On 25.09.14 09:02, Alexey Kardashevskiy wrote:
> The only case when sPAPR NVRAM migrates now is if is backed by a file and
> copy-storage migration is performed.
>
> This enables RAM copy of NVRAM even if NVRAM is backed by a file.
>
> This defines a VMSTATE descriptor for NVRAM device so the memory copy
> of NVRAM can migrate and be written to a backing file on the destination
> if one is provided.
>
> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> ---
> hw/nvram/spapr_nvram.c | 68
> +++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 59 insertions(+), 9 deletions(-)
>
> diff --git a/hw/nvram/spapr_nvram.c b/hw/nvram/spapr_nvram.c
> index 6a72ef4..254009e 100644
> --- a/hw/nvram/spapr_nvram.c
> +++ b/hw/nvram/spapr_nvram.c
> @@ -76,15 +76,20 @@ static void rtas_nvram_fetch(PowerPCCPU *cpu,
> sPAPREnvironment *spapr,
> return;
> }
>
> + assert(nvram->buf);
> +
> membuf = cpu_physical_memory_map(buffer, &len, 1);
> +
> + alen = len;
> if (nvram->drive) {
> alen = bdrv_pread(nvram->drive, offset, membuf, len);
> + if (alen > 0) {
> + memcpy(nvram->buf + offset, membuf, alen);
Why?
> + }
> } else {
> - assert(nvram->buf);
> -
> 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);
> @@ -122,14 +127,15 @@ static void rtas_nvram_store(PowerPCCPU *cpu,
> sPAPREnvironment *spapr,
> }
>
> membuf = cpu_physical_memory_map(buffer, &len, 0);
> +
> + alen = len;
> if (nvram->drive) {
> alen = bdrv_pwrite(nvram->drive, offset, membuf, len);
> - } else {
> - assert(nvram->buf);
> -
> - memcpy(nvram->buf + offset, membuf, len);
> - alen = len;
> }
> +
> + assert(nvram->buf);
> + memcpy(nvram->buf + offset, membuf, len);
> +
> cpu_physical_memory_unmap(membuf, len, 0, len);
>
> rtas_st(rets, 0, (alen < len) ? RTAS_OUT_HW_ERROR : RTAS_OUT_SUCCESS);
> @@ -144,9 +150,10 @@ static int spapr_nvram_init(VIOsPAPRDevice *dev)
> nvram->size = bdrv_getlength(nvram->drive);
> } 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);
> @@ -166,6 +173,48 @@ 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->drive) {
> + int alen = bdrv_pwrite(nvram->drive, 0, nvram->buf, nvram->size);
In the file backed case you're already overwriting the disk backed
version, no?
Also, couldn't you just do the copy and provisioning of buf in a
pre_save hook?
Alex
> +
> + 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, drive),
> @@ -184,6 +233,7 @@ 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 = {
>
