target-i386: Report known CPUID[EAX=0xD,ECX=0]:EAX bits as migratable

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.

Backports commit 6fb2fff75dceed1716e757882a6dfbadd9042407 from qemu
This commit is contained in:
Eduardo Habkost 2018-02-26 04:57:56 -05:00 committed by Lioncash
parent 33589eb75f
commit b7f434373b
No known key found for this signature in database
GPG key ID: 4E3C3CC1031BA9C7

View file

@ -252,6 +252,7 @@ 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] = {
@ -531,6 +532,12 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
true, 0,
R_EAX,
~0U,
0,
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
{
@ -667,15 +674,12 @@ 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;
/* 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;
}
/* Skip features known to QEMU, but explicitly marked as unmigratable */
if (wi->unmigratable_flags & f) {
continue;
}
r |= f;
}
return r;
}