Patch "KVM: x86: correct async page present tracepoint" has been added to the 4.9-stable tree
Subsystems (3)
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 4.9-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-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From foo@baz Thu Dec 21 09:02:40 CET 2017
From: Wanpeng Li <[email protected]>
Date: Mon, 20 Mar 2017 21:18:55 -0700
Subject: KVM: x86: correct async page present tracepoint
From: Wanpeng Li <[email protected]>
[ 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
--- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/kvm/x86.c +1 -1
@@ -8443,11 +8443,11 @@ 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 [email protected] are
queue-4.9/kvm-x86-correct-async-page-present-tracepoint.patch queue-4.9/kvm-vmx-fix-enable-vpid-conditions.patch