Commit f58aa483 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Alexander Graf
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spapr_nvram: Enable migration 



The only case when sPAPR NVRAM migrates now is if is backed by a file and
copy-storage migration is performed. In other cases NVRAM does not
migrate regardless whether it is backed by a file or not.

This enables shadow copy of NVRAM in RAM which is read from a file
(if used) and used for reads. Writes to NVRAM are mirrored to the file.

This defines a VMSTATE descriptor for NVRAM device so the memory copy
of NVRAM can migrate and be flushed to a backing file on the destination
if one is specified.

Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 016f7758

hw/nvram/spapr_nvram.c

+64 −17
Original line number Diff line number Diff line
@@ -52,7 +52,6 @@ static void rtas_nvram_fetch(PowerPCCPU *cpu, sPAPREnvironment *spapr, 
{

    sPAPRNVRAM *nvram = spapr->nvram;

    hwaddr offset, buffer, len;

    int alen;

    void *membuf;



    if ((nargs != 3) || (nret != 2)) {
@@ -77,19 +76,14 @@ static void rtas_nvram_fetch(PowerPCCPU *cpu, sPAPREnvironment *spapr, 
        return;

    }



    membuf = cpu_physical_memory_map(buffer, &len, 1);

    if (nvram->blk) {

        alen = blk_pread(nvram->blk, offset, membuf, len);

    } else {

    assert(nvram->buf);



    membuf = cpu_physical_memory_map(buffer, &len, 1);

    memcpy(membuf, nvram->buf + offset, len);

        alen = len;

    }

    cpu_physical_memory_unmap(membuf, len, 1, len);



    rtas_st(rets, 0, (alen < len) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS);

    rtas_st(rets, 1, (alen < 0) ? 0 : alen);

    rtas_st(rets, 0, RTAS_OUT_SUCCESS);

    rtas_st(rets, 1, len);

}



static void rtas_nvram_store(PowerPCCPU *cpu, sPAPREnvironment *spapr,
@@ -123,14 +117,15 @@ static void rtas_nvram_store(PowerPCCPU *cpu, sPAPREnvironment *spapr, 
    }



    membuf = cpu_physical_memory_map(buffer, &len, 0);



    alen = len;

    if (nvram->blk) {

        alen = blk_pwrite(nvram->blk, offset, membuf, len);

    } else {

        assert(nvram->buf);

    }



    assert(nvram->buf);

    memcpy(nvram->buf + offset, membuf, len);

        alen = len;

    }



    cpu_physical_memory_unmap(membuf, len, 0, len);



    rtas_st(rets, 0, (alen < len) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS);
@@ -145,15 +140,24 @@ static int spapr_nvram_init(VIOsPAPRDevice *dev) 
        nvram->size = blk_getlength(nvram->blk);

    } else {

        nvram->size = DEFAULT_NVRAM_SIZE;

        nvram->buf = g_malloc0(nvram->size);

    }



    nvram->buf = g_malloc0(nvram->size);



    if ((nvram->size < MIN_NVRAM_SIZE) || (nvram->size > MAX_NVRAM_SIZE)) {

        fprintf(stderr, "spapr-nvram must be between %d and %d bytes in size\n",

                MIN_NVRAM_SIZE, MAX_NVRAM_SIZE);

        return -1;

    }



    if (nvram->blk) {

        int alen = blk_pread(nvram->blk, 0, nvram->buf, nvram->size);



        if (alen != nvram->size) {

            return -1;

        }

    }



    spapr_rtas_register(RTAS_NVRAM_FETCH, "nvram-fetch", rtas_nvram_fetch);

    spapr_rtas_register(RTAS_NVRAM_STORE, "nvram-store", rtas_nvram_store);
@@ -167,6 +171,48 @@ static int spapr_nvram_devnode(VIOsPAPRDevice *dev, void *fdt, int node_off) 
    return fdt_setprop_cell(fdt, node_off, "#bytes", nvram->size);

}



static int spapr_nvram_pre_load(void *opaque)

{

    sPAPRNVRAM *nvram = VIO_SPAPR_NVRAM(opaque);



    g_free(nvram->buf);

    nvram->buf = NULL;

    nvram->size = 0;



    return 0;

}



static int spapr_nvram_post_load(void *opaque, int version_id)

{

    sPAPRNVRAM *nvram = VIO_SPAPR_NVRAM(opaque);



    if (nvram->blk) {

        int alen = blk_pwrite(nvram->blk, 0, nvram->buf, nvram->size);



        if (alen < 0) {

            return alen;

        }

        if (alen != nvram->size) {

            return -1;

        }

    }



    return 0;

}



static const VMStateDescription vmstate_spapr_nvram = {

    .name = "spapr_nvram",

    .version_id = 1,

    .minimum_version_id = 1,

    .pre_load = spapr_nvram_pre_load,

    .post_load = spapr_nvram_post_load,

    .fields = (VMStateField[]) {

        VMSTATE_UINT32(size, sPAPRNVRAM),

        VMSTATE_VBUFFER_ALLOC_UINT32(buf, sPAPRNVRAM, 1, NULL, 0, size),

        VMSTATE_END_OF_LIST()

    },

};



static Property spapr_nvram_properties[] = {

    DEFINE_SPAPR_PROPERTIES(sPAPRNVRAM, sdev),

    DEFINE_PROP_DRIVE("drive", sPAPRNVRAM, blk),
@@ -185,6 +231,7 @@ static void spapr_nvram_class_init(ObjectClass *klass, void *data) 
    k->dt_compatible = "qemu,spapr-nvram";

    set_bit(DEVICE_CATEGORY_MISC, dc->categories);

    dc->props = spapr_nvram_properties;

    dc->vmsd = &vmstate_spapr_nvram;

}



static const TypeInfo spapr_nvram_type_info = {