Re: [PATCH 5.10.y] KVM: x86: Clear "has_error_code", not "error_code", for RM exception injection

[Sean Christopherson <seanjc@google.com>]

On Fri, May 10, 2024, Nicolas Saenz Julienne wrote:
> 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.

LOL, famous last words.

Acked-by: Sean Christopherson <seanjc@google.com>