This is a note to let you know that I've just added the patch titled
KVM: arm64: PMU: Restore the host's PMUSERENR_EL0
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm64-pmu-restore-the-host-s-pmuserenr_el0.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f39899708cd7e980bcfd95cbb25b4e7da7a73e17
Author: Reiji Watanabe <reijiw@xxxxxxxxxx>
Date: Fri Jun 2 19:50:34 2023 -0700
KVM: arm64: PMU: Restore the host's PMUSERENR_EL0
[ Upstream commit 8681f71759010503892f9e3ddb05f65c0f21b690 ]
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>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230603025035.3781797-2-reijiw@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 2208d79b18dea..081aca8f432ef 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -81,7 +81,12 @@ 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);
}
@@ -105,8 +110,12 @@ 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,
