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Commit 16518d5a authored by Avi Kivity's avatar Avi Kivity Committed by Marcelo Tosatti
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KVM: x86 emulator: fix regression with cmpxchg8b on i386 hosts 



operand::val and operand::orig_val are 32-bit on i386, whereas cmpxchg8b
operands are 64-bit.

Fix by adding val64 and orig_val64 union members to struct operand, and
using them where needed.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent d56557af

arch/x86/include/asm/kvm_emulate.h

+6 −1
Original line number Diff line number Diff line
@@ -152,9 +152,14 @@ struct x86_emulate_ops { 
struct operand {

	enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type;

	unsigned int bytes;

	unsigned long orig_val, *ptr;

	union {

		unsigned long orig_val;

		u64 orig_val64;

	};

	unsigned long *ptr;

	union {

		unsigned long val;

		u64 val64;

		char valptr[sizeof(unsigned long) + 2];

	};

};

arch/x86/kvm/emulate.c

+4 −5
Original line number Diff line number Diff line
@@ -1870,16 +1870,15 @@ static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt, 
			       struct x86_emulate_ops *ops)

{

	struct decode_cache *c = &ctxt->decode;

	u64 old = c->dst.orig_val;

	u64 old = c->dst.orig_val64;



	if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) ||

	    ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) {



		c->regs[VCPU_REGS_RAX] = (u32) (old >> 0);

		c->regs[VCPU_REGS_RDX] = (u32) (old >> 32);

		ctxt->eflags &= ~EFLG_ZF;

	} else {

		c->dst.val = ((u64)c->regs[VCPU_REGS_RCX] << 32) |

		c->dst.val64 = ((u64)c->regs[VCPU_REGS_RCX] << 32) |

			(u32) c->regs[VCPU_REGS_RBX];



		ctxt->eflags |= EFLG_ZF;
@@ -2616,7 +2615,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
					c->src.valptr, c->src.bytes);

		if (rc != X86EMUL_CONTINUE)

			goto done;

		c->src.orig_val = c->src.val;

		c->src.orig_val64 = c->src.val64;

	}



	if (c->src2.type == OP_MEM) {