From f7659f8bcdf86b119d945f3335f20eda219a23ff Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 4 Mar 2022 12:04:49 +0000 Subject: [PATCH] KVM: arm64: Only open the interrupt window on exit due to an interrupt Now that we properly account for interrupts taken whilst the guest was running, it becomes obvious that there is no need to open this accounting window if we didn't exit because of an interrupt. This saves a number of system register accesses and other barriers if we exited for any other reason (such as a trap, for example). Signed-off-by: Marc Zyngier Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20220304135914.1464721-1-maz@kernel.org --- arch/arm64/kvm/arm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index ecc5958e27fe..5254a97929f7 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -945,9 +945,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) * context synchronization event) is necessary to ensure that * pending interrupts are taken. */ - local_irq_enable(); - isb(); - local_irq_disable(); + if (ARM_EXCEPTION_CODE(ret) == ARM_EXCEPTION_IRQ) { + local_irq_enable(); + isb(); + local_irq_disable(); + } guest_timing_exit_irqoff(); -- 2.20.1