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Commit e919464b authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: make read_segment_descriptor() return the address 



Some operations want to modify the descriptor later on, so save the
address for future use.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent a14e579f

arch/x86/kvm/emulate.c

+8 −5
Original line number Diff line number Diff line
@@ -1296,7 +1296,8 @@ static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, 


/* allowed just for 8 bytes segments */

static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,

				   u16 selector, struct desc_struct *desc)

				   u16 selector, struct desc_struct *desc,

				   ulong *desc_addr_p)

{

	struct desc_ptr dt;

	u16 index = selector >> 3;
@@ -1307,7 +1308,7 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
	if (dt.size < index * 8 + 7)

		return emulate_gp(ctxt, selector & 0xfffc);



	addr = dt.address + index * 8;

	*desc_addr_p = addr = dt.address + index * 8;

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

				   &ctxt->exception);

}
@@ -1339,6 +1340,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
	unsigned err_vec = GP_VECTOR;

	u32 err_code = 0;

	bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */

	ulong desc_addr;

	int ret;



	memset(&seg_desc, 0, sizeof seg_desc);
@@ -1374,7 +1376,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
	if (null_selector) /* for NULL selector skip all following checks */

		goto load;



	ret = read_segment_descriptor(ctxt, selector, &seg_desc);

	ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr);

	if (ret != X86EMUL_CONTINUE)

		return ret;
@@ -2614,13 +2616,14 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, 
	ulong old_tss_base =

		ops->get_cached_segment_base(ctxt, VCPU_SREG_TR);

	u32 desc_limit;

	ulong desc_addr;



	/* FIXME: old_tss_base == ~0 ? */



	ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc);

	ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr);

	if (ret != X86EMUL_CONTINUE)

		return ret;

	ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);

	ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr);

	if (ret != X86EMUL_CONTINUE)

		return ret;