From: Laurent Vivier <[email protected]>
Split the decoding process into a new function x86_decode_insn().
Signed-off-by: Laurent Vivier <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
---
drivers/kvm/x86_emulate.c | 77 +++++++++++++++++++++++++++++++--------------
1 files changed, 53 insertions(+), 24 deletions(-)
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index f946182..f20534b 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -517,20 +517,16 @@ static int test_cc(unsigned int condition, unsigned int flags)
}
int
-x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
+x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
struct decode_cache *c = &ctxt->decode;
u8 sib, rex_prefix = 0;
unsigned int i;
int rc = 0;
- unsigned long cr2 = ctxt->cr2;
int mode = ctxt->mode;
int index_reg = 0, base_reg = 0, scale, rip_relative = 0;
- int no_wb = 0;
- u64 msr_data;
/* Shadow copy of register state. Committed on successful emulation. */
- unsigned long _eflags = ctxt->eflags;
memset(c, 0, sizeof(struct decode_cache));
c->eip = ctxt->vcpu->rip;
@@ -622,8 +618,10 @@ done_prefixes:
}
/* Unrecognised? */
- if (c->d == 0)
- goto cannot_emulate;
+ if (c->d == 0) {
+ DPRINTF("Cannot emulate %02x\n", c->b);
+ return -1;
+ }
}
/* ModRM and SIB bytes. */
@@ -776,7 +774,6 @@ done_prefixes:
}
if (c->ad_bytes != 8)
c->modrm_ea = (u32)c->modrm_ea;
- cr2 = c->modrm_ea;
modrm_done:
;
}
@@ -838,13 +835,6 @@ done_prefixes:
break;
}
c->src.type = OP_MEM;
- c->src.ptr = (unsigned long *)cr2;
- c->src.val = 0;
- if ((rc = ops->read_emulated((unsigned long)c->src.ptr,
- &c->src.val,
- c->src.bytes, ctxt->vcpu)) != 0)
- goto done;
- c->src.orig_val = c->src.val;
break;
case SrcImm:
c->src.type = OP_IMM;
@@ -877,7 +867,7 @@ done_prefixes:
switch (c->d & DstMask) {
case ImplicitOps:
/* Special instructions do their own operand decoding. */
- goto special_insn;
+ return 0;
case DstReg:
c->dst.type = OP_REG;
if ((c->d & ByteOp)
@@ -905,14 +895,54 @@ done_prefixes:
}
break;
case DstMem:
- c->dst.type = OP_MEM;
- c->dst.ptr = (unsigned long *)cr2;
- c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
- c->dst.val = 0;
if ((c->d & ModRM) && c->modrm_mod == 3) {
c->dst.type = OP_REG;
break;
}
+ c->dst.type = OP_MEM;
+ break;
+ }
+
+done:
+ return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
+}
+
+int
+x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
+{
+ unsigned long cr2 = ctxt->cr2;
+ int no_wb = 0;
+ u64 msr_data;
+ unsigned long _eflags = ctxt->eflags;
+ struct decode_cache *c = &ctxt->decode;
+ int rc;
+
+ rc = x86_decode_insn(ctxt, ops);
+ if (rc)
+ return rc;
+
+ if ((c->d & ModRM) && (c->modrm_mod != 3))
+ cr2 = c->modrm_ea;
+
+ if (c->src.type == OP_MEM) {
+ c->src.ptr = (unsigned long *)cr2;
+ c->src.val = 0;
+ if ((rc = ops->read_emulated((unsigned long)c->src.ptr,
+ &c->src.val,
+ c->src.bytes,
+ ctxt->vcpu)) != 0)
+ goto done;
+ c->src.orig_val = c->src.val;
+ }
+
+ if ((c->d & DstMask) == ImplicitOps)
+ goto special_insn;
+
+
+ if (c->dst.type == OP_MEM) {
+ c->dst.ptr = (unsigned long *)cr2;
+ c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+ c->dst.val = 0;
if (c->d & BitOp) {
unsigned long mask = ~(c->dst.bytes * 8 - 1);
@@ -925,7 +955,6 @@ done_prefixes:
&c->dst.val,
c->dst.bytes, ctxt->vcpu)) != 0))
goto done;
- break;
}
c->dst.orig_val = c->dst.val;
@@ -983,7 +1012,7 @@ done_prefixes:
emulate_2op_SrcV("cmp", c->src, c->dst, _eflags);
break;
case 0x63: /* movsxd */
- if (mode != X86EMUL_MODE_PROT64)
+ if (ctxt->mode != X86EMUL_MODE_PROT64)
goto cannot_emulate;
c->dst.val = (s32) c->src.val;
break;
@@ -1041,7 +1070,7 @@ done_prefixes:
break;
case 0x8f: /* pop (sole member of Grp1a) */
/* 64-bit mode: POP always pops a 64-bit operand. */
- if (mode == X86EMUL_MODE_PROT64)
+ if (ctxt->mode == X86EMUL_MODE_PROT64)
c->dst.bytes = 8;
if ((rc = ops->read_std(register_address(
ctxt->ss_base,
@@ -1152,7 +1181,7 @@ done_prefixes:
break;
case 6: /* push */
/* 64-bit mode: PUSH always pushes a 64-bit operand. */
- if (mode == X86EMUL_MODE_PROT64) {
+ if (ctxt->mode == X86EMUL_MODE_PROT64) {
c->dst.bytes = 8;
if ((rc = ops->read_std(
(unsigned long)c->dst.ptr,
--
1.5.3.7
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