2016-09-30 2:40 GMT+08:00 Eduardo Habkost <ehabk...@redhat.com>:
> (CCing Richard, sorry I forgot to CC you)
>
> Ping? Any objection to this fix?
>
> On Wed, Sep 28, 2016 at 01:33:15PM -0300, Eduardo Habkost wrote:
>> A regression was introduced by commit 96193c22a "target-i386:
>> Move xsave component mask to features array": all
>> CPUID[EAX=0xD,ECX=0]:EAX bits were being reported as unmigratable
>> because they don't have feature names defined. This broke
>> "-cpu host" because it enables only migratable features by
>> default.
>>
>> This adds a new field to FeatureWordInfo: migratable_flags, which
>> will make those features be reported as migratable even if they
>> don't have a property name defined.
>>
>> Reported-by: Wanpeng Li <wanpeng...@hotmail.com>
>> Cc: Paolo Bonzini <bonz...@gnu.org>
>> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
Reviewed-by: Wanpeng Li <wanpeng...@hotmail.com>
>> ---
>> target-i386/cpu.c | 19 +++++++++++--------
>> 1 file changed, 11 insertions(+), 8 deletions(-)
>>
>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
>> index 333309b..0807e92 100644
>> --- a/target-i386/cpu.c
>> +++ b/target-i386/cpu.c
>> @@ -258,6 +258,7 @@ typedef struct FeatureWordInfo {
>> int cpuid_reg; /* output register (R_* constant) */
>> uint32_t tcg_features; /* Feature flags supported by TCG */
>> uint32_t unmigratable_flags; /* Feature flags known to be unmigratable
>> */
>> + uint32_t migratable_flags; /* Feature flags known to be migratable */
>> } FeatureWordInfo;
>>
>> static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
>> @@ -494,6 +495,10 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS]
>> = {
>> .cpuid_needs_ecx = true, .cpuid_ecx = 0,
>> .cpuid_reg = R_EAX,
>> .tcg_features = ~0U,
>> + .migratable_flags = XSTATE_FP_MASK | XSTATE_SSE_MASK |
>> + XSTATE_YMM_MASK | XSTATE_BNDREGS_MASK | XSTATE_BNDCSR_MASK |
>> + XSTATE_OPMASK_MASK | XSTATE_ZMM_Hi256_MASK |
>> XSTATE_Hi16_ZMM_MASK |
>> + XSTATE_PKRU_MASK,
>> },
>> [FEAT_XSAVE_COMP_HI] = {
>> .cpuid_eax = 0xD,
>> @@ -600,15 +605,13 @@ static uint32_t
>> x86_cpu_get_migratable_flags(FeatureWord w)
>>
>> for (i = 0; i < 32; i++) {
>> uint32_t f = 1U << i;
>> - /* If the feature name is unknown, it is not supported by QEMU yet
>> */
>> - if (!wi->feat_names[i]) {
>> - continue;
>> - }
>> - /* Skip features known to QEMU, but explicitly marked as
>> unmigratable */
>> - if (wi->unmigratable_flags & f) {
>> - continue;
>> +
>> + /* If the feature name is known, it is implicitly considered
>> migratable,
>> + * unless it is explicitly set in unmigratable_flags */
>> + if ((wi->migratable_flags & f) ||
>> + (wi->feat_names[i] && !(wi->unmigratable_flags & f))) {
>> + r |= f;
>> }
>> - r |= f;
>> }
>> return r;
>> }
>> --
>> 2.7.4
>>
>>
>
> --
> Eduardo
