From: Sean Christopherson seanjc@google.com
commit 80962ec912db56d323883154efc2297473e692cb upstream.
Don't report an error code to L1 when synthesizing a nested VM-Exit and L2 is in Real Mode. Per Intel's SDM, regarding the error code valid bit:
This bit is always 0 if the VM exit occurred while the logical processor was in real-address mode (CR0.PE=0).
The bug was introduced by a recent fix for AMD's Paged Real Mode, which moved the error code suppression from the common "queue exception" path to the "inject exception" path, but missed VMX's "synthesize VM-Exit" path.
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: 20230322143300.2209476-3-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/vmx/nested.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3873,7 +3873,12 @@ static void nested_vmx_inject_exception_ exit_qual = 0; }
- if (ex->has_error_code) { + /* + * Unlike AMD's Paged Real Mode, which reports an error code on #PF + * VM-Exits even if the CPU is in Real Mode, Intel VMX never sets the + * "has error code" flags on VM-Exit if the CPU is in Real Mode. + */ + if (ex->has_error_code && is_protmode(vcpu)) { /* * Intel CPUs do not generate error codes with bits 31:16 set, * and more importantly VMX disallows setting bits 31:16 in the