[PATCH v9 15/22] KVM: arm64: Allow kvm_vcpu_pmu_resync_el0() to resync filters in process context

[Colton Lewis]

Previously, kvm_vcpu_pmu_resync_el0() only scheduled
KVM_REQ_RESYNC_PMU_EL0 when called from interrupt context (such as an
IPI reprogramming host perf events). When perf_pmu_resched_update() is
invoked synchronously from process context during vCPU load/put to
reschedule host events around guest-reserved counters,
armv8pmu_enable_event() calls kvm_set_pmu_events() and
kvm_vcpu_pmu_resync_el0() in process context.

Update kvm_vcpu_pmu_resync_el0() to call kvm_vcpu_pmu_restore_guest()
directly when not in interrupt context so that newly rescheduled host
perf events have their EL0 exclusion filters applied immediately.

Signed-off-by: Colton Lewis <coltonlewis@xxxxxxxxxx>
---
 arch/arm64/kvm/pmu.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
index 6f60f86fad387..a8214ab52fcb5 100644
--- a/arch/arm64/kvm/pmu.c
+++ b/arch/arm64/kvm/pmu.c
@@ -213,14 +213,17 @@ void kvm_vcpu_pmu_resync_el0(void)
 {
 	struct kvm_vcpu *vcpu;
 
-	if (!has_vhe() || !in_interrupt())
+	if (!has_vhe())
 		return;
 
 	vcpu = kvm_get_running_vcpu();
 	if (!vcpu)
 		return;
 
-	kvm_make_request(KVM_REQ_RESYNC_PMU_EL0, vcpu);
+	if (in_interrupt())
+		kvm_make_request(KVM_REQ_RESYNC_PMU_EL0, vcpu);
+	else
+		kvm_vcpu_pmu_restore_guest(vcpu);
 }
 
 void kvm_host_pmu_init(struct arm_pmu *pmu)
-- 
2.56.0.rc1.310.g51773c2048-goog