]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
KVM: x86 emulator: fix eflags preparation for emulation
authorAvi Kivity <avi@qumranet.com>
Thu, 6 Dec 2007 14:15:02 +0000 (16:15 +0200)
committerAvi Kivity <avi@qumranet.com>
Wed, 30 Jan 2008 15:53:19 +0000 (17:53 +0200)
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 <avi@qumranet.com>
drivers/kvm/x86_emulate.c

index 2e259a847697a1b116fdfdfbc9958bad585d7df3..f423b0e327f44c820ade44c66566bfe3921cdcb3 100644 (file)
@@ -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) \