- 30 Oct, 2023 16 commits
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Oliver Upton authored
* kvm-arm64/pmu_pmcr_n: : User-defined PMC limit, courtesy Raghavendra Rao Ananta : : Certain VMMs may want to reserve some PMCs for host use while running a : KVM guest. This was a bit difficult before, as KVM advertised all : supported counters to the guest. Userspace can now limit the number of : advertised PMCs by writing to PMCR_EL0.N, as KVM's sysreg and PMU : emulation enforce the specified limit for handling guest accesses. 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} KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0 KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handler KVM: arm64: PMU: Introduce helpers to set the guest's PMU Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* 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>
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Oliver Upton authored
* kvm-arm64/writable-id-regs: : Writable ID registers, courtesy of Jing Zhang : : This series significantly expands the architectural feature set that : userspace can manipulate via the ID registers. A new ioctl is defined : that makes the mutable fields in the ID registers discoverable to : userspace. KVM: selftests: Avoid using forced target for generating arm64 headers tools headers arm64: Fix references to top srcdir in Makefile KVM: arm64: selftests: Test for setting ID register from usersapce tools headers arm64: Update sysreg.h with kernel sources KVM: selftests: Generate sysreg-defs.h and add to include path perf build: Generate arm64's sysreg-defs.h and add to include path tools: arm64: Add a Makefile for generating sysreg-defs.h KVM: arm64: Document vCPU feature selection UAPIs KVM: arm64: Allow userspace to change ID_AA64ZFR0_EL1 KVM: arm64: Allow userspace to change ID_AA64PFR0_EL1 KVM: arm64: Allow userspace to change ID_AA64MMFR{0-2}_EL1 KVM: arm64: Allow userspace to change ID_AA64ISAR{0-2}_EL1 KVM: arm64: Bump up the default KVM sanitised debug version to v8p8 KVM: arm64: Reject attempts to set invalid debug arch version KVM: arm64: Advertise selected DebugVer in DBGDIDR.Version KVM: arm64: Use guest ID register values for the sake of emulation KVM: arm64: Document KVM_ARM_GET_REG_WRITABLE_MASKS KVM: arm64: Allow userspace to get the writable masks for feature ID registers Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
The 'prepare' target that generates the arm64 sysreg headers had no prerequisites, so it wound up forcing a rebuild of all KVM selftests each invocation. Add a rule for the generated headers and just have dependents use that for a prerequisite. Reported-by:
Nina Schoetterl-Glausch <nsg@linux.ibm.com> Fixes: 9697d84c ("KVM: selftests: Generate sysreg-defs.h and add to include path") Tested-by:
Nina Schoetterl-Glausch <nsg@linux.ibm.com> Link: https://lore.kernel.org/r/20231027005439.3142015-3-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
Aishwarya reports that KVM selftests for arm64 fail with the following error: | make[4]: Entering directory '/tmp/kci/linux/tools/testing/selftests/kvm' | Makefile:270: warning: overriding recipe for target | '/tmp/kci/linux/build/kselftest/kvm/get-reg-list' | Makefile:265: warning: ignoring old recipe for target | '/tmp/kci/linux/build/kselftest/kvm/get-reg-list' | make -C ../../../../tools/arch/arm64/tools/ | make[5]: Entering directory '/tmp/kci/linux/tools/arch/arm64/tools' | Makefile:10: ../tools/scripts/Makefile.include: No such file or directory | make[5]: *** No rule to make target '../tools/scripts/Makefile.include'. | Stop. It would appear that this only affects builds from the top-level Makefile (e.g. make kselftest-all), as $(srctree) is set to ".". Work around the issue by shadowing the kselftest naming scheme for the source tree variable. Reported-by:
Aishwarya TCV <aishwarya.tcv@arm.com> Fixes: 0359c946 ("tools headers arm64: Update sysreg.h with kernel sources") Link: https://lore.kernel.org/r/20231027005439.3142015-2-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* 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>
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Oliver Upton authored
* kvm-arm64/stage2-vhe-load: : Setup stage-2 MMU from vcpu_load() for VHE : : Unlike nVHE, there is no need to switch the stage-2 MMU around on guest : entry/exit in VHE mode as the host is running at EL2. Despite this KVM : reloads the stage-2 on every guest entry, which is needless. : : This series moves the setup of the stage-2 MMU context to vcpu_load() : when running in VHE mode. This is likely to be a win across the board, : but also allows us to remove an ISB on the guest entry path for systems : with one of the speculative AT errata. KVM: arm64: Move VTCR_EL2 into struct s2_mmu KVM: arm64: Load the stage-2 MMU context in kvm_vcpu_load_vhe() KVM: arm64: Rename helpers for VHE vCPU load/put KVM: arm64: Reload stage-2 for VMID change on VHE KVM: arm64: Restore the stage-2 context in VHE's __tlb_switch_to_host() KVM: arm64: Don't zero VTTBR in __tlb_switch_to_host() Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* kvm-arm64/nv-trap-fixes: : NV trap forwarding fixes, courtesy Miguel Luis and Marc Zyngier : : - Explicitly define the effects of HCR_EL2.NV on EL2 sysregs in the : NV trap encoding : : - Make EL2 registers that access AArch32 guest state UNDEF or RAZ/WI : where appropriate for NV guests 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 Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* kvm-arm64/smccc-filter-cleanups: : Cleanup the management of KVM's SMCCC maple tree : : Avoid the cost of maintaining the SMCCC filter maple tree if userspace : hasn't writen a rule to the filter. While at it, rip out the now : unnecessary VM flag to indicate whether or not the SMCCC filter was : configured. KVM: arm64: Use mtree_empty() to determine if SMCCC filter configured KVM: arm64: Only insert reserved ranges when SMCCC filter is used KVM: arm64: Add a predicate for testing if SMCCC filter is configured Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* kvm-arm64/pmevtyper-filter: : Fixes to KVM's handling of the PMUv3 exception level filtering bits : : - NSH (count at EL2) and M (count at EL3) should be stateful when the : respective EL is advertised in the ID registers but have no effect on : event counting. : : - NSU and NSK modify the event filtering of EL0 and EL1, respectively. : Though the kernel may not use these bits, other KVM guests might. : Implement these bits exactly as written in the pseudocode if EL3 is : advertised. KVM: arm64: Add PMU event filter bits required if EL3 is implemented KVM: arm64: Make PMEVTYPER<n>_EL0.NSH RES0 if EL2 isn't advertised Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* kvm-arm64/feature-flag-refactor: : vCPU feature flag cleanup : : Clean up KVM's handling of vCPU feature flags to get rid of the : vCPU-scoped bitmaps and remove failure paths from kvm_reset_vcpu(). KVM: arm64: Get rid of vCPU-scoped feature bitmap KVM: arm64: Remove unused return value from kvm_reset_vcpu() KVM: arm64: Hoist NV+SVE check into KVM_ARM_VCPU_INIT ioctl handler KVM: arm64: Prevent NV feature flag on systems w/o nested virt KVM: arm64: Hoist PAuth checks into KVM_ARM_VCPU_INIT ioctl KVM: arm64: Hoist SVE check into KVM_ARM_VCPU_INIT ioctl handler KVM: arm64: Hoist PMUv3 check into KVM_ARM_VCPU_INIT ioctl handler KVM: arm64: Add generic check for system-supported vCPU features Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
* kvm-arm64/misc: : Miscellaneous updates : : - Put an upper bound on the number of I-cache invalidations by : cacheline to avoid soft lockups : : - Get rid of bogus refererence count transfer for THP mappings : : - Do a local TLB invalidation on permission fault race : : - Fixes for page_fault_test KVM selftest : : - Add a tracepoint for detecting MMIO instructions unsupported by KVM 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: arm64: Do not transfer page refcount for THP adjustment KVM: arm64: Avoid soft lockups due to I-cache maintenance arm64: tlbflush: Rename MAX_TLBI_OPS KVM: arm64: Don't use kerneldoc comment for arm64_check_features() Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
It is a pretty well known fact that KVM does not support MMIO emulation without valid instruction syndrome information (ESR_EL2.ISV == 0). The current kvm_pr_unimpl() is pretty useless, as it contains zero context to relate the event to a vCPU. Replace it with a precise tracepoint that dumps the relevant context so the user can make sense of what the guest is doing. Acked-by:
Zenghui Yu <yuzenghui@huawei.com> Acked-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231026205306.3045075-1-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Zenghui Yu authored
It looks like a mistake to issue ISB *after* reading PAR_EL1, we should instead perform it between the AT instruction and the reads of PAR_EL1. As according to DDI0487J.a IJTYVP, "When an address translation instruction is executed, explicit synchronization is required to guarantee the result is visible to subsequent direct reads of PAR_EL1." Otherwise all guest_at testcases fail on my box with ==== Test Assertion Failure ==== aarch64/page_fault_test.c:142: par & 1 == 0 pid=1355864 tid=1355864 errno=4 - Interrupted system call 1 0x0000000000402853: vcpu_run_loop at page_fault_test.c:681 2 0x0000000000402cdb: run_test at page_fault_test.c:730 3 0x0000000000403897: for_each_guest_mode at guest_modes.c:100 4 0x00000000004019f3: for_each_test_and_guest_mode at page_fault_test.c:1105 5 (inlined by) main at page_fault_test.c:1131 6 0x0000ffffb153c03b: ?? ??:0 7 0x0000ffffb153c113: ?? ??:0 8 0x0000000000401aaf: _start at ??:? 0x1 != 0x0 (par & 1 != 0) Signed-off-by:
Zenghui Yu <yuzenghui@huawei.com> Acked-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231007124043.626-2-yuzenghui@huawei.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Zenghui Yu authored
Running page_fault_test on a Cortex A72 fails with Test: ro_memslot_no_syndrome_guest_cas Testing guest mode: PA-bits:40, VA-bits:48, 4K pages Testing memory backing src type: anonymous ==== Test Assertion Failure ==== aarch64/page_fault_test.c:117: guest_check_lse() pid=1944087 tid=1944087 errno=4 - Interrupted system call 1 0x00000000004028b3: vcpu_run_loop at page_fault_test.c:682 2 0x0000000000402d93: run_test at page_fault_test.c:731 3 0x0000000000403957: for_each_guest_mode at guest_modes.c:100 4 0x00000000004019f3: for_each_test_and_guest_mode at page_fault_test.c:1108 5 (inlined by) main at page_fault_test.c:1134 6 0x0000ffff868e503b: ?? ??:0 7 0x0000ffff868e5113: ?? ??:0 8 0x0000000000401aaf: _start at ??:? guest_check_lse() because we don't have a guest_prepare stage to check the presence of FEAT_LSE and skip the related guest_cas testing, and we end-up failing in GUEST_ASSERT(guest_check_lse()). Add the missing .guest_prepare() where it's indeed required. Signed-off-by:
Zenghui Yu <yuzenghui@huawei.com> Acked-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231007124043.626-1-yuzenghui@huawei.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
It is possible for multiple vCPUs to fault on the same IPA and attempt to resolve the fault. One of the page table walks will actually update the PTE and the rest will return -EAGAIN per our race detection scheme. KVM elides the TLB invalidation on the racing threads as the return value is nonzero. Before commit a12ab137 ("KVM: arm64: Use local TLBI on permission relaxation") KVM always used broadcast TLB invalidations when handling permission faults, which had the convenient property of making the stage-2 updates visible to all CPUs in the system. However now we do a local invalidation, and TLBI elision leads to the vCPU thread faulting again on the stale entry. Remember that the architecture permits the TLB to cache translations that precipitate a permission fault. Invalidate the TLB entry responsible for the permission fault if the stage-2 descriptor has been relaxed, regardless of which thread actually did the job. Acked-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230922223229.1608155-1-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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- 25 Oct, 2023 5 commits
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Marc Zyngier authored
When trapping accesses from a NV guest that tries to access SPSR_{irq,abt,und,fiq}, make sure we handle them as RAZ/WI, as if AArch32 wasn't implemented. This involves a bit of repainting to make the visibility handler more generic. Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231023095444.1587322-6-maz@kernel.orgSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Marc Zyngier authored
DBGVCR32_EL2, DACR32_EL2, IFSR32_EL2 and FPEXC32_EL2 are required to UNDEF when AArch32 isn't implemented, which is definitely the case when running NV. Given that this is the only case where these registers can trap, unconditionally inject an UNDEF exception. Signed-off-by:
Marc Zyngier <maz@kernel.org> Reviewed-by:
Oliver Upton <oliver.upton@linux.dev> Reviewed-by:
Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20231023095444.1587322-5-maz@kernel.orgSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Miguel Luis authored
Implement a fine grained approach in the _EL2 sysreg range instead of the current wide cast trap. This ensures that we don't mistakenly inject the wrong exception into the guest. [maz: commit message massaging, dropped secure and AArch32 registers from the list] Fixes: d0fc0a25 ("KVM: arm64: nv: Add trap forwarding for HCR_EL2") Reviewed-by:
Eric Auger <eric.auger@redhat.com> Signed-off-by:
Miguel Luis <miguel.luis@oracle.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231023095444.1587322-4-maz@kernel.orgSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Miguel Luis authored
Some _EL2 encodings are missing. Add them. Signed-off-by:
Miguel Luis <miguel.luis@oracle.com> Reviewed-by:
Eric Auger <eric.auger@redhat.com> [maz: dropped secure encodings] Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231023095444.1587322-3-maz@kernel.orgSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Miguel Luis authored
Some _EL12 encodings are missing. Add them. Reviewed-by:
Eric Auger <eric.auger@redhat.com> Signed-off-by:
Miguel Luis <miguel.luis@oracle.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231023095444.1587322-2-maz@kernel.orgSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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- 24 Oct, 2023 14 commits
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Raghavendra Rao Ananta authored
Add a vPMU test scenario to validate the userspace accesses for the registers PM{C,I}NTEN{SET,CLR} and PMOVS{SET,CLR} to ensure that KVM honors the architectural definitions of these registers for a given PMCR.N. Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-13-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
Add a new test case to the vpmu_counter_access test to check if PMU registers or their bits for unimplemented counters are not accessible or are RAZ, as expected. Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-12-rananta@google.com [Oliver: fix issues relating to exception return address] Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
Add a new test case to the vpmu_counter_access test to check if PMU registers or their bits for implemented counters on the vCPU are readable/writable as expected, and can be programmed to count events. Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-11-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
Introduce vpmu_counter_access test for arm64 platforms. The test configures PMUv3 for a vCPU, sets PMCR_EL0.N for the vCPU, and check if the guest can consistently see the same number of the PMU event counters (PMCR_EL0.N) that userspace sets. This test case is done with each of the PMCR_EL0.N values from 0 to 31 (With the PMCR_EL0.N values greater than the host value, the test expects KVM_SET_ONE_REG for the PMCR_EL0 to fail). Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-10-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Raghavendra Rao Ananta authored
Import kernel's include/linux/perf/arm_pmuv3.h, with the definition of PMEVN_SWITCH() additionally including an assert() for the 'default' case. The following patches will use macros defined in this header. Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-9-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
KVM does not yet support userspace modifying PMCR_EL0.N (With the previous patch, KVM ignores what is written by userspace). Add support userspace limiting PMCR_EL0.N. Disallow userspace to set PMCR_EL0.N to a value that is greater than the host value as KVM doesn't support more event counters than what the host HW implements. Also, make this register immutable after the VM has started running. To maintain the existing expectations, instead of returning an error, KVM returns a success for these two cases. Finally, ignore writes to read-only bits that are cleared on vCPU reset, and RES{0,1} bits (including writable bits that KVM doesn't support yet), as those bits shouldn't be modified (at least with the current KVM). Co-developed-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-8-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Raghavendra Rao Ananta authored
For unimplemented counters, the registers PM{C,I}NTEN{SET,CLR} and PMOVS{SET,CLR} are expected to have the corresponding bits RAZ. Hence to ensure correct KVM's PMU emulation, mask out the RES0 bits. Defer this work to the point that userspace can no longer change the number of advertised PMCs. Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-7-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Raghavendra Rao Ananta authored
For unimplemented counters, the bits in PM{C,I}NTEN{SET,CLR} and PMOVS{SET,CLR} registers are expected to RAZ. To honor this, explicitly implement the {get,set}_user functions for these registers to mask out unimplemented counters for userspace reads and writes. Co-developed-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-6-rananta@google.com [Oliver: drop unnecessary locking] Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Raghavendra Rao Ananta authored
The number of PMU event counters is indicated in PMCR_EL0.N. For a vCPU with PMUv3 configured, the value is set to the same value as the current PE on every vCPU reset. Unless the vCPU is pinned to PEs that has the PMU associated to the guest from the initial vCPU reset, the value might be different from the PMU's PMCR_EL0.N on heterogeneous PMU systems. Fix this by setting the vCPU's PMCR_EL0.N to the PMU's PMCR_EL0.N value. Track the PMCR_EL0.N per guest, as only one PMU can be set for the guest (PMCR_EL0.N must be the same for all vCPUs of the guest), and it is convenient for updating the value. To achieve this, the patch introduces a helper, kvm_arm_pmu_get_max_counters(), that reads the maximum number of counters from the arm_pmu associated to the VM. Make the function global as upcoming patches will be interested to know the value while setting the PMCR.N of the guest from userspace. KVM does not yet support userspace modifying PMCR_EL0.N. The following patch will add support for that. Reviewed-by:
Sebastian Ott <sebott@redhat.com> Co-developed-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-5-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
Add a helper to read a vCPU's PMCR_EL0, and use it whenever KVM reads a vCPU's PMCR_EL0. Currently, the PMCR_EL0 value is tracked per vCPU. The following patches will make (only) PMCR_EL0.N track per guest. Having the new helper will be useful to combine the PMCR_EL0.N field (tracked per guest) and the other fields (tracked per vCPU) to provide the value of PMCR_EL0. No functional change intended. Reviewed-by:
Sebastian Ott <sebott@redhat.com> Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Reviewed-by:
Eric Auger <eric.auger@redhat.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-4-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
Future changes to KVM's sysreg emulation will rely on having a valid PMU instance to determine the number of implemented counters (PMCR_EL0.N). This is earlier than when userspace is expected to modify the vPMU device attributes, where the default is selected today. Select the default PMU when handling KVM_ARM_VCPU_INIT such that it is available in time for sysreg emulation. Reviewed-by:
Sebastian Ott <sebott@redhat.com> Co-developed-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Marc Zyngier <maz@kernel.org> Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-3-rananta@google.com [Oliver: rewrite changelog] Signed-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
Suzuki noticed that KVM's PMU emulation is oblivious to the NSU and NSK event filter bits. On systems that have EL3 these bits modify the filter behavior in non-secure EL0 and EL1, respectively. Even though the kernel doesn't use these bits, it is entirely possible some other guest OS does. Additionally, it would appear that these and the M bit are required by the architecture if EL3 is implemented. Allow the EL3 event filter bits to be set if EL3 is advertised in the guest's ID register. Implement the behavior of NSU and NSK according to the pseudocode, and entirely ignore the M bit for perf event creation. Reported-by:
Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by:
Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20231019185618.3442949-3-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
The NSH bit, which filters event counting at EL2, is required by the architecture if an implementation has EL2. Even though KVM doesn't support nested virt yet, it makes no effort to hide the existence of EL2 from the ID registers. Userspace can, however, change the value of PFR0 to hide EL2. Align KVM's sysreg emulation with the architecture and make NSH RES0 if EL2 isn't advertised. Keep in mind the bit is ignored when constructing the backing perf event. While at it, build the event type mask using explicit field definitions instead of relying on ARMV8_PMU_EVTYPE_MASK. KVM probably should've been doing this in the first place, as it avoids changes to the aforementioned mask affecting sysreg emulation. Reviewed-by:
Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20231019185618.3442949-2-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Reiji Watanabe authored
Introduce new helper functions to set the guest's PMU (kvm->arch.arm_pmu) either to a default probed instance or to a caller requested one, and use it when the guest's PMU needs to be set. These helpers will make it easier for the following patches to modify the relevant code. No functional change intended. Reviewed-by:
Sebastian Ott <sebott@redhat.com> Signed-off-by:
Reiji Watanabe <reijiw@google.com> Signed-off-by:
Raghavendra Rao Ananta <rananta@google.com> Reviewed-by:
Eric Auger <eric.auger@redhat.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-2-rananta@google.comSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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- 23 Oct, 2023 1 commit
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Marc Zyngier authored
We currently have a global VTCR_EL2 value for each guest, even if the guest uses NV. This implies that the guest's own S2 must fit in the host's. This is odd, for multiple reasons: - the PARange values and the number of IPA bits don't necessarily match: you can have 33 bits of IPA space, and yet you can only describe 32 or 36 bits of PARange - When userspace set the IPA space, it creates a contract with the kernel saying "this is the IPA space I'm prepared to handle". At no point does it constraint the guest's own IPA space as long as the guest doesn't try to use a [I]PA outside of the IPA space set by userspace - We don't even try to hide the value of ID_AA64MMFR0_EL1.PARange. And then there is the consequence of the above: if a guest tries to create a S2 that has for input address something that is larger than the IPA space defined by the host, we inject a fatal exception. This is no good. For all intent and purposes, a guest should be able to have the S2 it really wants, as long as the *output* address of that S2 isn't outside of the IPA space. For that, we need to have a per-s2_mmu VTCR_EL2 setting, which allows us to represent the full PARange. Move the vctr field into the s2_mmu structure, which has no impact whatsoever, except for NV. Note that once we are able to override ID_AA64MMFR0_EL1.PARange from userspace, we'll also be able to restrict the size of the shadow S2 that NV uses. Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231012205108.3937270-1-maz@kernel.orgSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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- 20 Oct, 2023 4 commits
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Oliver Upton authored
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.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Oliver Upton authored
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.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Marc Zyngier authored
Naturally, a change to the VMID for an MMU implies a new value for VTTBR. Reload on VMID change in anticipation of loading stage-2 on vcpu_load() instead of every guest entry. Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231018233212.2888027-4-oliver.upton@linux.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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Marc Zyngier authored
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.devSigned-off-by:
Oliver Upton <oliver.upton@linux.dev>
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