[PATCH 2/6] KVM: arm64: Fix AArch32 PMUv3 capping

Marc Zyngier
2021-01-14T10:57:48Z

We shouldn't expose *any* PMU capability when no PMU has been
configured for this VM.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/sys_regs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0c0832472c4a..ce08d28ab15c 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1048,8 +1048,8 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
} else if (id == SYS_ID_DFR0_EL1) {
/* Limit guests to PMUv3 for ARMv8.1 */
val = cpuid_feature_cap_perfmon_field(val,
- ID_DFR0_PERFMON_SHIFT,
- ID_DFR0_PERFMON_8_1);
+ ID_DFR0_PERFMON_SHIFT,
+ kvm_vcpu_has_pmu(vcpu) ? ID_DFR0_PERFMON_8_1 : 0);
}

return val;
--
2.29.2