Commit 46baa900 authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Eduardo Habkost
Browse files

migration/i386: Remove old non-softfloat 64bit FP support 



Long long ago, we used to support storing the x86 FP registers in
a 64bit format.

Then c31da136 in v0.14-rc0 removed
the last support for writing that in the migration format.
Even before that, it was only used if you had softfloat disabled
 (i.e. !USE_X86LDOUBLE) so in practice use of it in even earlier
qemu is unlikely for most users.

Kill it off, it's complicated, and possibly broken.

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170405190024.27581-2-dgilbert@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent 2941020a

target/i386/machine.c

+6 −101
Original line number Diff line number Diff line
@@ -136,36 +136,6 @@ static const VMStateDescription vmstate_mtrr_var = { 
#define VMSTATE_MTRR_VARS(_field, _state, _n, _v)                    \

    VMSTATE_STRUCT_ARRAY(_field, _state, _n, _v, vmstate_mtrr_var, MTRRVar)



static int put_fpreg_error(QEMUFile *f, void *opaque, size_t size,

                           VMStateField *field, QJSON *vmdesc)

{

    fprintf(stderr, "call put_fpreg() with invalid arguments\n");

    exit(0);

    return 0;

}



/* XXX: add that in a FPU generic layer */

union x86_longdouble {

    uint64_t mant;

    uint16_t exp;

};



#define MANTD1(fp)	(fp & ((1LL << 52) - 1))

#define EXPBIAS1 1023

#define EXPD1(fp)	((fp >> 52) & 0x7FF)

#define SIGND1(fp)	((fp >> 32) & 0x80000000)



static void fp64_to_fp80(union x86_longdouble *p, uint64_t temp)

{

    int e;

    /* mantissa */

    p->mant = (MANTD1(temp) << 11) | (1LL << 63);

    /* exponent + sign */

    e = EXPD1(temp) - EXPBIAS1 + 16383;

    e |= SIGND1(temp) >> 16;

    p->exp = e;

}



static int get_fpreg(QEMUFile *f, void *opaque, size_t size,

                     VMStateField *field)

{
@@ -200,76 +170,6 @@ static const VMStateInfo vmstate_fpreg = { 
    .put  = put_fpreg,

};



static int get_fpreg_1_mmx(QEMUFile *f, void *opaque, size_t size,

                           VMStateField *field)

{

    union x86_longdouble *p = opaque;

    uint64_t mant;



    qemu_get_be64s(f, &mant);

    p->mant = mant;

    p->exp = 0xffff;

    return 0;

}



static const VMStateInfo vmstate_fpreg_1_mmx = {

    .name = "fpreg_1_mmx",

    .get  = get_fpreg_1_mmx,

    .put  = put_fpreg_error,

};



static int get_fpreg_1_no_mmx(QEMUFile *f, void *opaque, size_t size,

                              VMStateField *field)

{

    union x86_longdouble *p = opaque;

    uint64_t mant;



    qemu_get_be64s(f, &mant);

    fp64_to_fp80(p, mant);

    return 0;

}



static const VMStateInfo vmstate_fpreg_1_no_mmx = {

    .name = "fpreg_1_no_mmx",

    .get  = get_fpreg_1_no_mmx,

    .put  = put_fpreg_error,

};



static bool fpregs_is_0(void *opaque, int version_id)

{

    X86CPU *cpu = opaque;

    CPUX86State *env = &cpu->env;



    return (env->fpregs_format_vmstate == 0);

}



static bool fpregs_is_1_mmx(void *opaque, int version_id)

{

    X86CPU *cpu = opaque;

    CPUX86State *env = &cpu->env;

    int guess_mmx;



    guess_mmx = ((env->fptag_vmstate == 0xff) &&

                 (env->fpus_vmstate & 0x3800) == 0);

    return (guess_mmx && (env->fpregs_format_vmstate == 1));

}



static bool fpregs_is_1_no_mmx(void *opaque, int version_id)

{

    X86CPU *cpu = opaque;

    CPUX86State *env = &cpu->env;

    int guess_mmx;



    guess_mmx = ((env->fptag_vmstate == 0xff) &&

                 (env->fpus_vmstate & 0x3800) == 0);

    return (!guess_mmx && (env->fpregs_format_vmstate == 1));

}



#define VMSTATE_FP_REGS(_field, _state, _n)                               \

    VMSTATE_ARRAY_TEST(_field, _state, _n, fpregs_is_0, vmstate_fpreg, FPReg), \

    VMSTATE_ARRAY_TEST(_field, _state, _n, fpregs_is_1_mmx, vmstate_fpreg_1_mmx, FPReg), \

    VMSTATE_ARRAY_TEST(_field, _state, _n, fpregs_is_1_no_mmx, vmstate_fpreg_1_no_mmx, FPReg)



static bool version_is_5(void *opaque, int version_id)

{

    return version_id == 5;
@@ -356,6 +256,10 @@ static int cpu_post_load(void *opaque, int version_id) 
        return -EINVAL;

    }



    if (env->fpregs_format_vmstate) {

        error_report("Unsupported old non-softfloat CPU state");

        return -EINVAL;

    }

    /*

     * Real mode guest segments register DPL should be zero.

     * Older KVM version were setting it wrongly.
@@ -943,7 +847,8 @@ VMStateDescription vmstate_x86_cpu = { 
        VMSTATE_UINT16(env.fpus_vmstate, X86CPU),

        VMSTATE_UINT16(env.fptag_vmstate, X86CPU),

        VMSTATE_UINT16(env.fpregs_format_vmstate, X86CPU),

        VMSTATE_FP_REGS(env.fpregs, X86CPU, 8),



        VMSTATE_STRUCT_ARRAY(env.fpregs, X86CPU, 8, 0, vmstate_fpreg, FPReg),



        VMSTATE_SEGMENT_ARRAY(env.segs, X86CPU, 6),

        VMSTATE_SEGMENT(env.ldt, X86CPU),