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KVM: x86 emulator: Add helpers for memory access using segmented addresses

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Will help later adding proper segment checks.

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2011-03-31 16:52:26 +02:00
parent e3e9ed3d2c
commit 3ca3ac4dae
1 changed files with 52 additions and 23 deletions
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75
arch/x86/kvm/emulate.c
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@ -540,6 +540,15 @@ static int emulate_nm(struct x86_emulate_ctxt *ctxt)
return emulate_exception(ctxt, NM_VECTOR, 0, false);
}
static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
struct segmented_address addr,
void *data,
unsigned size)
{
return ctxt->ops->read_std(linear(ctxt, addr), data, size, ctxt->vcpu,
&ctxt->exception);
}
static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops,
unsigned long eip, u8 *dest)
@ -604,13 +613,11 @@ static int read_descriptor(struct x86_emulate_ctxt *ctxt,
if (op_bytes == 2)
op_bytes = 3;
*address = 0;
rc = ops->read_std(linear(ctxt, addr), (unsigned long *)size, 2,
ctxt->vcpu, &ctxt->exception);
rc = segmented_read_std(ctxt, addr, size, 2);
if (rc != X86EMUL_CONTINUE)
return rc;
addr.ea += 2;
rc = ops->read_std(linear(ctxt, addr), address, op_bytes,
ctxt->vcpu, &ctxt->exception);
rc = segmented_read_std(ctxt, addr, address, op_bytes);
return rc;
}
@ -950,6 +957,32 @@ static int read_emulated(struct x86_emulate_ctxt *ctxt,
return X86EMUL_CONTINUE;
}
static int segmented_read(struct x86_emulate_ctxt *ctxt,
struct segmented_address addr,
void *data,
unsigned size)
{
return read_emulated(ctxt, ctxt->ops, linear(ctxt, addr), data, size);
}
static int segmented_write(struct x86_emulate_ctxt *ctxt,
struct segmented_address addr,
const void *data,
unsigned size)
{
return ctxt->ops->write_emulated(linear(ctxt, addr), data, size,
&ctxt->exception, ctxt->vcpu);
}
static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
struct segmented_address addr,
const void *orig_data, const void *data,
unsigned size)
{
return ctxt->ops->cmpxchg_emulated(linear(ctxt, addr), orig_data, data,
size, &ctxt->exception, ctxt->vcpu);
}
static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops,
unsigned int size, unsigned short port,
@ -1197,20 +1230,16 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
break;
case OP_MEM:
if (c->lock_prefix)
rc = ops->cmpxchg_emulated(
linear(ctxt, c->dst.addr.mem),
&c->dst.orig_val,
&c->dst.val,
c->dst.bytes,
&ctxt->exception,
ctxt->vcpu);
rc = segmented_cmpxchg(ctxt,
c->dst.addr.mem,
&c->dst.orig_val,
&c->dst.val,
c->dst.bytes);
else
rc = ops->write_emulated(
linear(ctxt, c->dst.addr.mem),
&c->dst.val,
c->dst.bytes,
&ctxt->exception,
ctxt->vcpu);
rc = segmented_write(ctxt,
c->dst.addr.mem,
&c->dst.val,
c->dst.bytes);
if (rc != X86EMUL_CONTINUE)
return rc;
break;
@ -1249,7 +1278,7 @@ static int emulate_pop(struct x86_emulate_ctxt *ctxt,
addr.ea = register_address(c, c->regs[VCPU_REGS_RSP]);
addr.seg = VCPU_SREG_SS;
rc = read_emulated(ctxt, ops, linear(ctxt, addr), dest, len);
rc = segmented_read(ctxt, addr, dest, len);
if (rc != X86EMUL_CONTINUE)
return rc;
@ -3440,16 +3469,16 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
}
if ((c->src.type == OP_MEM) && !(c->d & NoAccess)) {
rc = read_emulated(ctxt, ops, linear(ctxt, c->src.addr.mem),
c->src.valptr, c->src.bytes);
rc = segmented_read(ctxt, c->src.addr.mem,
c->src.valptr, c->src.bytes);
if (rc != X86EMUL_CONTINUE)
goto done;
c->src.orig_val64 = c->src.val64;
}
if (c->src2.type == OP_MEM) {
rc = read_emulated(ctxt, ops, linear(ctxt, c->src2.addr.mem),
&c->src2.val, c->src2.bytes);
rc = segmented_read(ctxt, c->src2.addr.mem,
&c->src2.val, c->src2.bytes);
if (rc != X86EMUL_CONTINUE)
goto done;
}
@ -3460,7 +3489,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
if ((c->dst.type == OP_MEM) && !(c->d & Mov)) {
/* optimisation - avoid slow emulated read if Mov */
rc = read_emulated(ctxt, ops, linear(ctxt, c->dst.addr.mem),
rc = segmented_read(ctxt, c->dst.addr.mem,
&c->dst.val, c->dst.bytes);
if (rc != X86EMUL_CONTINUE)
goto done;