From ee122a7109e42313caadf6038ab773d1f68fcce1 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Tue, 28 Apr 2015 13:06:00 +0300 Subject: [PATCH] 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 Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index b32a38e6e287..e8c03be83e48 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -524,13 +524,9 @@ static void masked_increment(ulong *reg, ulong mask, int inc) 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) -- 2.34.1