tree 94f2f88610beefb87a9995c91a9452a867990d3a
parent 79962a5c8ba5b33f49d88a058e2124bf2ff3c034
author Andrew Jones <drjones@redhat.com> 1498926414 +0200
committer Marc Zyngier <marc.zyngier@arm.com> 1500988681 +0100

KVM: arm/arm64: PMU: Fix overflow interrupt injection

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: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>