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: Alexey Kardashevskiy <a...@ozlabs.ru>
---
Changes:
v2:
* implemented full-time shadow copy of NVRAM which is read from a file
at start and stays in RAM during live of the guest
---
hw/nvram/spapr_nvram.c | 81 ++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 65 insertions(+), 16 deletions(-)
diff --git a/hw/nvram/spapr_nvram.c b/hw/nvram/spapr_nvram.c
index 6a72ef4..d34edfb 100644
--- a/hw/nvram/spapr_nvram.c
+++ b/hw/nvram/spapr_nvram.c
@@ -51,7 +51,6 @@ 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)) {
@@ -76,19 +75,16 @@ static void rtas_nvram_fetch(PowerPCCPU *cpu,
sPAPREnvironment *spapr,
return;
}
+ assert(nvram->buf);
+
membuf = cpu_physical_memory_map(buffer, &len, 1);
- if (nvram->drive) {
- alen = bdrv_pread(nvram->drive, offset, membuf, len);
- } else {
- assert(nvram->buf);
- memcpy(membuf, nvram->buf + offset, len);
- alen = len;
- }
+ memcpy(membuf, nvram->buf + offset, 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,
@@ -122,14 +118,15 @@ 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);
@@ -144,15 +141,24 @@ 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);
return -1;
}
+ if (nvram->drive) {
+ int alen = bdrv_pread(nvram->drive, 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);
@@ -166,6 +172,48 @@ 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);
+
+ 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 +232,7 @@ 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 = {
--
2.0.0
