KVM: x86: correct async page present tracepoint

After async pf setup successfully, there is a broadcast wakeup w/ special
token 0xffffffff which tells vCPU that it should wake up all processes
waiting for APFs though there is no real process waiting at the moment.

The async page present tracepoint print prematurely and fails to catch the
special token setup. This patch fixes it by moving the async page present
tracepoint after the special token setup.

Before patch:

qemu-system-x86-8499  [006] ...1  5973.473292: kvm_async_pf_ready: token 0x0 gva 0x0

After patch:

qemu-system-x86-8499  [006] ...1  5973.473292: kvm_async_pf_ready: token 0xffffffff gva 0x0

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d30ff491ecc76284f697d104674c8587572758ac..64697fe475c3cb0b005ee098d5e37974c646d53a 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8566,11 +8566,11 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
 {
        struct x86_exception fault;
 
-       trace_kvm_async_pf_ready(work->arch.token, work->gva);
        if (work->wakeup_all)
                work->arch.token = ~0; /* broadcast wakeup */
        else
                kvm_del_async_pf_gfn(vcpu, work->arch.gfn);
+       trace_kvm_async_pf_ready(work->arch.token, work->gva);
 
        if ((vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) &&
            !apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) {