Commit acdd8a4e authored Nov 13, 2022 by Marc Zyngier

KVM: arm64: PMU: Always advertise the CHAIN event



Even when the underlying HW doesn't offer the CHAIN event
(which happens with QEMU), we can always support it as we're
in control of the counter overflow.

Always advertise the event via PMCEID0_EL0.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221113163832.3154370-4-maz@kernel.org

parent bead0220

arch/arm64/kvm/pmu-emul.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -701,6 +701,8 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)

	if (!pmceid1) {		if (!pmceid1) {
	val = read_sysreg(pmceid0_el0);		val = read_sysreg(pmceid0_el0);
			/* always support CHAIN */
			val \|= BIT(ARMV8_PMUV3_PERFCTR_CHAIN);
	base = 0;		base = 0;
	} else {		} else {
	val = read_sysreg(pmceid1_el0);		val = read_sysreg(pmceid1_el0);