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Commit 3ca3ac4d authored by Avi Kivity's avatar Avi Kivity
Browse files

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



Will help later adding proper segment checks.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent e3e9ed3d

arch/x86/kvm/emulate.c

+52 −23
Original line number Diff line number Diff line
@@ -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),

			rc = segmented_cmpxchg(ctxt,

					       c->dst.addr.mem,

					       &c->dst.orig_val,

					       &c->dst.val,

					c->dst.bytes,

					&ctxt->exception,

					ctxt->vcpu);

					       c->dst.bytes);

		else

			rc = ops->write_emulated(

					linear(ctxt, c->dst.addr.mem),

			rc = segmented_write(ctxt,

					     c->dst.addr.mem,

					     &c->dst.val,

					c->dst.bytes,

					&ctxt->exception,

					ctxt->vcpu);

					     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;
@@ -3440,7 +3469,7 @@ 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),

		rc = segmented_read(ctxt, c->src.addr.mem,

				    c->src.valptr, c->src.bytes);

		if (rc != X86EMUL_CONTINUE)

			goto done;
@@ -3448,7 +3477,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	}



	if (c->src2.type == OP_MEM) {

		rc = read_emulated(ctxt, ops, linear(ctxt, c->src2.addr.mem),

		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;