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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>
This commit is contained in:
Wanpeng Li 2017-03-20 21:18:55 -07:00 committed by Paolo Bonzini
parent fb6c819843
commit 24dccf83a1
1 changed files with 1 additions and 1 deletions
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2
arch/x86/kvm/x86.c
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@ -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)) {