[PATCH v1] KVM: arm64: PMU: Restore the guest's EL0 event counting after migration

[Reiji Watanabe]

Currently, with VHE, KVM enables the EL0 event counting for the
guest on vcpu_load() or KVM enables it as a part of the PMU
register emulation process, when needed.  However, in the migration
case (with VHE), the same handling is lacking.  So, enable it on the
first KVM_RUN with VHE (after the migration) when needed.

Fixes: d0c94c49792c ("KVM: arm64: Restore PMU configuration on first run")
Cc: stable at vger.kernel.org
Signed-off-by: Reiji Watanabe <reijiw at google.com>
---
 arch/arm64/kvm/pmu-emul.c | 1 +
 arch/arm64/kvm/sys_regs.c | 1 -
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index c243b10f3e15..5eca0cdd961d 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -558,6 +558,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
 		for_each_set_bit(i, &mask, 32)
 			kvm_pmu_set_pmc_value(kvm_vcpu_idx_to_pmc(vcpu, i), 0, true);
 	}
+	kvm_vcpu_pmu_restore_guest(vcpu);
 }
 
 static bool kvm_pmu_counter_is_enabled(struct kvm_pmc *pmc)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1b2c161120be..34688918c811 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -794,7 +794,6 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 		if (!kvm_supports_32bit_el0())
 			val |= ARMV8_PMU_PMCR_LC;
 		kvm_pmu_handle_pmcr(vcpu, val);
-		kvm_vcpu_pmu_restore_guest(vcpu);
 	} else {
 		/* PMCR.P & PMCR.C are RAZ */
 		val = __vcpu_sys_reg(vcpu, PMCR_EL0)
-- 
2.40.0.348.gf938b09366-goog