diff options
| author | Marc Zyngier <maz@kernel.org> | 2021-09-19 14:09:49 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-09-20 12:43:34 +0100 |
| commit | e840f42a49925707fca90e6c7a4095118fdb8c4d (patch) | |
| tree | 127985ebfa09474234a135530d24021f0d3e850b /include/kvm | |
| parent | a49b50a3c1c3226d26e1dd11e8b763f27e477623 (diff) | |
KVM: arm64: Fix PMU probe ordering
Russell reported that since 5.13, KVM's probing of the PMU has
started to fail on his HW. As it turns out, there is an implicit
ordering dependency between the architectural PMU probing code and
and KVM's own probing. If, due to probe ordering reasons, KVM probes
before the PMU driver, it will fail to detect the PMU and prevent it
from being advertised to guests as well as the VMM.
Obviously, this is one probing too many, and we should be able to
deal with any ordering.
Add a callback from the PMU code into KVM to advertise the registration
of a host CPU PMU, allowing for any probing order.
Fixes: 5421db1be3b1 ("KVM: arm64: Divorce the perf code from oprofile helpers")
Reported-by: "Russell King (Oracle)" <linux@armlinux.org.uk>
Tested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/YUYRKVflRtUytzy5@shell.armlinux.org.uk
Cc: stable@vger.kernel.org
Diffstat (limited to 'include/kvm')
| -rw-r--r-- | include/kvm/arm_pmu.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 864b9997efb2..90f21898aad8 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -61,7 +61,6 @@ int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu); -int kvm_pmu_probe_pmuver(void); #else struct kvm_pmu { }; @@ -118,8 +117,6 @@ static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) return 0; } -static inline int kvm_pmu_probe_pmuver(void) { return 0xf; } - #endif #endif |