New extension support (Ztso, Zacas) - Support userspace emulation of random number seed CSRs ARM: - Infrastructure for building KVM's trap configuration based on the architectural features (or lack thereof) advertised in the VM's ID registers - Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to x86's WC) at stage-2, improving the performance of interacting with assigned devices that can tolerate it - Conversion of KVM's representation of LPIs to an xarray, utilized to address serialization some of the serialization on the LPI injection path - Support for _architectural_ VHE-only systems, advertised through the absence of FEAT_E2H0 in the CPU's ID register - Miscellaneous cleanups, fixes, and spelling corrections to KVM and selftests LoongArch: - Set reserved bits as zero in CPUCFG - Start SW timer only when vcpu is blocking - Do not restart SW timer when it is expired - Remove unnecessary CSR register saving during enter guest - Misc cleanups and fixes as usual Generic: - Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically always true on all architectures except MIPS (where Kconfig determines the available depending on CPU capabilities). It is replaced either by an architecture-dependent symbol for MIPS, and IS_ENABLED(CONFIG_KVM) everywhere else - Factor common "select" statements in common code instead of requiring each architecture to specify it - Remove thoroughly obsolete APIs from the uapi headers - Move architecture-dependent stuff to uapi/asm/kvm.h - Always flush the async page fault workqueue when a work item is being removed, especially during vCPU destruction, to ensure that there are no workers running in KVM code when all references to KVM-the-module are gone, i.e. to prevent a very unlikely use-after-free if kvm.ko is unloaded - Grab a reference to the VM's mm_struct in the async #PF worker itself instead of gifting the worker a reference, so that there's no need to remember to *conditionally* clean up after the worker Selftests: - Reduce boilerplate especially when utilize selftest TAP infrastructure - Add basic smoke tests for SEV and SEV-ES, along with a pile of library support for handling private/encrypted/protected memory - Fix benign bugs where tests neglect to close() guest_memfd files" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits) selftests: kvm: remove meaningless assignments in Makefiles KVM: riscv: selftests: Add Zacas extension to get-reg-list test RISC-V: KVM: Allow Zacas extension for Guest/VM KVM: riscv: selftests: Add Ztso extension to get-reg-list test RISC-V: KVM: Allow Ztso extension for Guest/VM RISC-V: KVM: Forward SEED CSR access to user space KVM: riscv: selftests: Add sstc timer test KVM: riscv: selftests: Change vcpu_has_ext to a common function KVM: riscv: selftests: Add guest helper to get vcpu id KVM: riscv: selftests: Add exception handling support LoongArch: KVM: Remove unnecessary CSR register saving during enter guest LoongArch: KVM: Do not restart SW timer when it is expired LoongArch: KVM: Start SW timer only when vcpu is blocking LoongArch: KVM: Set reserved bits as zero in CPUCFG KVM: selftests: Explicitly close guest_memfd files in some gmem tests KVM: x86/xen: fix recursive deadlock in timer injection KVM: pfncache: simplify locking and make more self-contained KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled KVM: x86/xen: improve accuracy of Xen timers ...
2024-02-16arm64: Add ESR decoding for exceptions involving translation level -1Ard Biesheuvel
The LPA2 feature introduces new FSC values to report abort exceptions related to translation level -1. Define these and wire them up. Reuse the new ESR FSC classification helpers that arrived via the KVM arm64 tree, and update the one for translation faults to check specifically for a translation fault at level -1. (Access flag or permission faults cannot occur at level -1 because they alway involve a descriptor at the superior level so changing those helpers is not needed). Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-73-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-08KVM: arm64: Force guest's HCR_EL2.E2H RES1 when NV1 is not implementedMarc Zyngier
If NV1 isn't supported on a system, make sure we always evaluate the guest's HCR_EL2.E2H as RES1, irrespective of what the guest may have written there. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240122181344.258974-10-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-12-19Merge branch kvm-arm64/nv-6.8-prefix into kvmarm-master/nextMarc Zyngier
* kvm-arm64/nv-6.8-prefix: : . : Nested Virtualization support update, focussing on the : NV2 support (VNCR mapping and such). : . KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() KVM: arm64: nv: Map VNCR-capable registers to a separate page KVM: arm64: nv: Add EL2_REG_VNCR()/EL2_REG_REDIR() sysreg helpers KVM: arm64: Introduce a bad_trap() primitive for unexpected trap handling KVM: arm64: nv: Add include containing the VNCR_EL2 offsets KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers KVM: arm64: nv: Drop EL12 register traps that are redirected to VNCR KVM: arm64: nv: Compute NV view of idregs as a one-off KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt() arm64: cpufeatures: Restrict NV support to FEAT_NV2 Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()Marc Zyngier
A rather common idiom when writing NV code as part of KVM is to have things such has: if (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) { [...] } to check that we are in a hyp-related context. The second part of the conjunction would be enough, but the first one contains a static key that allows the rest of the checkis to be elided when in a non-NV environment. Rewrite is_hyp_ctxt() to directly use vcpu_has_nv(). The result is the same, and the code easier to read. The one occurence of this that is already merged is rewritten in the process. In order to avoid nasty cirtular dependencies between kvm_emulate.h and kvm_nested.h, vcpu_has_feature() is itself hoisted into kvm_host.h, at the cost of some #deferry... Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-11-30KVM: arm64: Use helpers to classify exception types reported via ESRArd Biesheuvel
Currently, we rely on the fact that exceptions can be trivially classified by applying a mask/value pair to the syndrome value reported via the ESR register, but this will no longer be true once we enable support for 5 level paging. So introduce a couple of helpers that encapsulate this mask/value pair matching, and wire them up in the code. No functional change intended, the actual handling of translation level -1 will be added in a subsequent patch. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> [maz: folded in changes suggested by Mark] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231128140400.3132145-2-ardb@google.com
2023-11-27KVM: arm64: Support up to 5 levels of translation in kvm_pgtableRyan Roberts
FEAT_LPA2 increases the maximum levels of translation from 4 to 5 for the 4KB page case, when IA is >48 bits. While we can still use 4 levels for stage2 translation in this case (due to stage2 allowing concatenated page tables for first level lookup), the same kvm_pgtable library is used for the hyp stage1 page tables and stage1 does not support concatenation. Therefore, modify the library to support up to 5 levels. Previous patches already laid the groundwork for this by refactoring code to work in terms of KVM_PGTABLE_FIRST_LEVEL and KVM_PGTABLE_LAST_LEVEL. So we just need to change these macros. The hardware sometimes encodes the new level differently from the others: One such place is when reading the level from the FSC field in the ESR_EL2 register. We never expect to see the lowest level (-1) here since the stage 2 page tables always use concatenated tables for first level lookup and therefore only use 4 levels of lookup. So we get away with just adding a comment to explain why we are not being careful about decoding level -1. For stage2 VTCR_EL2.SL2 is introduced to encode the new start level. However, since we always use concatenated page tables for first level look up at stage2 (and therefore we will never need the new extra level) we never touch this new field. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231127111737.1897081-10-ryan.roberts@arm.com
2023-11-27KVM: arm64: Convert translation level parameter to s8Ryan Roberts
With the introduction of FEAT_LPA2, the Arm ARM adds a new level of translation, level -1, so levels can now be in the range [-1;3]. 3 is always the last level and the first level is determined based on the number of VA bits in use. Convert level variables to use a signed type in preparation for supporting this new level -1. Since the last level is always anchored at 3, and the first level varies to suit the number of VA/IPA bits, take the opportunity to replace KVM_PGTABLE_MAX_LEVELS with the 2 macros KVM_PGTABLE_FIRST_LEVEL and KVM_PGTABLE_LAST_LEVEL. This removes the assumption from the code that levels run from 0 to KVM_PGTABLE_MAX_LEVELS - 1, which will soon no longer be true. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231127111737.1897081-9-ryan.roberts@arm.com
2023-11-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Generalized infrastructure for 'writable' ID registers, effectively allowing userspace to opt-out of certain vCPU features for its guest - Optimization for vSGI injection, opportunistically compressing MPIDR to vCPU mapping into a table - Improvements to KVM's PMU emulation, allowing userspace to select the number of PMCs available to a VM - Guest support for memory operation instructions (FEAT_MOPS) - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing bugs and getting rid of useless code - Changes to the way the SMCCC filter is constructed, avoiding wasted memory allocations when not in use - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing the overhead of errata mitigations - Miscellaneous kernel and selftest fixes LoongArch: - New architecture for kvm. The hardware uses the same model as x86, s390 and RISC-V, where guest/host mode is orthogonal to supervisor/user mode. The virtualization extensions are very similar to MIPS, therefore the code also has some similarities but it's been cleaned up to avoid some of the historical bogosities that are found in arch/mips. The kernel emulates MMU, timer and CSR accesses, while interrupt controllers are only emulated in userspace, at least for now. RISC-V: - Support for the Smstateen and Zicond extensions - Support for virtualizing senvcfg - Support for virtualized SBI debug console (DBCN) S390: - Nested page table management can be monitored through tracepoints and statistics x86: - Fix incorrect handling of VMX posted interrupt descriptor in KVM_SET_LAPIC, which could result in a dropped timer IRQ - Avoid WARN on systems with Intel IPI virtualization - Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs without forcing more common use cases to eat the extra memory overhead. - Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and SBPB, aka Selective Branch Predictor Barrier). - Fix a bug where restoring a vCPU snapshot that was taken within 1 second of creating the original vCPU would cause KVM to try to synchronize the vCPU's TSC and thus clobber the correct TSC being set by userspace. - Compute guest wall clock using a single TSC read to avoid generating an inaccurate time, e.g. if the vCPU is preempted between multiple TSC reads. - "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which complain about a "Firmware Bug" if the bit isn't set for select F/M/S combos. Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to appease Windows Server 2022. - Don't apply side effects to Hyper-V's synthetic timer on writes from userspace to fix an issue where the auto-enable behavior can trigger spurious interrupts, i.e. do auto-enabling only for guest writes. - Remove an unnecessary kick of all vCPUs when synchronizing the dirty log without PML enabled. - Advertise "support" for non-serializing FS/GS base MSR writes as appropriate. - Harden the fast page fault path to guard against encountering an invalid root when walking SPTEs. - Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n. - Use the fast path directly from the timer callback when delivering Xen timer events, instead of waiting for the next iteration of the run loop. This was not done so far because previously proposed code had races, but now care is taken to stop the hrtimer at critical points such as restarting the timer or saving the timer information for userspace. - Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future flag. - Optimize injection of PMU interrupts that are simultaneous with NMIs. - Usual handful of fixes for typos and other warts. x86 - MTRR/PAT fixes and optimizations: - Clean up code that deals with honoring guest MTRRs when the VM has non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled. - Zap EPT entries when non-coherent DMA assignment stops/start to prevent using stale entries with the wrong memtype. - Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y This was done as a workaround for virtual machine BIOSes that did not bother to clear CR0.CD (because ancient KVM/QEMU did not bother to set it, in turn), and there's zero reason to extend the quirk to also ignore guest PAT. x86 - SEV fixes: - Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts SHUTDOWN while running an SEV-ES guest. - Clean up the recognition of emulation failures on SEV guests, when KVM would like to "skip" the instruction but it had already been partially emulated. This makes it possible to drop a hack that second guessed the (insufficient) information provided by the emulator, and just do the right thing. Documentation: - Various updates and fixes, mostly for x86 - MTRR and PAT fixes and optimizations" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (164 commits) KVM: selftests: Avoid using forced target for generating arm64 headers tools headers arm64: Fix references to top srcdir in Makefile KVM: arm64: Add tracepoint for MMIO accesses where ISV==0 KVM: arm64: selftest: Perform ISB before reading PAR_EL1 KVM: arm64: selftest: Add the missing .guest_prepare() KVM: arm64: Always invalidate TLB for stage-2 permission faults KVM: x86: Service NMI requests after PMI requests in VM-Enter path KVM: arm64: Handle AArch32 SPSR_{irq,abt,und,fiq} as RAZ/WI KVM: arm64: Do not let a L1 hypervisor access the *32_EL2 sysregs KVM: arm64: Refine _EL2 system register list that require trap reinjection arm64: Add missing _EL2 encodings arm64: Add missing _EL12 encodings KVM: selftests: aarch64: vPMU test for validating user accesses KVM: selftests: aarch64: vPMU register test for unimplemented counters KVM: selftests: aarch64: vPMU register test for implemented counters KVM: selftests: aarch64: Introduce vpmu_counter_access test tools: Import arm_pmuv3.h KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} ...
2023-10-30Merge branch kvm-arm64/sgi-injection into kvmarm/nextOliver Upton
* kvm-arm64/sgi-injection: : vSGI injection improvements + fixes, courtesy Marc Zyngier : : Avoid linearly searching for vSGI targets using a compressed MPIDR to : index a cache. While at it, fix some egregious bugs in KVM's mishandling : of vcpuid (user-controlled value) and vcpu_idx. KVM: arm64: Clarify the ordering requirements for vcpu/RD creation KVM: arm64: vgic-v3: Optimize affinity-based SGI injection KVM: arm64: Fast-track kvm_mpidr_to_vcpu() when mpidr_data is available KVM: arm64: Build MPIDR to vcpu index cache at runtime KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff() KVM: arm64: Use vcpu_idx for invalidation tracking KVM: arm64: vgic: Use vcpu_idx for the debug information KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_id KVM: arm64: vgic-v3: Refactor GICv3 SGI generation KVM: arm64: vgic-its: Treat the collection target address as a vcpu_id KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointer Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-16arm64: kvm: Use cpus_have_final_cap() explicitlyMark Rutland
Much of the arm64 KVM code uses cpus_have_const_cap() to check for cpucaps, but this is unnecessary and it would be preferable to use cpus_have_final_cap(). For historical reasons, cpus_have_const_cap() is more complicated than it needs to be. Before cpucaps are finalized, it will perform a bitmap test of the system_cpucaps bitmap, and once cpucaps are finalized it will use an alternative branch. This used to be necessary to handle some race conditions in the window between cpucap detection and the subsequent patching of alternatives and static branches, where different branches could be out-of-sync with one another (or w.r.t. alternative sequences). Now that we use alternative branches instead of static branches, these are all patched atomically w.r.t. one another, and there are only a handful of cases that need special care in the window between cpucap detection and alternative patching. Due to the above, it would be nice to remove cpus_have_const_cap(), and migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(), or cpus_have_cap() depending on when their requirements. This will remove redundant instructions and improve code generation, and will make it easier to determine how each callsite will behave before, during, and after alternative patching. KVM is initialized after cpucaps have been finalized and alternatives have been patched. Since commit: d86de40decaa14e6 ("arm64: cpufeature: upgrade hyp caps to final") ... use of cpus_have_const_cap() in hyp code is automatically converted to use cpus_have_final_cap(): | static __always_inline bool cpus_have_const_cap(int num) | { | if (is_hyp_code()) | return cpus_have_final_cap(num); | else if (system_capabilities_finalized()) | return __cpus_have_const_cap(num); | else | return cpus_have_cap(num); | } Thus, converting hyp code to use cpus_have_final_cap() directly will not result in any functional change. Non-hyp KVM code is also not executed until cpucaps have been finalized, and it would be preferable to extent the same treatment to this code and use cpus_have_final_cap() directly. This patch converts instances of cpus_have_const_cap() in KVM-only code over to cpus_have_final_cap(). As all of this code runs after cpucaps have been finalized, there should be no functional change as a result of this patch, but the redundant instructions generated by cpus_have_const_cap() will be removed from the non-hyp KVM code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-09-30KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff()Marc Zyngier
By definition, MPIDR_EL1 cannot be modified by the guest. This means it is pointless to check whether this is loaded on the CPU. Simplify the kvm_vcpu_get_mpidr_aff() helper to directly access the in-memory value. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Joey Gouly <joey.gouly@arm.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-8-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Get rid of vCPU-scoped feature bitmapOliver Upton
The vCPU-scoped feature bitmap was left in place a couple of releases ago in case the change to VM-scoped vCPU features broke anyone. Nobody has complained and the interop between VM and vCPU bitmaps is pretty gross. Throw it out. Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-07-26KVM: arm64: Fix resetting SME trap values on reset for (h)VHEFuad Tabba
Ensure that SME traps are disabled for (h)VHE when getting the reset value for the architectural feature control register. Fixes: 75c76ab5a641 ("KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration") Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230724123829.2929609-9-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-07-26KVM: arm64: Fix resetting SVE trap values on reset for hVHEFuad Tabba
Ensure that SVE traps are disabled for hVHE, if the FPSIMD state isn't owned by the guest, when getting the reset value for the architectural feature control register. Fixes: 75c76ab5a641 ("KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration") Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230724123829.2929609-8-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-07-26KVM: arm64: Helper to write to appropriate feature trap register based on modeFuad Tabba
Factor out the code that decides whether to write to the feature trap registers, CPTR_EL2 or CPACR_EL1, based on the KVM mode, i.e., (h)VHE or nVHE. This function will be used in the subsequent patch. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230724123829.2929609-6-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15Merge branch kvm-arm64/misc into kvmarm/nextOliver Upton
* kvm-arm64/misc: : Miscellaneous updates : : - Avoid trapping CTR_EL0 on systems with FEAT_EVT, as the register is : commonly read by userspace : : - Make use of FEAT_BTI at hyp stage-1, setting the Guard Page bit to 1 : for executable mappings : : - Use a separate set of pointer authentication keys for the hypervisor : when running in protected mode (i.e. pKVM) : : - Plug a few holes in timer initialization where KVM fails to free the : timer IRQ(s) KVM: arm64: Use different pointer authentication keys for pKVM KVM: arm64: timers: Fix resource leaks in kvm_timer_hyp_init() KVM: arm64: Use BTI for nvhe KVM: arm64: Relax trapping of CTR_EL0 when FEAT_EVT is available Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15Merge branch kvm-arm64/configurable-id-regs into kvmarm/nextOliver Upton
* kvm-arm64/configurable-id-regs: : Configurable ID register infrastructure, courtesy of Jing Zhang : : Create generalized infrastructure for allowing userspace to select the : supported feature set for a VM, so long as the feature set is a subset : of what hardware + KVM allows. This does not add any new features that : are user-configurable, and instead focuses on the necessary refactoring : to enable future work. : : As a consequence of the series, feature asymmetry is now deliberately : disallowed for KVM. It is unlikely that VMMs ever configured VMs with : asymmetry, nor does it align with the kernel's overall stance that : features must be uniform across all cores in the system. : : Furthermore, KVM incorrectly advertised an IMP_DEF PMU to guests for : some time. Migrations from affected kernels was supported by explicitly : allowing such an ID register value from userspace, and forwarding that : along to the guest. KVM now allows an IMP_DEF PMU version to be restored : through the ID register interface, but reinterprets the user value as : not implemented (0). KVM: arm64: Rip out the vestiges of the 'old' ID register scheme KVM: arm64: Handle ID register reads using the VM-wide values KVM: arm64: Use generic sanitisation for ID_AA64PFR0_EL1 KVM: arm64: Use generic sanitisation for ID_(AA64)DFR0_EL1 KVM: arm64: Use arm64_ftr_bits to sanitise ID register writes KVM: arm64: Save ID registers' sanitized value per guest KVM: arm64: Reuse fields of sys_reg_desc for idreg KVM: arm64: Rewrite IMPDEF PMU version as NI KVM: arm64: Make vCPU feature flags consistent VM-wide KVM: arm64: Relax invariance of KVM_ARM_VCPU_POWER_OFF KVM: arm64: Separate out feature sanitisation and initialisation Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-12KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is setMarc Zyngier
Also make sure HCR_EL2.E2H is set when switching HCR_EL2 in guest context. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230609162200.2024064-16-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>