We prepare eflags for the emulated instruction, then clobber it with an 'andl'.
Fix by popping eflags as the last thing in the sequence.

Patch taken from Xen (16143:959b4b92b6bf)

Signed-off-by: Avi Kivity <[EMAIL PROTECTED]>
---
 drivers/kvm/x86_emulate.c |   30 +++++++++++++++---------------
 1 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 2e259a8..f423b0e 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -256,21 +256,21 @@ static u16 twobyte_table[256] = {
 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
 
 /* Before executing instruction: restore necessary bits in EFLAGS. */
-#define _PRE_EFLAGS(_sav, _msk, _tmp) \
-       /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); */        \
-       "push %"_sav"; "                                        \
-       "movl %"_msk",%"_LO32 _tmp"; "                          \
-       "andl %"_LO32 _tmp",("_STK"); "                         \
-       "pushf; "                                               \
-       "notl %"_LO32 _tmp"; "                                  \
-       "andl %"_LO32 _tmp",("_STK"); "                         \
-       "pop  %"_tmp"; "                                        \
-       "orl  %"_LO32 _tmp",("_STK"); "                         \
-       "popf; "                                                \
-       /* _sav &= ~msk; */                                     \
-       "movl %"_msk",%"_LO32 _tmp"; "                          \
-       "notl %"_LO32 _tmp"; "                                  \
-       "andl %"_LO32 _tmp",%"_sav"; "
+#define _PRE_EFLAGS(_sav, _msk, _tmp)                                  \
+       /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \
+       "movl %"_sav",%"_LO32 _tmp"; "                                  \
+       "push %"_tmp"; "                                                \
+       "push %"_tmp"; "                                                \
+       "movl %"_msk",%"_LO32 _tmp"; "                                  \
+       "andl %"_LO32 _tmp",("_STK"); "                                 \
+       "pushf; "                                                       \
+       "notl %"_LO32 _tmp"; "                                          \
+       "andl %"_LO32 _tmp",("_STK"); "                                 \
+       "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); "   \
+       "pop  %"_tmp"; "                                                \
+       "orl  %"_LO32 _tmp",("_STK"); "                                 \
+       "popf; "                                                        \
+       "pop  %"_sav"; "
 
 /* After executing instruction: write-back necessary bits in EFLAGS. */
 #define _POST_EFLAGS(_sav, _msk, _tmp) \
-- 
1.5.3.7


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