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forked from pool/xen
xen/24275-x86-emul-lzcnt.patch
Charles Arnold 3f55414718 - Update to Xen 4.1.3 c/s 23336
- Upstream or pending upstream patches from Jan
  25587-fix-off-by-one-parsing-error.patch
  25616-x86-MCi_CTL-default.patch
  25617-vtd-qinval-addr.patch
  25688-x86-nr_irqs_gsi.patch
- bnc#773393 - VUL-0: CVE-2012-3433: xen: HVM guest destroy p2m
  teardown host DoS vulnerability
  CVE-2012-3433-xsa11.patch
- bnc#773401 - VUL-1: CVE-2012-3432: xen: HVM guest user mode MMIO
  emulation DoS
  25682-x86-inconsistent-io-state.patch

- bnc#762484 - VUL-1: CVE-2012-2625: xen: pv bootloader doesn't
  check the size of the bzip2 or lzma compressed kernel, leading to
  denial of service
  25589-pygrub-size-limits.patch

- Make it build with latest TeXLive 2012 with new package layout

OBS-URL: https://build.opensuse.org/package/show/Virtualization/xen?expand=0&rev=196
2012-08-10 21:38:41 +00:00

91 lines
2.9 KiB
Diff

# HG changeset patch
# User Jan Beulich <jbeulich@suse.com>
# Date 1322725849 -3600
# Node ID 76ea126f21724b72c120aff59460f7bbe9e6960d
# Parent 07cf778d517fdf661a34027af653a489489bf222
x86/emulator: properly handle lzcnt and tzcnt
These instructions are prefix selected flavors of bsf and bsr
respectively, and hence the presences of the F3 prefix must be handled
in the emulation code in order to avoid running into problems on newer
CPUs.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Index: xen-4.1.3-testing/xen/arch/x86/x86_emulate/x86_emulate.c
===================================================================
--- xen-4.1.3-testing.orig/xen/arch/x86/x86_emulate/x86_emulate.c
+++ xen-4.1.3-testing/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -990,6 +990,9 @@ static bool_t vcpu_has(
return rc == X86EMUL_OKAY;
}
+#define vcpu_has_lzcnt() vcpu_has(0x80000001, ECX, 5, ctxt, ops)
+#define vcpu_has_bmi1() vcpu_has(0x00000007, EBX, 3, ctxt, ops)
+
#define vcpu_must_have(leaf, reg, bit) \
generate_exception_if(!vcpu_has(leaf, reg, bit, ctxt, ops), EXC_UD, -1)
#define vcpu_must_have_sse2() vcpu_must_have(0x00000001, EDX, 26)
@@ -4117,13 +4120,24 @@ x86_emulate(
dst.val = (uint8_t)src.val;
break;
- case 0xbc: /* bsf */ {
- int zf;
+ case 0xbc: /* bsf or tzcnt */ {
+ bool_t zf;
asm ( "bsf %2,%0; setz %b1"
: "=r" (dst.val), "=q" (zf)
- : "r" (src.val), "1" (0) );
+ : "r" (src.val) );
_regs.eflags &= ~EFLG_ZF;
- if ( zf )
+ if ( (rep_prefix == REPE_PREFIX) && vcpu_has_bmi1() )
+ {
+ _regs.eflags &= ~EFLG_CF;
+ if ( zf )
+ {
+ _regs.eflags |= EFLG_CF;
+ dst.val = op_bytes * 8;
+ }
+ else if ( !dst.val )
+ _regs.eflags |= EFLG_ZF;
+ }
+ else if ( zf )
{
_regs.eflags |= EFLG_ZF;
dst.type = OP_NONE;
@@ -4131,13 +4145,28 @@ x86_emulate(
break;
}
- case 0xbd: /* bsr */ {
- int zf;
+ case 0xbd: /* bsr or lzcnt */ {
+ bool_t zf;
asm ( "bsr %2,%0; setz %b1"
: "=r" (dst.val), "=q" (zf)
- : "r" (src.val), "1" (0) );
+ : "r" (src.val) );
_regs.eflags &= ~EFLG_ZF;
- if ( zf )
+ if ( (rep_prefix == REPE_PREFIX) && vcpu_has_lzcnt() )
+ {
+ _regs.eflags &= ~EFLG_CF;
+ if ( zf )
+ {
+ _regs.eflags |= EFLG_CF;
+ dst.val = op_bytes * 8;
+ }
+ else
+ {
+ dst.val = op_bytes * 8 - 1 - dst.val;
+ if ( !dst.val )
+ _regs.eflags |= EFLG_ZF;
+ }
+ }
+ else if ( zf )
{
_regs.eflags |= EFLG_ZF;
dst.type = OP_NONE;