# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1250693891 -3600
# Node ID bea861fb0f20671d41e467557bfdffb67b42f5e7
# Parent aa9f0b39c021f9c6e2c5cdb225564dd554a727f5
x86_emulate: Emulate LLDT and LTR instructions.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
xen-unstable changeset: 19614:e421fd04e150
xen-unstable date: Tue May 19 02:09:36 2009 +0100
---
xen/arch/x86/x86_emulate/x86_emulate.c | 35 +++++++++++++++++++++++----------
1 files changed, 25 insertions(+), 10 deletions(-)
diff -r aa9f0b39c021 -r bea861fb0f20 xen/arch/x86/x86_emulate/x86_emulate.c
--- a/xen/arch/x86/x86_emulate/x86_emulate.c Wed Aug 19 15:57:36 2009 +0100
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c Wed Aug 19 15:58:11 2009 +0100
@@ -172,7 +172,7 @@ static uint8_t opcode_table[256] = {
static uint8_t twobyte_table[256] = {
/* 0x00 - 0x07 */
- 0, ImplicitOps|ModRM, 0, 0, 0, 0, ImplicitOps, 0,
+ SrcMem16|ModRM, ImplicitOps|ModRM, 0, 0, 0, 0, ImplicitOps, 0,
/* 0x08 - 0x0F */
ImplicitOps, ImplicitOps, 0, 0, 0, ImplicitOps|ModRM, 0, 0,
/* 0x10 - 0x17 */
@@ -971,8 +971,8 @@ protmode_load_seg(
struct { uint32_t a, b; } desc;
unsigned long val;
uint8_t dpl, rpl, cpl;
- uint32_t new_desc_b;
- int rc, fault_type = EXC_TS;
+ uint32_t new_desc_b, a_flag = 0x100;
+ int rc, fault_type = EXC_GP;
/* NULL selector? */
if ( (sel & 0xfffc) == 0 )
@@ -983,8 +983,8 @@ protmode_load_seg(
return ops->write_segment(seg, &segr, ctxt);
}
- /* LDT descriptor must be in the GDT. */
- if ( (seg == x86_seg_ldtr) && (sel & 4) )
+ /* System segment descriptors must reside in the GDT. */
+ if ( !is_x86_user_segment(seg) && (sel & 4) )
goto raise_exn;
if ( (rc = ops->read_segment(x86_seg_ss, &ss, ctxt)) ||
@@ -1013,8 +1013,8 @@ protmode_load_seg(
goto raise_exn;
}
- /* LDT descriptor is a system segment. All others are code/data. */
- if ( (desc.b & (1u<<12)) == ((seg == x86_seg_ldtr) << 12) )
+ /* System segments must have the system flag (S) set. */
+ if ( (desc.b & (1u<<12)) == (!is_x86_user_segment(seg) << 12) )
goto raise_exn;
dpl = (desc.b >> 13) & 3;
@@ -1043,6 +1043,12 @@ protmode_load_seg(
if ( (desc.b & (15u<<8)) != (2u<<8) )
goto raise_exn;
goto skip_accessed_flag;
+ case x86_seg_tr:
+ /* Available TSS system segment? */
+ if ( (desc.b & (15u<<8)) != (9u<<8) )
+ goto raise_exn;
+ a_flag = 0x200; /* busy flag */
+ break;
default:
/* Readable code or data segment? */
if ( (desc.b & (5u<<9)) == (4u<<9) )
@@ -1055,8 +1061,8 @@ protmode_load_seg(
}
/* Ensure Accessed flag is set. */
- new_desc_b = desc.b | 0x100;
- rc = ((desc.b & 0x100) ? X86EMUL_OKAY :
+ new_desc_b = desc.b | a_flag;
+ rc = ((desc.b & a_flag) ? X86EMUL_OKAY :
ops->cmpxchg(
x86_seg_none, desctab.base + (sel & 0xfff8) + 4,
&desc.b, &new_desc_b, 4, ctxt));
@@ -1066,7 +1072,7 @@ protmode_load_seg(
return rc;
/* Force the Accessed flag in our local copy. */
- desc.b |= 0x100;
+ desc.b |= a_flag;
skip_accessed_flag:
segr.base = (((desc.b << 0) & 0xff000000u) |
@@ -3440,6 +3446,15 @@ x86_emulate(
twobyte_insn:
switch ( b )
{
+ case 0x00: /* Grp6 */
+ fail_if((modrm_reg & 6) != 2);
+ generate_exception_if(!in_protmode(ctxt, ops), EXC_UD, -1);
+ generate_exception_if(!mode_ring0(), EXC_GP, 0);
+ if ( (rc = load_seg((modrm_reg & 1) ? x86_seg_tr : x86_seg_ldtr,
+ src.val, ctxt, ops)) != 0 )
+ goto done;
+ break;
+
case 0x01: /* Grp7 */ {
struct segment_register reg;
unsigned long base, limit, cr0, cr0w;
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