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| author | Andrew Murray <andrew.murray@arm.com> | 2019-04-09 20:22:15 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2019-04-24 15:46:26 +0100 |
| commit | 435e53fb5e21ad1820c5c69f208304c0e5623d01 (patch) | |
| tree | b3ad2d97114ca99f78c6edcc76c7b0e1446df91b /virt | |
| parent | 3d91befbb3a0fcec6e1eebde45c8074b88cc9441 (diff) | |
| download | linux-435e53fb5e21ad1820c5c69f208304c0e5623d01.tar.gz linux-435e53fb5e21ad1820c5c69f208304c0e5623d01.tar.bz2 linux-435e53fb5e21ad1820c5c69f208304c0e5623d01.zip | |
arm64: KVM: Enable VHE support for :G/:H perf event modifiers
With VHE different exception levels are used between the host (EL2) and
guest (EL1) with a shared exception level for userpace (EL0). We can take
advantage of this and use the PMU's exception level filtering to avoid
enabling/disabling counters in the world-switch code. Instead we just
modify the counter type to include or exclude EL0 at vcpu_{load,put} time.
We also ensure that trapped PMU system register writes do not re-enable
EL0 when reconfiguring the backing perf events.
This approach completely avoids blackout windows seen with !VHE.
Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/arm.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index e960b91551d6..8b7ca101f0f7 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -382,6 +382,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_timer_vcpu_load(vcpu); kvm_vcpu_load_sysregs(vcpu); kvm_arch_vcpu_load_fp(vcpu); + kvm_vcpu_pmu_restore_guest(vcpu); if (single_task_running()) vcpu_clear_wfe_traps(vcpu); @@ -397,6 +398,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_vcpu_put_sysregs(vcpu); kvm_timer_vcpu_put(vcpu); kvm_vgic_put(vcpu); + kvm_vcpu_pmu_restore_host(vcpu); vcpu->cpu = -1; |