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2024-02-01KVM: arm64: vhe: fix a kernel-doc warningRandy Dunlap1-1/+1
Use the correct function name in the kernel-doc comment to prevent a warning: arch/arm64/kvm/hyp/vhe/sysreg-sr.c:109: warning: expecting prototype for __vcpu_put_switch_syregs(). Prototype was for __vcpu_put_switch_sysregs() instead Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Zenghui Yu <yuzenghui@huawei.com> Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.linux.dev Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20240117230714.31025-5-rdunlap@infradead.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-12-05KVM: arm64: Remove VPIPT I-cache handlingMarc Zyngier1-13/+0
We have some special handling for VPIPT I-cache in critical parts of the cache and TLB maintenance. Remove it. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20231204143606.1806432-2-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2023-10-31Merge tag 'kvmarm-6.7' of ↵Paolo Bonzini3-24/+39
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.7 - 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
2023-10-30Merge branch kvm-arm64/mops into kvmarm/nextOliver Upton1-0/+1
* kvm-arm64/mops: : KVM support for MOPS, courtesy of Kristina Martsenko : : MOPS adds new instructions for accelerating memcpy(), memset(), and : memmove() operations in hardware. This series brings virtualization : support for KVM guests, and allows VMs to run on asymmetrict systems : that may have different MOPS implementations. KVM: arm64: Expose MOPS instructions to guests KVM: arm64: Add handler for MOPS exceptions Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-20KVM: arm64: Load the stage-2 MMU context in kvm_vcpu_load_vhe()Oliver Upton1-10/+5
To date the VHE code has aggressively reloaded the stage-2 MMU context on every guest entry, despite the fact that this isn't necessary. This was probably done for consistency with the nVHE code, which needs to switch in/out the stage-2 MMU context as both the host and guest run at EL1. Hoist __load_stage2() into kvm_vcpu_load_vhe(), thus avoiding a reload on every guest entry/exit. This is likely to be beneficial to systems with one of the speculative AT errata, as there is now one fewer context synchronization event on the guest entry path. Additionally, it is possible that implementations have hitched correctness mitigations on writes to VTTBR_EL2, which are now elided on guest re-entry. Note that __tlb_switch_to_guest() is deliberately left untouched as it can be called outside the context of a running vCPU. Link: https://lore.kernel.org/r/20231018233212.2888027-6-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-20KVM: arm64: Rename helpers for VHE vCPU load/putOliver Upton2-10/+19
The names for the helpers we expose to the 'generic' KVM code are a bit imprecise; we switch the EL0 + EL1 sysreg context and setup trap controls that do not need to change for every guest entry/exit. Rename + shuffle things around a bit in preparation for loading the stage-2 MMU context on vcpu_load(). Link: https://lore.kernel.org/r/20231018233212.2888027-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-20KVM: arm64: Restore the stage-2 context in VHE's __tlb_switch_to_host()Marc Zyngier1-3/+14
An MMU notifier could cause us to clobber the stage-2 context loaded on a CPU when we switch to another VM's context to invalidate. This isn't an issue right now as the stage-2 context gets reloaded on every guest entry, but is disastrous when moving __load_stage2() into the vcpu_load() path. Restore the previous stage-2 context on the way out of a TLB invalidation if we installed something else. Deliberately do this after TGE=1 is synchronized to keep things safe in light of the speculative AT errata. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231018233212.2888027-3-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-20KVM: arm64: Don't zero VTTBR in __tlb_switch_to_host()Oliver Upton1-1/+0
HCR_EL2.TGE=0 is sufficient to disable stage-2 translation, so there's no need to explicitly zero VTTBR_EL2. Link: https://lore.kernel.org/r/20231018233212.2888027-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-12KVM: arm64: timers: Correctly handle TGE flip with CNTPOFF_EL2Marc Zyngier1-0/+44
Contrary to common belief, HCR_EL2.TGE has a direct and immediate effect on the way the EL0 physical counter is offset. Flipping TGE from 1 to 0 while at EL2 immediately changes the way the counter compared to the CVAL limit. This means that we cannot directly save/restore the guest's view of CVAL, but that we instead must treat it as if CNTPOFF didn't exist. Only in the world switch, once we figure out that we do have CNTPOFF, can we must the offset back and forth depending on the polarity of TGE. Fixes: 2b4825a86940 ("KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer") Reported-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Tested-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-10-09KVM: arm64: Add handler for MOPS exceptionsKristina Martsenko1-0/+1
An Armv8.8 FEAT_MOPS main or epilogue instruction will take an exception if executed on a CPU with a different MOPS implementation option (A or B) than the CPU where the preceding prologue instruction ran. In this case the OS exception handler is expected to reset the registers and restart execution from the prologue instruction. A KVM guest may use the instructions at EL1 at times when the guest is not able to handle the exception, expecting that the instructions will only run on one CPU (e.g. when running UEFI boot services in the guest). As KVM may reschedule the guest between different types of CPUs at any time (on an asymmetric system), it needs to also handle the resulting exception itself in case the guest is not able to. A similar situation will also occur in the future when live migrating a guest from one type of CPU to another. Add handling for the MOPS exception to KVM. The handling can be shared with the EL0 exception handler, as the logic and register layouts are the same. The exception can be handled right after exiting a guest, which avoids the cost of returning to the host exit handler. Similarly to the EL0 exception handler, in case the main or epilogue instruction is being single stepped, it makes sense to finish the step before executing the prologue instruction, so advance the single step state machine. Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230922112508.1774352-2-kristina.martsenko@arm.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-08-17KVM: arm64: Implement __kvm_tlb_flush_vmid_range()Raghavendra Rao Ananta1-0/+28
Define __kvm_tlb_flush_vmid_range() (for VHE and nVHE) to flush a range of stage-2 page-tables using IPA in one go. If the system supports FEAT_TLBIRANGE, the following patches would conveniently replace global TLBI such as vmalls12e1is in the map, unmap, and dirty-logging paths with ripas2e1is instead. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230811045127.3308641-10-rananta@google.com
2023-07-01Merge tag 'kvmarm-6.5' of ↵Paolo Bonzini2-1/+33
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.5 - Eager page splitting optimization for dirty logging, optionally allowing for a VM to avoid the cost of block splitting in the stage-2 fault path. - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with services that live in the Secure world. pKVM intervenes on FF-A calls to guarantee the host doesn't misuse memory donated to the hyp or a pKVM guest. - Support for running the split hypervisor with VHE enabled, known as 'hVHE' mode. This is extremely useful for testing the split hypervisor on VHE-only systems, and paves the way for new use cases that depend on having two TTBRs available at EL2. - Generalized framework for configurable ID registers from userspace. KVM/arm64 currently prevents arbitrary CPU feature set configuration from userspace, but the intent is to relax this limitation and allow userspace to select a feature set consistent with the CPU. - Enable the use of Branch Target Identification (FEAT_BTI) in the hypervisor. - Use a separate set of pointer authentication keys for the hypervisor when running in protected mode, as the host is untrusted at runtime. - Ensure timer IRQs are consistently released in the init failure paths. - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps (FEAT_EVT), as it is a register commonly read from userspace. - Erratum workaround for the upcoming AmpereOne part, which has broken hardware A/D state management. As a consequence of the hVHE series reworking the arm64 software features framework, the for-next/module-alloc branch from the arm64 tree comes along for the ride.
2023-06-15Merge branch kvm-arm64/hvhe into kvmarm/nextOliver Upton1-1/+1
* kvm-arm64/hvhe: : Support for running split-hypervisor w/VHE, courtesy of Marc Zyngier : : From the cover letter: : : KVM (on ARMv8.0) and pKVM (on all revisions of the architecture) use : the split hypervisor model that makes the EL2 code more or less : standalone. In the later case, we totally ignore the VHE mode and : stick with the good old v8.0 EL2 setup. : : We introduce a new "mode" for KVM called hVHE, in reference to the : nVHE mode, and indicating that only the hypervisor is using VHE. KVM: arm64: Fix hVHE init on CPUs where HCR_EL2.E2H is not RES1 arm64: Allow arm64_sw.hvhe on command line KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set KVM: arm64: Program the timer traps with VHE layout in hVHE mode KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration KVM: arm64: Adjust EL2 stage-1 leaf AP bits when ARM64_KVM_HVHE is set KVM: arm64: Disable TTBR1_EL2 when using ARM64_KVM_HVHE KVM: arm64: Force HCR_EL2.E2H when ARM64_KVM_HVHE is set KVM: arm64: Key use of VHE instructions in nVHE code off ARM64_KVM_HVHE KVM: arm64: Remove alternatives from sysreg accessors in VHE hypervisor context arm64: Use CPACR_EL1 format to set CPTR_EL2 when E2H is set arm64: Allow EL1 physical timer access when running VHE arm64: Don't enable VHE for the kernel if OVERRIDE_HVHE is set arm64: Add KVM_HVHE capability and has_hvhe() predicate arm64: Turn kaslr_feature_override into a generic SW feature override arm64: Prevent the use of is_kernel_in_hyp_mode() in hypervisor code KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page() Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-13KVM: arm64: Rework CPTR_EL2 programming for HVHE configurationMarc Zyngier1-1/+1
Just like we repainted the early arm64 code, we need to update the CPTR_EL2 accesses that are taking place in the nVHE code when hVHE is used, making them look as if they were CPACR_EL1 accesses. Just like the VHE code. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230609162200.2024064-14-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-04KVM: arm64: PMU: Don't overwrite PMUSERENR with vcpu loadedReiji Watanabe1-0/+14
Currently, with VHE, KVM sets ER, CR, SW and EN bits of PMUSERENR_EL0 to 1 on vcpu_load(), and saves and restores the register value for the host on vcpu_load() and vcpu_put(). If the value of those bits are cleared on a pCPU with a vCPU loaded (armv8pmu_start() would do that when PMU counters are programmed for the guest), PMU access from the guest EL0 might be trapped to the guest EL1 directly regardless of the current PMUSERENR_EL0 value of the vCPU. Fix this by not letting armv8pmu_start() overwrite PMUSERENR_EL0 on the pCPU where PMUSERENR_EL0 for the guest is loaded, and instead updating the saved shadow register value for the host so that the value can be restored on vcpu_put() later. While vcpu_{put,load}() are manipulating PMUSERENR_EL0, disable IRQs to prevent a race condition between these processes and IPIs that attempt to update PMUSERENR_EL0 for the host EL0. Suggested-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Marc Zyngier <maz@kernel.org> Fixes: 83a7a4d643d3 ("arm64: perf: Enable PMU counter userspace access for perf event") Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230603025035.3781797-3-reijiw@google.com
2023-05-30KVM: arm64: Populate fault info for watchpointAkihiko Odaki1-0/+1
When handling ESR_ELx_EC_WATCHPT_LOW, far_el2 member of struct kvm_vcpu_fault_info will be copied to far member of struct kvm_debug_exit_arch and exposed to the userspace. The userspace will see stale values from older faults if the fault info does not get populated. Fixes: 8fb2046180a0 ("KVM: arm64: Move early handlers to per-EC handlers") Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230530024651.10014-1-akihiko.odaki@daynix.com Cc: stable@vger.kernel.org
2023-05-16KVM: arm64: Use local TLBI on permission relaxationMarc Zyngier1-0/+32
Broadcast TLB invalidations (TLBIs) targeting the Inner Shareable Domain are usually less performant than their non-shareable variant. In particular, we observed some implementations that take millliseconds to complete parallel broadcasted TLBIs. It's safe to use non-shareable TLBIs when relaxing permissions on a PTE in the KVM case. According to the ARM ARM (0487I.a) section D8.13.1 "Using break-before-make when updating translation table entries", permission relaxation does not need break-before-make. Specifically, R_WHZWS states that these are the only changes that require a break-before-make sequence: changes of memory type (Shareability or Cacheability), address changes, or changing the block size. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Link: https://lore.kernel.org/r/20230426172330.1439644-13-ricarkol@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-04-14KVM: arm64: vhe: Drop extra isb() on guest exitMarc Zyngier1-4/+3
__kvm_vcpu_run_vhe() end on VHE with an isb(). However, this function is only reachable via kvm_call_hyp_ret(), which already contains an isb() in order to mimick the behaviour of nVHE and provide a context synchronisation event. We thus have two isb()s back to back, which is one too many. Drop the first one and solely rely on the one in the helper. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
2023-04-14KVM: arm64: vhe: Synchronise with page table walker on MMU updateMarc Zyngier1-0/+12
Contrary to nVHE, VHE is a lot easier when it comes to dealing with speculative page table walks started at EL1. As we only change EL1&0 translation regime when context-switching, we already benefit from the effect of the DSB that sits in the context switch code. We only need to take care of it in the NV case, where we can flip between between two EL1 contexts (one of them being the virtual EL2) without a context switch. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-14Merge branch kvm-arm64/nv-prefix into kvmarm/nextOliver Upton1-0/+24
* kvm-arm64/nv-prefix: : Preamble to NV support, courtesy of Marc Zyngier. : : This brings in a set of prerequisite patches for supporting nested : virtualization in KVM/arm64. Of course, there is a long way to go until : NV is actually enabled in KVM. : : - Introduce cpucap / vCPU feature flag to pivot the NV code on : : - Add support for EL2 vCPU register state : : - Basic nested exception handling : : - Hide unsupported features from the ID registers for NV-capable VMs KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes KVM: arm64: nv: Filter out unsupported features from ID regs KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 KVM: arm64: nv: Allow a sysreg to be hidden from userspace only KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2 KVM: arm64: nv: Handle SMCs taken from virtual EL2 KVM: arm64: nv: Handle trapped ERET from virtual EL2 KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 KVM: arm64: nv: Support virtual EL2 exceptions KVM: arm64: nv: Handle HCR_EL2.NV system register traps KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state KVM: arm64: nv: Add EL2 system registers to vcpu context KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set KVM: arm64: nv: Introduce nested virtualization VCPU feature KVM: arm64: Use the S2 MMU context to iterate over S2 table arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisorMarc Zyngier1-0/+24
We can no longer blindly copy the VCPU's PSTATE into SPSR_EL2 and return to the guest and vice versa when taking an exception to the hypervisor, because we emulate virtual EL2 in EL1 and therefore have to translate the mode field from EL2 to EL1 and vice versa. This requires keeping track of the state we enter the guest, for which we transiently use a dedicated flag. Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230209175820.1939006-15-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-13KVM: arm64: Kill CPACR_EL1_TTA definitionMarc Zyngier1-1/+1
Since the One True Way is to use the new generated definition, kill the KVM-specific definition of CPACR_EL1_TTA, and move over to CPACR_ELx_TTA, hopefully for the same result. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230112154803.1808559-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2022-12-05Merge branch kvm-arm64/misc-6.2 into kvmarm-master/nextMarc Zyngier1-1/+1
* kvm-arm64/misc-6.2: : . : Misc fixes for 6.2: : : - Fix formatting for the pvtime documentation : : - Fix a comment in the VHE-specific Makefile : . KVM: arm64: Fix typo in comment KVM: arm64: Fix pvtime documentation Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-11-11KVM: arm64: Fix typo in commentZhiyuan Dai1-1/+1
Fix typo in comment (nVHE/VHE). Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/1667737840-702-1-git-send-email-daizhiyuan@phytium.com.cn
2022-11-01KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHEMarc Zyngier1-8/+0
The trapping of SMPRI_EL1 and TPIDR2_EL0 currently only really work on nVHE, as only this mode uses the fine-grained trapping that controls these two registers. Move the trapping enable/disable code into __{de,}activate_traps_common(), allowing it to be called when it actually matters on VHE, and remove the flipping of EL2 control for TPIDR2_EL0, which only affects the host access of this register. Fixes: 861262ab8627 ("KVM: arm64: Handle SME host state when running guests") Reported-by: Mark Brown <broonie@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/86bkpqer4z.wl-maz@kernel.org
2022-07-17Merge branch kvm-arm64/misc-5.20 into kvmarm-master/nextMarc Zyngier1-1/+1
* kvm-arm64/misc-5.20: : . : Misc fixes for 5.20: : : - Tidy up the hyp/nvhe Makefile : : - Fix functions pointlessly returning a void value : : - Fix vgic_init selftest to handle the GICv3-on-v3 case : : - Fix hypervisor symbolisation when CONFIG_RANDOMIZE_BASE=y : . KVM: arm64: Fix hypervisor address symbolization KVM: arm64: selftests: Add support for GICv2 on v3 KVM: arm64: Don't return from void function KVM: arm64: nvhe: Add intermediates to 'targets' instead of extra-y KVM: arm64: nvhe: Rename confusing obj-y Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-06KVM: arm64: Don't return from void functionQuentin Perret1-1/+1
Although harmless, the return statement in kvm_unexpected_el2_exception is rather confusing as the function itself has a void return type. The C standard is also pretty clear that "A return statement with an expression shall not appear in a function whose return type is void". Given that this return statement does not seem to add any actual value, let's not pointlessly violate the standard. Build-tested with GCC 10 and CLANG 13 for good measure, the disassembled code is identical with or without the return statement. Fixes: e9ee186bb735 ("KVM: arm64: Add kvm_extable for vaxorcism code") Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220705142310.3847918-1-qperret@google.com
2022-06-29KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flagMarc Zyngier1-2/+2
The aptly named boolean 'sysregs_loaded_on_cpu' tracks whether some of the vcpu system registers are resident on the physical CPU when running in VHE mode. This is obviously a flag in hidding, so let's convert it to a state flag, since this is solely a host concern (the hypervisor itself always knows which state we're in). Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-09KVM: arm64: Move FP state ownership from flag to a tristateMarc Zyngier1-1/+1
The KVM FP code uses a pair of flags to denote three states: - FP_ENABLED set: the guest owns the FP state - FP_HOST set: the host owns the FP state - FP_ENABLED and FP_HOST clear: nobody owns the FP state at all and both flags set is an illegal state, which nothing ever checks for... As it turns out, this isn't really a good match for flags, and we'd be better off if this was a simpler tristate, each state having a name that actually reflect the state: - FP_STATE_FREE - FP_STATE_HOST_OWNED - FP_STATE_GUEST_OWNED Kill the two flags, and move over to an enum encoding these three states. This results in less confusing code, and less risk of ending up in the uncharted territory of a 4th state if we forget to clear one of the two flags. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Reiji Watanabe <reijiw@google.com>
2022-06-09KVM: arm64: Drop FP_FOREIGN_STATE from the hypervisor codeMarc Zyngier1-1/+1
The vcpu KVM_ARM64_FP_FOREIGN_FPSTATE flag tracks the thread's own TIF_FOREIGN_FPSTATE so that we can evaluate just before running the vcpu whether it the FP regs contain something that is owned by the vcpu or not by updating the rest of the FP flags. We do this in the hypervisor code in order to make sure we're in a context where we are not interruptible. But we already have a hook in the run loop to generate this flag. We may as well update the FP flags directly and save the pointless flag tracking. Whilst we're at it, rename update_fp_enabled() to guest_owns_fp_regs() to indicate what the leftover of this helper actually do. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Mark Brown <broonie@kernel.org>
2022-04-22KVM: arm64: Trap SME usage in guestMark Brown1-1/+10
SME defines two new traps which need to be enabled for guests to ensure that they can't use SME, one for the main SME operations which mirrors the traps for SVE and another for access to TPIDR2 in SCTLR_EL2. For VHE manage SMEN along with ZEN in activate_traps() and the FP state management callbacks, along with SCTLR_EL2.EnTPIDR2. There is no existing dynamic management of SCTLR_EL2. For nVHE manage TSM in activate_traps() along with the fine grained traps for TPIDR2 and SMPRI. There is no existing dynamic management of fine grained traps. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220419112247.711548-26-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-03-14Merge branch 'for-next/spectre-bhb' into for-next/coreWill Deacon1-2/+8
Merge in the latest Spectre mess to fix up conflicts with what was already queued for 5.18 when the embargo finally lifted. * for-next/spectre-bhb: (21 commits) arm64: Do not include __READ_ONCE() block in assembly files arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting arm64: Use the clearbhb instruction in mitigations KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated arm64: Mitigate spectre style branch history side channels arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 arm64: Add percpu vectors for EL1 arm64: entry: Add macro for reading symbol addresses from the trampoline arm64: entry: Add vectors that have the bhb mitigation sequences arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations arm64: entry: Allow the trampoline text to occupy multiple pages arm64: entry: Make the kpti trampoline's kpti sequence optional arm64: entry: Move trampoline macros out of ifdef'd section arm64: entry: Don't assume tramp_vectors is the start of the vectors arm64: entry: Allow tramp_alias to access symbols after the 4K boundary arm64: entry: Move the trampoline data page before the text page arm64: entry: Free up another register on kpti's tramp_exit path arm64: entry: Make the trampoline cleanup optional KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit ...
2022-02-25arm64: Always use individual bits in CPACR floating point enablesMark Brown1-3/+3
CPACR_EL1 has several bitfields for controlling traps for floating point features to EL1, each of which has a separate bits for EL0 and EL1. Marc Zyngier noted that we are not consistent in our use of defines to manipulate these, sometimes using a define covering the whole field and sometimes using defines for the individual bits. Make this consistent by expanding the whole field defines where they are used (currently only in the KVM code) and deleting them so that no further uses can be introduced. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20220207152109.197566-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2022-02-16arm64: Add percpu vectors for EL1James Morse1-2/+8
The Spectre-BHB workaround adds a firmware call to the vectors. This is needed on some CPUs, but not others. To avoid the unaffected CPU in a big/little pair from making the firmware call, create per cpu vectors. The per-cpu vectors only apply when returning from EL0. Systems using KPTI can use the canonical 'full-fat' vectors directly at EL1, the trampoline exit code will switch to this_cpu_vector on exit to EL0. Systems not using KPTI should always use this_cpu_vector. this_cpu_vector will point at a vector in tramp_vecs or __bp_harden_el1_vectors, depending on whether KPTI is in use. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2022-01-07Merge tag 'kvmarm-5.17' of ↵Paolo Bonzini1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 5.16 - Simplification of the 'vcpu first run' by integrating it into KVM's 'pid change' flow - Refactoring of the FP and SVE state tracking, also leading to a simpler state and less shared data between EL1 and EL2 in the nVHE case - Tidy up the header file usage for the nvhe hyp object - New HYP unsharing mechanism, finally allowing pages to be unmapped from the Stage-1 EL2 page-tables - Various pKVM cleanups around refcounting and sharing - A couple of vgic fixes for bugs that would trigger once the vcpu xarray rework is merged, but not sooner - Add minimal support for ARMv8.7's PMU extension - Rework kvm_pgtable initialisation ahead of the NV work - New selftest for IRQ injection - Teach selftests about the lack of default IPA space and page sizes - Expand sysreg selftest to deal with Pointer Authentication - The usual bunch of cleanups and doc update
2021-11-24KVM: arm64: Move pkvm's special 32bit handling into a generic infrastructureMarc Zyngier1-0/+4
Protected KVM is trying to turn AArch32 exceptions into an illegal exception entry. Unfortunately, it does that in a way that is a bit abrupt, and too early for PSTATE to be available. Instead, move it to the fixup code, which is a more reasonable place for it. This will also be useful for the NV code. Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-11-22KVM: arm64: Stop mapping current thread_info at EL2Marc Zyngier1-1/+0
Now that we can track an equivalent of TIF_FOREIGN_FPSTATE, drop the mapping of current's thread_info at EL2. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-18KVM: arm64: pkvm: Pass vpcu instead of kvm to kvm_get_exit_handler_array()Marc Zyngier1-1/+1
Passing a VM pointer around is odd, and results in extra work on VHE. Follow the rest of the design that uses the vcpu instead, and let the nVHE code look into the struct kvm as required. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20211013120346.2926621-11-maz@kernel.org
2021-10-11KVM: arm64: Pass struct kvm to per-EC handlersFuad Tabba1-1/+1
We need struct kvm to check for protected VMs to be able to pick the right handlers for them in subsequent patches. Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211010145636.1950948-5-tabba@google.com
2021-10-11KVM: arm64: Move early handlers to per-EC handlersMarc Zyngier1-0/+16
Simplify the early exception handling by slicing the gigantic decoding tree into a more manageable set of functions, similar to what we have in handle_exit.c. This will also make the structure reusable for pKVM's own early exit handling. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20211010145636.1950948-4-tabba@google.com
2021-08-20Merge branch kvm-arm64/pkvm-fixed-features-prologue into kvmarm-master/nextMarc Zyngier3-12/+4
* kvm-arm64/pkvm-fixed-features-prologue: : Rework a bunch of common infrastructure as a prologue : to Fuad Tabba's protected VM fixed feature series. KVM: arm64: Upgrade trace_kvm_arm_set_dreg32() to 64bit KVM: arm64: Add config register bit definitions KVM: arm64: Add feature register flag definitions KVM: arm64: Track value of cptr_el2 in struct kvm_vcpu_arch KVM: arm64: Keep mdcr_el2's value as set by __init_el2_debug KVM: arm64: Restore mdcr_el2 from vcpu KVM: arm64: Refactor sys_regs.h,c for nVHE reuse KVM: arm64: Fix names of config register fields KVM: arm64: MDCR_EL2 is a 64-bit register KVM: arm64: Remove trailing whitespace in comment KVM: arm64: placeholder to check if VM is protected Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20KVM: arm64: Keep mdcr_el2's value as set by __init_el2_debugFuad Tabba1-4/+0
__init_el2_debug configures mdcr_el2 at initialization based on, among other things, available hardware support. Trap deactivation doesn't check that, so keep the initial value. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-8-tabba@google.com
2021-08-20KVM: arm64: Restore mdcr_el2 from vcpuFuad Tabba2-10/+6
On deactivating traps, restore the value of mdcr_el2 from the newly created and preserved host value vcpu context, rather than directly reading the hardware register. Up until and including this patch the two values are the same, i.e., the hardware register and the vcpu one. A future patch will be changing the value of mdcr_el2 on activating traps, and this ensures that its value will be restored. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-7-tabba@google.com
2021-08-20KVM: arm64: MDCR_EL2 is a 64-bit registerFuad Tabba1-1/+1
Fix the places in KVM that treat MDCR_EL2 as a 32-bit register. More recent features (e.g., FEAT_SPEv1p2) use bits above 31. No functional change intended. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-4-tabba@google.com
2021-08-20KVM: arm64: Unify stage-2 programming behind __load_stage2()Marc Zyngier2-5/+5
The protected mode relies on a separate helper to load the S2 context. Move over to the __load_guest_stage2() helper instead, and rename it to __load_stage2() to present a unified interface. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jade Alglave <jade.alglave@arm.com> Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210806113109.2475-5-will@kernel.org
2021-08-20KVM: arm64: Move kern_hyp_va() usage in __load_guest_stage2() into the callersMarc Zyngier2-2/+2
It is a bit awkward to use kern_hyp_va() in __load_guest_stage2(), specially as the helper is shared between VHE and nVHE. Instead, move the use of kern_hyp_va() in the nVHE code, and pass a pointer to the kvm->arch structure instead. Although this may look a bit awkward, it allows for some further simplification. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jade Alglave <jade.alglave@arm.com> Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210806113109.2475-4-will@kernel.org
2021-05-15KVM: arm64: Move __adjust_pc out of lineMarc Zyngier1-2/+1
In order to make it easy to call __adjust_pc() from the EL1 code (in the case of nVHE), rename it to __kvm_adjust_pc() and move it out of line. No expected functional change. Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org # 5.11
2021-04-01KVM: arm64: Log source when panicking from nVHE hypAndrew Scull1-3/+1
To aid with debugging, add details of the source of a panic from nVHE hyp. This is done by having nVHE hyp exit to nvhe_hyp_panic_handler() rather than directly to panic(). The handler will then add the extra details for debugging before panicking the kernel. If the panic was due to a BUG(), look up the metadata to log the file and line, if available, otherwise log an address that can be looked up in vmlinux. The hyp offset is also logged to allow other hyp VAs to be converted, similar to how the kernel offset is logged during a panic. __hyp_panic_string is now inlined since it no longer needs to be referenced as a symbol and the message is free to diverge between VHE and nVHE. The following is an example of the logs generated by a BUG in nVHE hyp. [ 46.754840] kvm [307]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/switch.c:242! [ 46.755357] kvm [307]: Hyp Offset: 0xfffea6c58e1e0000 [ 46.755824] Kernel panic - not syncing: HYP panic: [ 46.755824] PS:400003c9 PC:0000d93a82c705ac ESR:f2000800 [ 46.755824] FAR:0000000080080000 HPFAR:0000000000800800 PAR:0000000000000000 [ 46.755824] VCPU:0000d93a880d0000 [ 46.756960] CPU: 3 PID: 307 Comm: kvm-vcpu-0 Not tainted 5.12.0-rc3-00005-gc572b99cf65b-dirty #133 [ 46.757459] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 [ 46.758366] Call trace: [ 46.758601] dump_backtrace+0x0/0x1b0 [ 46.758856] show_stack+0x18/0x70 [ 46.759057] dump_stack+0xd0/0x12c [ 46.759236] panic+0x16c/0x334 [ 46.759426] arm64_kernel_unmapped_at_el0+0x0/0x30 [ 46.759661] kvm_arch_vcpu_ioctl_run+0x134/0x750 [ 46.759936] kvm_vcpu_ioctl+0x2f0/0x970 [ 46.760156] __arm64_sys_ioctl+0xa8/0xec [ 46.760379] el0_svc_common.constprop.0+0x60/0x120 [ 46.760627] do_el0_svc+0x24/0x90 [ 46.760766] el0_svc+0x2c/0x54 [ 46.760915] el0_sync_handler+0x1a4/0x1b0 [ 46.761146] el0_sync+0x170/0x180 [ 46.761889] SMP: stopping secondary CPUs [ 46.762786] Kernel Offset: 0x3e1cd2820000 from 0xffff800010000000 [ 46.763142] PHYS_OFFSET: 0xffffa9f680000000 [ 46.763359] CPU features: 0x00240022,61806008 [ 46.763651] Memory Limit: none [ 46.813867] ---[ end Kernel panic - not syncing: HYP panic: [ 46.813867] PS:400003c9 PC:0000d93a82c705ac ESR:f2000800 [ 46.813867] FAR:0000000080080000 HPFAR:0000000000800800 PAR:0000000000000000 [ 46.813867] VCPU:0000d93a880d0000 ]--- Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210318143311.839894-6-ascull@google.com
2021-03-09KVM: arm64: Ensure I-cache isolation between vcpus of a same VMMarc Zyngier1-1/+2
It recently became apparent that the ARMv8 architecture has interesting rules regarding attributes being used when fetching instructions if the MMU is off at Stage-1. In this situation, the CPU is allowed to fetch from the PoC and allocate into the I-cache (unless the memory is mapped with the XN attribute at Stage-2). If we transpose this to vcpus sharing a single physical CPU, it is possible for a vcpu running with its MMU off to influence another vcpu running with its MMU on, as the latter is expected to fetch from the PoU (and self-patching code doesn't flush below that level). In order to solve this, reuse the vcpu-private TLB invalidation code to apply the same policy to the I-cache, nuking it every time the vcpu runs on a physical CPU that ran another vcpu of the same VM in the past. This involve renaming __kvm_tlb_flush_local_vmid() to __kvm_flush_cpu_context(), and inserting a local i-cache invalidation there. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210303164505.68492-1-maz@kernel.org
2020-11-10KVM: arm64: Add basic hooks for injecting exceptions from EL2Marc Zyngier1-1/+1
Add the basic infrastructure to describe injection of exceptions into a guest. So far, nothing uses this code path. Signed-off-by: Marc Zyngier <maz@kernel.org>