Patch "KVM: x86: correct async page present tracepoint" has been added to the 3.18-stable tree

Patch "KVM: x86: correct async page present tracepoint" has been added to the 3.18-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    KVM: x86: correct async page present tracepoint

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-x86-correct-async-page-present-tracepoint.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Dec 21 10:55:04 CET 2017
From: Wanpeng Li <wanpeng.li@hotmail.com>
Date: Mon, 20 Mar 2017 21:18:55 -0700
Subject: KVM: x86: correct async page present tracepoint

From: Wanpeng Li <wanpeng.li@hotmail.com>


[ Upstream commit 24dccf83a121b8a4ad5c2ad383a8184ef6c266ee ]

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kvm/x86.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7783,11 +7783,11 @@ void kvm_arch_async_page_present(struct
 {
 	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)) {


Patches currently in stable-queue which might be from wanpeng.li@hotmail.com are

queue-3.18/kvm-x86-correct-async-page-present-tracepoint.patch