From ec0671d5684aca3326269439398e47790f1c6e7e Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Mon, 20 May 2019 16:18:08 +0800 Subject: KVM: LAPIC: Delay trace_kvm_wait_lapic_expire tracepoint to after vmexit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit wait_lapic_expire() call was moved above guest_enter_irqoff() because of its tracepoint, which violated the RCU extended quiescent state invoked by guest_enter_irqoff()[1][2]. This patch simply moves the tracepoint below guest_exit_irqoff() in vcpu_enter_guest(). Snapshot the delta before VM-Enter, but trace it after VM-Exit. This can help us to move wait_lapic_expire() just before vmentry in the later patch. [1] Commit 8b89fe1f6c43 ("kvm: x86: move tracepoints outside extended quiescent state") [2] https://patchwork.kernel.org/patch/7821111/ Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Liran Alon Suggested-by: Sean Christopherson Signed-off-by: Wanpeng Li [Track whether wait_lapic_expire was called, and do not invoke the tracepoint if not. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f3c0f2b63d76..7a26aa5b0861 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7980,6 +7980,13 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) ++vcpu->stat.exits; guest_exit_irqoff(); + if (lapic_in_kernel(vcpu)) { + s64 delta = vcpu->arch.apic->lapic_timer.advance_expire_delta; + if (delta != S64_MIN) { + trace_kvm_wait_lapic_expire(vcpu->vcpu_id, delta); + vcpu->arch.apic->lapic_timer.advance_expire_delta = S64_MIN; + } + } local_irq_enable(); preempt_enable(); -- cgit v1.2.3