KVM: x86 emulator: Add helpers for memory access using segmented addresses
Will help later adding proper segment checks.
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 50bffb9..8c38f6c 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -540,6 +540,15 @@
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 @@
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 @@
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 @@
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 @@
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 @@
}
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 @@
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;