From 199b5763d329b43c88f6ad539db8a6c6b42f8edb Mon Sep 17 00:00:00 2001 From: "Longpeng(Mike)" Date: Tue, 8 Aug 2017 12:05:32 +0800 Subject: KVM: add spinlock optimization framework If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) Signed-off-by: Paolo Bonzini --- arch/arm64/kvm/handle_exit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/kvm') diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 17d8a1677a0b..da57622cacca 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -84,7 +84,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; - kvm_vcpu_on_spin(vcpu); + kvm_vcpu_on_spin(vcpu, false); } else { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); vcpu->stat.wfi_exit_stat++; -- cgit v1.2.3-59-g8ed1b