[v2,01/10] arm/arm64: KVM: Fix ordering of timer/GIC on guest entry
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Message ID 1436378202-20224-2-git-send-email-marc.zyngier@arm.com
State New
Headers show

Commit Message

Marc Zyngier July 8, 2015, 5:56 p.m. UTC
As we now inject the timer interrupt when we're about to enter
the guest, it makes a lot more sense to make sure this happens
before the vgic code queues the pending interrupts.

Otherwise, we get the interrupt on the following exit, which is
not great for latency (and leads to all kind of bizarre issues
when using with active interrupts at the HW level).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/kvm/arm.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Patch
diff mbox

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index bc738d2..d605180 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -528,8 +528,8 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (vcpu->arch.pause)
 			vcpu_pause(vcpu);
 
-		kvm_vgic_flush_hwstate(vcpu);
 		kvm_timer_flush_hwstate(vcpu);
+		kvm_vgic_flush_hwstate(vcpu);
 
 		preempt_disable();
 		local_irq_disable();
@@ -545,8 +545,8 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
 			local_irq_enable();
 			preempt_enable();
-			kvm_timer_sync_hwstate(vcpu);
 			kvm_vgic_sync_hwstate(vcpu);
+			kvm_timer_sync_hwstate(vcpu);
 			continue;
 		}
 
@@ -588,9 +588,8 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		trace_kvm_exit(kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
 		preempt_enable();
 
-
-		kvm_timer_sync_hwstate(vcpu);
 		kvm_vgic_sync_hwstate(vcpu);
+		kvm_timer_sync_hwstate(vcpu);
 
 		ret = handle_exit(vcpu, run, ret);
 	}