[PATCH 3/4] Fix x86 feature modifications for features that set multiple bits

Avi Kivity
2009-05-03T14:04:13Z

QEMU allows adding or removing cpu features by using the syntax '-cpu +feature'
or '-cpu -feature'. Some cpuid features cause more than one bit to be set or
cleared; but QEMU stops after just one bit has been modified, causing the
feature bits to be inconsistent.

Fix by allowing all feature bits corresponding to a given name to be set.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
target-i386/helper.c | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/target-i386/helper.c b/target-i386/helper.c
index 88585b8..0c91133 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -66,28 +66,31 @@ static void add_flagname_to_bitmaps(char *flagname, uint32_t *features,
uint32_t *ext3_features)
{
int i;
+ int found = 0;

for ( i = 0 ; i < 32 ; i++ )
if (feature_name[i] && !strcmp (flagname, feature_name[i])) {
*features |= 1 << i;
- return;
+ found = 1;
}
for ( i = 0 ; i < 32 ; i++ )
if (ext_feature_name[i] && !strcmp (flagname, ext_feature_name[i])) {
*ext_features |= 1 << i;
- return;
+ found = 1;
}
for ( i = 0 ; i < 32 ; i++ )
if (ext2_feature_name[i] && !strcmp (flagname, ext2_feature_name[i])) {
*ext2_features |= 1 << i;
- return;
+ found = 1;
}
for ( i = 0 ; i < 32 ; i++ )
if (ext3_feature_name[i] && !strcmp (flagname, ext3_feature_name[i])) {
*ext3_features |= 1 << i;
- return;
+ found = 1;
}
- fprintf(stderr, "CPU feature %s not found\n", flagname);
+ if (!found) {
+ fprintf(stderr, "CPU feature %s not found\n", flagname);
+ }
}

typedef struct x86_def_t {
--
1.6.1.1