[RFC PATCH v2 09/19] KVM: arm/arm64: Move timer/vgic flush/sync under disabled irq

[Christoffer Dall]

As we are about to play tricks with the timer to be more lazy in saving
and restoring state, we need to move the timer sync and flush functions
under a disabled irq section and since we have to flush the vgic state
after the timer and PMU state, we do the whole flush/sync sequence with
disabled irqs.

The only downside is a slightly longer delay before being able to
process hardware interrupts and run softirqs.

Signed-off-by: Christoffer Dall <cdall at linaro.org>
---
 virt/kvm/arm/arm.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index a39a1e1..a49b19e 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -649,11 +649,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		kvm_pmu_flush_hwstate(vcpu);
 
+		local_irq_disable();
+
 		kvm_timer_flush_hwstate(vcpu);
 		kvm_vgic_flush_hwstate(vcpu);
 
-		local_irq_disable();
-
 		/*
 		 * If we have a singal pending, or need to notify a userspace
 		 * irqchip about timer or PMU level changes, then we exit (and
@@ -678,10 +678,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
 		    kvm_request_pending(vcpu)) {
 			vcpu->mode = OUTSIDE_GUEST_MODE;
-			local_irq_enable();
 			kvm_pmu_sync_hwstate(vcpu);
 			kvm_timer_sync_hwstate(vcpu);
 			kvm_vgic_sync_hwstate(vcpu);
+			local_irq_enable();
 			preempt_enable();
 			continue;
 		}
@@ -705,6 +705,16 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		kvm_arm_clear_debug(vcpu);
 
 		/*
+		 * We must sync the PMU and timer state before the vgic state so
+		 * that the vgic can properly sample the updated state of the
+		 * interrupt line.
+		 */
+		kvm_pmu_sync_hwstate(vcpu);
+		kvm_timer_sync_hwstate(vcpu);
+
+		kvm_vgic_sync_hwstate(vcpu);
+
+		/*
 		 * We may have taken a host interrupt in HYP mode (ie
 		 * while executing the guest). This interrupt is still
 		 * pending, as we haven't serviced it yet!
@@ -727,16 +737,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		guest_exit();
 		trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
 
-		/*
-		 * We must sync the PMU and timer state before the vgic state so
-		 * that the vgic can properly sample the updated state of the
-		 * interrupt line.
-		 */
-		kvm_pmu_sync_hwstate(vcpu);
-		kvm_timer_sync_hwstate(vcpu);
-
-		kvm_vgic_sync_hwstate(vcpu);
-
 		preempt_enable();
 
 		ret = handle_exit(vcpu, run, ret);
-- 
2.9.0