From: "Radim Krčmář" <rkrcmar@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Subject: [PATCH] KVM: nVMX: fix AD condition when handling EPT violation
Date: Thu, 13 Apr 2017 18:39:18 +0200 [thread overview]
Message-ID: <20170413163918.5830-1-rkrcmar@redhat.com> (raw)
I have introduced this bug when applying and simplifying Paolo's patch
as we agreed on the list. The original was "x &= ~y; if (z) x |= y;".
Here is the story of a bad workflow:
A maintainer was already testing with the intended change, but it was
applied only to a testing repo on a different machine. When the time
to push tested patches to kvm/next came, he realized that this change
was missing and quickly added it to the maintenance repo, didn't test
again (because the change is trivial, right), and pushed the world to
fire.
Fixes: ae1e2d1082ae ("kvm: nVMX: support EPT accessed/dirty bits")
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
arch/x86/kvm/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cfdb0d9389d1..837f6dd1ae9c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6221,7 +6221,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
* page table accesses are reads or writes.
*/
u64 eptp = nested_ept_get_cr3(vcpu);
- if (eptp & VMX_EPT_AD_ENABLE_BIT)
+ if (!(eptp & VMX_EPT_AD_ENABLE_BIT))
exit_qualification &= ~EPT_VIOLATION_ACC_WRITE;
}
--
2.12.0
next reply other threads:[~2017-04-13 16:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-13 16:39 Radim Krčmář [this message]
2017-04-14 5:10 ` Paolo Bonzini
2017-04-24 15:51 ` Radim Krčmář
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170413163918.5830-1-rkrcmar@redhat.com \
--to=rkrcmar@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®