• Andrew Jones's avatar
    KVM: arm/arm64: PMU: Fix overflow interrupt injection · d9f89b4e
    Andrew Jones authored
    kvm_pmu_overflow_set() is called from perf's interrupt handler,
    making the call of kvm_vgic_inject_irq() from it introduced with
    "KVM: arm/arm64: PMU: remove request-less vcpu kick" a really bad
    idea, as it's quite easy to try and retake a lock that the
    interrupted context is already holding. The fix is to use a vcpu
    kick, leaving the interrupt injection to kvm_pmu_sync_hwstate(),
    like it was doing before the refactoring. We don't just revert,
    though, because before the kick was request-less, leaving the vcpu
    exposed to the request-less vcpu kick race, and also because the
    kick was used unnecessarily from register access handlers.
    Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
    Signed-off-by: default avatarAndrew Jones <drjones@redhat.com>
    Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
arm_pmu.h 4.12 KB