Commit 6fb2fff7 authored by Eduardo Habkost's avatar Eduardo Habkost
Browse files

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



A regression was introduced by commit 96193c22 "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: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Cc: Paolo Bonzini <bonzini@gnu.org>
Reviewed-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent c5d128ff

target-i386/cpu.c

+11 −8
Original line number Diff line number Diff line
@@ -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,
@@ -600,16 +605,14 @@ 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;

        }

    }

    return r;

}