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| author | Paolo Bonzini <pbonzini@redhat.com> | 2023-03-27 10:03:16 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-03-27 10:03:16 -0400 |
| commit | 8607daa2145f277c2548eee22e9fa45dfecd8dea (patch) | |
| tree | da3d966ea5889ef16d11bcf3fff06239b22cc8ad /arch/arm64/kvm/pmu-emul.c | |
| parent | f3e707413dbe3920a972d0c2b51175180e7de36b (diff) | |
| parent | 8c2e8ac8ad4be68409e806ce1cc78fc7a04539f3 (diff) | |
Merge tag 'kvmarm-fixes-6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 6.3, part #2
Fixes for a rather interesting set of bugs relating to the MMU:
- Read the MMU notifier seq before dropping the mmap lock to guard
against reading a potentially stale VMA
- Disable interrupts when walking user page tables to protect against
the page table being freed
- Read the MTE permissions for the VMA within the mmap lock critical
section, avoiding the use of a potentally stale VMA pointer
Additionally, some fixes targeting the vPMU:
- Return the sum of the current perf event value and PMC snapshot for
reads from userspace
- Don't save the value of guest writes to PMCR_EL0.{C,P}, which could
otherwise lead to userspace erroneously resetting the vPMU during VM
save/restore
Diffstat (limited to 'arch/arm64/kvm/pmu-emul.c')
| -rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 24908400e190..c243b10f3e15 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -538,7 +538,8 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) if (!kvm_pmu_is_3p5(vcpu)) val &= ~ARMV8_PMU_PMCR_LP; - __vcpu_sys_reg(vcpu, PMCR_EL0) = val; + /* The reset bits don't indicate any state, and shouldn't be saved. */ + __vcpu_sys_reg(vcpu, PMCR_EL0) = val & ~(ARMV8_PMU_PMCR_C | ARMV8_PMU_PMCR_P); if (val & ARMV8_PMU_PMCR_E) { kvm_pmu_enable_counter_mask(vcpu, |