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: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 51cfd73..1f99ecf 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -152,9 +152,14 @@
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];
};
};
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b38bd8b9..66ca98a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1870,17 +1870,16 @@
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) |
- (u32) c->regs[VCPU_REGS_RBX];
+ c->dst.val64 = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
+ (u32) c->regs[VCPU_REGS_RBX];
ctxt->eflags |= EFLG_ZF;
}
@@ -2616,7 +2615,7 @@
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) {
