From aaa05f2437b9450f30b301db962ec4d45ec90fbb Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Mon, 2 Jun 2014 18:34:10 +0300 Subject: [PATCH] KVM: x86: Return error on cmpxchg16b emulation cmpxchg16b is currently unimplemented in the emulator. The least we can do is return error upon the emulation of this instruction. Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 3da8d82acb31..a151f8d24a1d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1999,6 +1999,9 @@ static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt) { u64 old = ctxt->dst.orig_val64; + if (ctxt->dst.bytes == 16) + return X86EMUL_UNHANDLEABLE; + if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) || ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) { *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0); @@ -4077,7 +4080,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, op->orig_val = op->val; break; case OpMem64: - ctxt->memop.bytes = 8; + ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8; goto mem_common; case OpAcc: op->type = OP_REG; -- 2.20.1