According to Intel SDM push of segment selectors is done in the following
manner: "if the operand size is 32-bits, either a zero-extended value is pushed
on the stack or the segment selector is written on the stack using a 16-bit
move. For the last case, all recent Core and Atom processors perform a 16-bit
move, leaving the upper portion of the stack location unmodified."
This patch modifies the behavior to match the core behavior.
Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 9dfd286..d45a57b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1797,6 +1797,10 @@ static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
int seg = ctxt->src2.val;
ctxt->src.val = get_segment_selector(ctxt, seg);
+ if (ctxt->op_bytes == 4) {
+ rsp_increment(ctxt, -2);
+ ctxt->op_bytes = 2;
+ }
return em_push(ctxt);
}
--
1.9.1
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