On Mon, 9 Oct 2023, Raghavendra Rao Ananta wrote:
u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu) { - return __vcpu_sys_reg(vcpu, PMCR_EL0); + u64 pmcr = __vcpu_sys_reg(vcpu, PMCR_EL0) & + ~(ARMV8_PMU_PMCR_N_MASK << ARMV8_PMU_PMCR_N_SHIFT); + + return pmcr | ((u64)vcpu->kvm->arch.pmcr_n << ARMV8_PMU_PMCR_N_SHIFT); } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ff0f7095eaca..c750722fbe4a 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -745,12 +745,8 @@ static u64 reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 pmcr; - /* No PMU available, PMCR_EL0 may UNDEF... */ - if (!kvm_arm_support_pmu_v3()) - return 0; - /* Only preserve PMCR_EL0.N, and reset the rest to 0 */ - pmcr = read_sysreg(pmcr_el0) & (ARMV8_PMU_PMCR_N_MASK << ARMV8_PMU_PMCR_N_SHIFT); + pmcr = kvm_vcpu_read_pmcr(vcpu) & (ARMV8_PMU_PMCR_N_MASK << ARMV8_PMU_PMCR_N_SHIFT);
pmcr = ((u64)vcpu->kvm->arch.pmcr_n << ARMV8_PMU_PMCR_N_SHIFT); Would that maybe make it more clear what is done here?