[PATCH 2/3] KVM: x86: Set error code to segment selector on LLDT/LTR non-canonical #GP

From: Sean Christopherson
Date: Mon Jul 11 2022 - 19:28:25 EST


When injecting a #GP on LLDT/LTR due to a non-canonical LDT/TSS base, set
the error code to the selector. Intel SDM's says nothing about the #GP,
but AMD's APM explicitly states that both LLDT and LTR set the error code
to the selector, not zero.

Note, a non-canonical memory operand on LLDT/LTR does generate a #GP(0),
but the KVM code in question is specific to the base from the descriptor.

Fixes: e37a75a13cda ("KVM: x86: Emulator ignores LDTR/TR extended base on LLDT/LTR")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 09e4b67b881f..bd9e9c5627d0 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1736,8 +1736,8 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
if (ret != X86EMUL_CONTINUE)
return ret;
if (emul_is_noncanonical_address(get_desc_base(&seg_desc) |
- ((u64)base3 << 32), ctxt))
- return emulate_gp(ctxt, 0);
+ ((u64)base3 << 32), ctxt))
+ return emulate_gp(ctxt, err_code);
}

if (seg == VCPU_SREG_TR) {
--
2.37.0.144.g8ac04bfd2-goog