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KVM: x86 emulator: emulate LEAVE

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Opcode c9; used by some variants of Windows during boot, in big real mode.

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2012-06-07 17:49:24 +03:00
parent b8405c184b
commit f47cfa3174
1 changed files with 24 additions and 1 deletions
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25
arch/x86/kvm/emulate.c
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@ -433,11 +433,27 @@ static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
return ctxt->ops->intercept(ctxt, &info, stage);
}
static void assign_masked(ulong *dest, ulong src, ulong mask)
{
*dest = (*dest & ~mask) | (src & mask);
}
static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
{
return (1UL << (ctxt->ad_bytes << 3)) - 1;
}
static ulong stack_mask(struct x86_emulate_ctxt *ctxt)
{
u16 sel;
struct desc_struct ss;
if (ctxt->mode == X86EMUL_MODE_PROT64)
return ~0UL;
ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS);
return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */
}
/* Access/update address held in a register, based on addressing mode. */
static inline unsigned long
address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg)
@ -1560,6 +1576,13 @@ static int em_popf(struct x86_emulate_ctxt *ctxt)
return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes);
}
static int em_leave(struct x86_emulate_ctxt *ctxt)
{
assign_masked(&ctxt->regs[VCPU_REGS_RSP], ctxt->regs[VCPU_REGS_RBP],
stack_mask(ctxt));
return emulate_pop(ctxt, &ctxt->regs[VCPU_REGS_RBP], ctxt->op_bytes);
}
static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
{
int seg = ctxt->src2.val;
@ -3582,7 +3605,7 @@ static struct opcode opcode_table[256] = {
I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
G(ByteOp, group11), G(0, group11),
/* 0xC8 - 0xCF */
N, N, N, I(ImplicitOps | Stack, em_ret_far),
N, I(Stack, em_leave), N, I(ImplicitOps | Stack, em_ret_far),
D(ImplicitOps), DI(SrcImmByte, intn),
D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
/* 0xD0 - 0xD7 */