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| author | Marc Zyngier <maz@kernel.org> | 2021-06-03 16:50:02 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-06-18 14:18:37 +0100 |
| commit | d0c94c49792cf780cbfefe29f81bb8c3b73bc76b (patch) | |
| tree | 632cd74cd7d4cbf7122bf3235de72d974359c9ae /arch/arm64/kvm/pmu-emul.c | |
| parent | 2a71fabf6a1bc9162a84e18d6ab991230ca4d588 (diff) | |
| download | linux-stable-d0c94c49792cf780cbfefe29f81bb8c3b73bc76b.tar.gz linux-stable-d0c94c49792cf780cbfefe29f81bb8c3b73bc76b.tar.bz2 linux-stable-d0c94c49792cf780cbfefe29f81bb8c3b73bc76b.zip | |
KVM: arm64: Restore PMU configuration on first run
Restoring a guest with an active virtual PMU results in no perf
counters being instanciated on the host side. Not quite what
you'd expect from a restore.
In order to fix this, force a writeback of PMCR_EL0 on the first
run of a vcpu (using a new request so that it happens once the
vcpu has been loaded). This will in turn create all the host-side
counters that were missing.
Reported-by: Jinank Jain <jinankj@amazon.de>
Tested-by: Jinank Jain <jinankj@amazon.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/87wnrbylxv.wl-maz@kernel.org
Link: https://lore.kernel.org/r/b53dfcf9bbc4db7f96154b1cd5188d72b9766358.camel@amazon.de
Diffstat (limited to 'arch/arm64/kvm/pmu-emul.c')
| -rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index ecc0d19c8cc1..f33825c995cb 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -851,6 +851,9 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) return -EINVAL; } + /* One-off reload of the PMU on first run */ + kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu); + return 0; } |