Restore the host's PMUSERENR_EL0 value instead of clearing it,
before returning back to userspace, as the host's EL0 might have
a direct access to PMU registers (some bits of PMUSERENR_EL0 for
might not be zero for the host EL0).
Fixes: 83a7a4d643d3 ("arm64: perf: Enable PMU counter userspace access for perf event")
Signed-off-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
---
arch/arm64/kvm/hyp/include/hyp/switch.h | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index e78a08a72a3c..51229d847103 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -82,7 +82,12 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
* EL1 instead of being trapped to EL2.
*/
if (kvm_arm_support_pmu_v3()) {
+ struct kvm_cpu_context *hctxt;
+
write_sysreg(0, pmselr_el0);
+
+ hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+ ctxt_sys_reg(hctxt, PMUSERENR_EL0) = read_sysreg(pmuserenr_el0);
write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
}
@@ -106,8 +111,12 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu)
write_sysreg(vcpu->arch.mdcr_el2_host, mdcr_el2);
write_sysreg(0, hstr_el2);
- if (kvm_arm_support_pmu_v3())
- write_sysreg(0, pmuserenr_el0);
+ if (kvm_arm_support_pmu_v3()) {
+ struct kvm_cpu_context *hctxt;
+
+ hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+ write_sysreg(ctxt_sys_reg(hctxt, PMUSERENR_EL0), pmuserenr_el0);
+ }
if (cpus_have_final_cap(ARM64_SME)) {
sysreg_clear_set_s(SYS_HFGRTR_EL2, 0,
--
2.41.0.rc0.172.g3f132b7071-goog
