KVM: x86: Fix update RCX/RDI/RSI on REP-string
When REP-string instruction is preceded with an address-size prefix,
ECX/EDI/ESI are used as the operation counter and pointers. When they are
updated, the high 32-bits of RCX/RDI/RSI are cleared, similarly to the way they
are updated on every 32-bit register operation. Fix it.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b32a38e..e8c03be 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -524,13 +524,9 @@
static inline void
register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc)
{
- ulong mask;
+ ulong *preg = reg_rmw(ctxt, reg);
- if (ctxt->ad_bytes == sizeof(unsigned long))
- mask = ~0UL;
- else
- mask = ad_mask(ctxt);
- masked_increment(reg_rmw(ctxt, reg), mask, inc);
+ assign_register(preg, *preg + inc, ctxt->ad_bytes);
}
static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)