From: Nicolas Saenz Julienne <nsaenz@amazon.com>
To: <stable@vger.kernel.org>
Cc: Sean Christopherson <seanjc@google.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"Nicolas Saenz Julienne" <nsaenz@amazon.com>
Subject: [PATCH 5.10.y] KVM: x86: Clear "has_error_code", not "error_code", for RM exception injection
Date: Fri, 10 May 2024 13:12:13 +0000 [thread overview]
Message-ID: <20240510131213.21633-1-nsaenz@amazon.com> (raw)
In-Reply-To: <2023041135-yippee-shabby-b9ad@gregkh>
From: Sean Christopherson <seanjc@google.com>
When injecting an exception into a vCPU in Real Mode, suppress the error
code by clearing the flag that tracks whether the error code is valid, not
by clearing the error code itself. The "typo" was introduced by recent
fix for SVM's funky Paged Real Mode.
Opportunistically hoist the logic above the tracepoint so that the trace
is coherent with respect to what is actually injected (this was also the
behavior prior to the buggy commit).
Fixes: b97f07458373 ("KVM: x86: determine if an exception has an error code only when injecting it.")
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230322143300.2209476-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 6c41468c7c12d74843bb414fc00307ea8a6318c3)
[nsaenz: backport to 5.10.y]
Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Conflicts:
arch/x86/kvm/x86.c: Patch offsets had to be corrected.
---
Testing: Kernel build and VM launch with KVM.
Unfortunately I don't have a repro for the issue this solves, but the
patch is straightforward, so I believe the testing above is good enough.
arch/x86/kvm/x86.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8e0b957c6219..bc295439360e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8501,13 +8501,20 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
static void kvm_inject_exception(struct kvm_vcpu *vcpu)
{
+ /*
+ * Suppress the error code if the vCPU is in Real Mode, as Real Mode
+ * exceptions don't report error codes. The presence of an error code
+ * is carried with the exception and only stripped when the exception
+ * is injected as intercepted #PF VM-Exits for AMD's Paged Real Mode do
+ * report an error code despite the CPU being in Real Mode.
+ */
+ vcpu->arch.exception.has_error_code &= is_protmode(vcpu);
+
trace_kvm_inj_exception(vcpu->arch.exception.nr,
vcpu->arch.exception.has_error_code,
vcpu->arch.exception.error_code,
vcpu->arch.exception.injected);
- if (vcpu->arch.exception.error_code && !is_protmode(vcpu))
- vcpu->arch.exception.error_code = false;
kvm_x86_ops.queue_exception(vcpu);
}
--
2.40.1
next prev parent reply other threads:[~2024-05-10 13:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-11 11:00 FAILED: patch "[PATCH] KVM: x86: Clear "has_error_code", not "error_code", for RM" failed to apply to 5.10-stable tree gregkh
2024-05-10 13:12 ` Nicolas Saenz Julienne [this message]
2024-05-10 15:42 ` [PATCH 5.10.y] KVM: x86: Clear "has_error_code", not "error_code", for RM exception injection Sean Christopherson
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=20240510131213.21633-1-nsaenz@amazon.com \
--to=nsaenz@amazon.com \
--cc=mlevitsk@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=stable@vger.kernel.org \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).