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Commit 79367a65 authored by Paolo Bonzini's avatar Paolo Bonzini
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KVM: x86: introduce linear_{read,write}_system 



Wrap the common invocation of ctxt->ops->read_std and ctxt->ops->write_std, so
as to have a smaller patch when the functions grow another argument.

Fixes: 129a72a0 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 727ba748

arch/x86/kvm/emulate.c

+32 −32
Original line number Diff line number Diff line
@@ -812,6 +812,19 @@ static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) 
	return assign_eip_near(ctxt, ctxt->_eip + rel);

}



static int linear_read_system(struct x86_emulate_ctxt *ctxt, ulong linear,

			      void *data, unsigned size)

{

	return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);

}



static int linear_write_system(struct x86_emulate_ctxt *ctxt,

			       ulong linear, void *data,

			       unsigned int size)

{

	return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception);

}



static int segmented_read_std(struct x86_emulate_ctxt *ctxt,

			      struct segmented_address addr,

			      void *data,
@@ -1496,8 +1509,7 @@ static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt, 
		return emulate_gp(ctxt, index << 3 | 0x2);



	addr = dt.address + index * 8;

	return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,

				   &ctxt->exception);

	return linear_read_system(ctxt, addr, desc, sizeof *desc);

}



static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
@@ -1560,8 +1572,7 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
	if (rc != X86EMUL_CONTINUE)

		return rc;



	return ctxt->ops->read_std(ctxt, *desc_addr_p, desc, sizeof(*desc),

				   &ctxt->exception);

	return linear_read_system(ctxt, *desc_addr_p, desc, sizeof(*desc));

}



/* allowed just for 8 bytes segments */
@@ -1575,8 +1586,7 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
	if (rc != X86EMUL_CONTINUE)

		return rc;



	return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,

				    &ctxt->exception);

	return linear_write_system(ctxt, addr, desc, sizeof *desc);

}



static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
@@ -1737,8 +1747,7 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
				return ret;

		}

	} else if (ctxt->mode == X86EMUL_MODE_PROT64) {

		ret = ctxt->ops->read_std(ctxt, desc_addr+8, &base3,

				sizeof(base3), &ctxt->exception);

		ret = linear_read_system(ctxt, desc_addr+8, &base3, sizeof(base3));

		if (ret != X86EMUL_CONTINUE)

			return ret;

		if (emul_is_noncanonical_address(get_desc_base(&seg_desc) |
@@ -2051,11 +2060,11 @@ static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) 
	eip_addr = dt.address + (irq << 2);

	cs_addr = dt.address + (irq << 2) + 2;



	rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);

	rc = linear_read_system(ctxt, cs_addr, &cs, 2);

	if (rc != X86EMUL_CONTINUE)

		return rc;



	rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);

	rc = linear_read_system(ctxt, eip_addr, &eip, 2);

	if (rc != X86EMUL_CONTINUE)

		return rc;
@@ -3053,35 +3062,30 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt, 
			  u16 tss_selector, u16 old_tss_sel,

			  ulong old_tss_base, struct desc_struct *new_desc)

{

	const struct x86_emulate_ops *ops = ctxt->ops;

	struct tss_segment_16 tss_seg;

	int ret;

	u32 new_tss_base = get_desc_base(new_desc);



	ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,

			    &ctxt->exception);

	ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg);

	if (ret != X86EMUL_CONTINUE)

		return ret;



	save_state_to_tss16(ctxt, &tss_seg);



	ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,

			     &ctxt->exception);

	ret = linear_write_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg);

	if (ret != X86EMUL_CONTINUE)

		return ret;



	ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,

			    &ctxt->exception);

	ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof tss_seg);

	if (ret != X86EMUL_CONTINUE)

		return ret;



	if (old_tss_sel != 0xffff) {

		tss_seg.prev_task_link = old_tss_sel;



		ret = ops->write_std(ctxt, new_tss_base,

		ret = linear_write_system(ctxt, new_tss_base,

					  &tss_seg.prev_task_link,

				     sizeof tss_seg.prev_task_link,

				     &ctxt->exception);

					  sizeof tss_seg.prev_task_link);

		if (ret != X86EMUL_CONTINUE)

			return ret;

	}
@@ -3197,38 +3201,34 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, 
			  u16 tss_selector, u16 old_tss_sel,

			  ulong old_tss_base, struct desc_struct *new_desc)

{

	const struct x86_emulate_ops *ops = ctxt->ops;

	struct tss_segment_32 tss_seg;

	int ret;

	u32 new_tss_base = get_desc_base(new_desc);

	u32 eip_offset = offsetof(struct tss_segment_32, eip);

	u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector);



	ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,

			    &ctxt->exception);

	ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg);

	if (ret != X86EMUL_CONTINUE)

		return ret;



	save_state_to_tss32(ctxt, &tss_seg);



	/* Only GP registers and segment selectors are saved */

	ret = ops->write_std(ctxt, old_tss_base + eip_offset, &tss_seg.eip,

			     ldt_sel_offset - eip_offset, &ctxt->exception);

	ret = linear_write_system(ctxt, old_tss_base + eip_offset, &tss_seg.eip,

				  ldt_sel_offset - eip_offset);

	if (ret != X86EMUL_CONTINUE)

		return ret;



	ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,

			    &ctxt->exception);

	ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof tss_seg);

	if (ret != X86EMUL_CONTINUE)

		return ret;



	if (old_tss_sel != 0xffff) {

		tss_seg.prev_task_link = old_tss_sel;



		ret = ops->write_std(ctxt, new_tss_base,

		ret = linear_write_system(ctxt, new_tss_base,

					  &tss_seg.prev_task_link,

				     sizeof tss_seg.prev_task_link,

				     &ctxt->exception);

					  sizeof tss_seg.prev_task_link);

		if (ret != X86EMUL_CONTINUE)

			return ret;

	}