This is a note to let you know that I've just added the patch titled
KVM: x86: Clear "has_error_code", not "error_code", for RM exception injection
to the 5.15-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-clear-has_error_code-not-error_code-for-rm-exception-injection.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6c41468c7c12d74843bb414fc00307ea8a6318c3 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Wed, 22 Mar 2023 07:32:59 -0700
Subject: KVM: x86: Clear "has_error_code", not "error_code", for RM exception injection
From: Sean Christopherson <seanjc@xxxxxxxxxx>
commit 6c41468c7c12d74843bb414fc00307ea8a6318c3 upstream.
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@xxxxxxxxxxxxxxx
Cc: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20230322143300.2209476-2-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
[nsaenz: backport to 5.15.y]
Signed-off-by: Nicolas Saenz Julienne <nsaenz@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9134,13 +9134,20 @@ int kvm_check_nested_events(struct kvm_v
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;
static_call(kvm_x86_queue_exception)(vcpu);
}
Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are
queue-5.15/kvm-x86-clear-has_error_code-not-error_code-for-rm-exception-injection.patch
