qemu/migration/vmstate.c
Dr. David Alan Gilbert 7c1e52ba6f Move copy out of qemu_peek_buffer
qemu_peek_buffer currently copies the data it reads into a buffer,
however a future patch wants access to the buffer without the copy,
hence rework to remove the copy to the layer above.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-06-12 06:54:01 +02:00

880 lines
22 KiB
C

#include "qemu-common.h"
#include "migration/migration.h"
#include "migration/qemu-file.h"
#include "migration/vmstate.h"
#include "qemu/bitops.h"
#include "qemu/error-report.h"
#include "trace.h"
#include "qjson.h"
static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque, QJSON *vmdesc);
static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque);
static int vmstate_n_elems(void *opaque, VMStateField *field)
{
int n_elems = 1;
if (field->flags & VMS_ARRAY) {
n_elems = field->num;
} else if (field->flags & VMS_VARRAY_INT32) {
n_elems = *(int32_t *)(opaque+field->num_offset);
} else if (field->flags & VMS_VARRAY_UINT32) {
n_elems = *(uint32_t *)(opaque+field->num_offset);
} else if (field->flags & VMS_VARRAY_UINT16) {
n_elems = *(uint16_t *)(opaque+field->num_offset);
} else if (field->flags & VMS_VARRAY_UINT8) {
n_elems = *(uint8_t *)(opaque+field->num_offset);
}
return n_elems;
}
static int vmstate_size(void *opaque, VMStateField *field)
{
int size = field->size;
if (field->flags & VMS_VBUFFER) {
size = *(int32_t *)(opaque+field->size_offset);
if (field->flags & VMS_MULTIPLY) {
size *= field->size;
}
}
return size;
}
static void *vmstate_base_addr(void *opaque, VMStateField *field, bool alloc)
{
void *base_addr = opaque + field->offset;
if (field->flags & VMS_POINTER) {
if (alloc && (field->flags & VMS_ALLOC)) {
gsize size = 0;
if (field->flags & VMS_VBUFFER) {
size = vmstate_size(opaque, field);
} else {
int n_elems = vmstate_n_elems(opaque, field);
if (n_elems) {
size = n_elems * field->size;
}
}
if (size) {
*((void **)base_addr + field->start) = g_malloc(size);
}
}
base_addr = *(void **)base_addr + field->start;
}
return base_addr;
}
int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque, int version_id)
{
VMStateField *field = vmsd->fields;
int ret = 0;
trace_vmstate_load_state(vmsd->name, version_id);
if (version_id > vmsd->version_id) {
trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL);
return -EINVAL;
}
if (version_id < vmsd->minimum_version_id) {
if (vmsd->load_state_old &&
version_id >= vmsd->minimum_version_id_old) {
ret = vmsd->load_state_old(f, opaque, version_id);
trace_vmstate_load_state_end(vmsd->name, "old path", ret);
return ret;
}
trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL);
return -EINVAL;
}
if (vmsd->pre_load) {
int ret = vmsd->pre_load(opaque);
if (ret) {
return ret;
}
}
while (field->name) {
trace_vmstate_load_state_field(vmsd->name, field->name);
if ((field->field_exists &&
field->field_exists(opaque, version_id)) ||
(!field->field_exists &&
field->version_id <= version_id)) {
void *base_addr = vmstate_base_addr(opaque, field, true);
int i, n_elems = vmstate_n_elems(opaque, field);
int size = vmstate_size(opaque, field);
for (i = 0; i < n_elems; i++) {
void *addr = base_addr + size * i;
if (field->flags & VMS_ARRAY_OF_POINTER) {
addr = *(void **)addr;
}
if (field->flags & VMS_STRUCT) {
ret = vmstate_load_state(f, field->vmsd, addr,
field->vmsd->version_id);
} else {
ret = field->info->get(f, addr, size);
}
if (ret >= 0) {
ret = qemu_file_get_error(f);
}
if (ret < 0) {
qemu_file_set_error(f, ret);
trace_vmstate_load_field_error(field->name, ret);
return ret;
}
}
} else if (field->flags & VMS_MUST_EXIST) {
error_report("Input validation failed: %s/%s",
vmsd->name, field->name);
return -1;
}
field++;
}
ret = vmstate_subsection_load(f, vmsd, opaque);
if (ret != 0) {
return ret;
}
if (vmsd->post_load) {
ret = vmsd->post_load(opaque, version_id);
}
trace_vmstate_load_state_end(vmsd->name, "end", ret);
return ret;
}
static int vmfield_name_num(VMStateField *start, VMStateField *search)
{
VMStateField *field;
int found = 0;
for (field = start; field->name; field++) {
if (!strcmp(field->name, search->name)) {
if (field == search) {
return found;
}
found++;
}
}
return -1;
}
static bool vmfield_name_is_unique(VMStateField *start, VMStateField *search)
{
VMStateField *field;
int found = 0;
for (field = start; field->name; field++) {
if (!strcmp(field->name, search->name)) {
found++;
/* name found more than once, so it's not unique */
if (found > 1) {
return false;
}
}
}
return true;
}
static const char *vmfield_get_type_name(VMStateField *field)
{
const char *type = "unknown";
if (field->flags & VMS_STRUCT) {
type = "struct";
} else if (field->info->name) {
type = field->info->name;
}
return type;
}
static bool vmsd_can_compress(VMStateField *field)
{
if (field->field_exists) {
/* Dynamically existing fields mess up compression */
return false;
}
if (field->flags & VMS_STRUCT) {
VMStateField *sfield = field->vmsd->fields;
while (sfield->name) {
if (!vmsd_can_compress(sfield)) {
/* Child elements can't compress, so can't we */
return false;
}
sfield++;
}
if (field->vmsd->subsections) {
/* Subsections may come and go, better don't compress */
return false;
}
}
return true;
}
static void vmsd_desc_field_start(const VMStateDescription *vmsd, QJSON *vmdesc,
VMStateField *field, int i, int max)
{
char *name, *old_name;
bool is_array = max > 1;
bool can_compress = vmsd_can_compress(field);
if (!vmdesc) {
return;
}
name = g_strdup(field->name);
/* Field name is not unique, need to make it unique */
if (!vmfield_name_is_unique(vmsd->fields, field)) {
int num = vmfield_name_num(vmsd->fields, field);
old_name = name;
name = g_strdup_printf("%s[%d]", name, num);
g_free(old_name);
}
json_start_object(vmdesc, NULL);
json_prop_str(vmdesc, "name", name);
if (is_array) {
if (can_compress) {
json_prop_int(vmdesc, "array_len", max);
} else {
json_prop_int(vmdesc, "index", i);
}
}
json_prop_str(vmdesc, "type", vmfield_get_type_name(field));
if (field->flags & VMS_STRUCT) {
json_start_object(vmdesc, "struct");
}
g_free(name);
}
static void vmsd_desc_field_end(const VMStateDescription *vmsd, QJSON *vmdesc,
VMStateField *field, size_t size, int i)
{
if (!vmdesc) {
return;
}
if (field->flags & VMS_STRUCT) {
/* We printed a struct in between, close its child object */
json_end_object(vmdesc);
}
json_prop_int(vmdesc, "size", size);
json_end_object(vmdesc);
}
void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque, QJSON *vmdesc)
{
VMStateField *field = vmsd->fields;
if (vmsd->pre_save) {
vmsd->pre_save(opaque);
}
if (vmdesc) {
json_prop_str(vmdesc, "vmsd_name", vmsd->name);
json_prop_int(vmdesc, "version", vmsd->version_id);
json_start_array(vmdesc, "fields");
}
while (field->name) {
if (!field->field_exists ||
field->field_exists(opaque, vmsd->version_id)) {
void *base_addr = vmstate_base_addr(opaque, field, false);
int i, n_elems = vmstate_n_elems(opaque, field);
int size = vmstate_size(opaque, field);
int64_t old_offset, written_bytes;
QJSON *vmdesc_loop = vmdesc;
for (i = 0; i < n_elems; i++) {
void *addr = base_addr + size * i;
vmsd_desc_field_start(vmsd, vmdesc_loop, field, i, n_elems);
old_offset = qemu_ftell_fast(f);
if (field->flags & VMS_ARRAY_OF_POINTER) {
addr = *(void **)addr;
}
if (field->flags & VMS_STRUCT) {
vmstate_save_state(f, field->vmsd, addr, vmdesc_loop);
} else {
field->info->put(f, addr, size);
}
written_bytes = qemu_ftell_fast(f) - old_offset;
vmsd_desc_field_end(vmsd, vmdesc_loop, field, written_bytes, i);
/* Compressed arrays only care about the first element */
if (vmdesc_loop && vmsd_can_compress(field)) {
vmdesc_loop = NULL;
}
}
} else {
if (field->flags & VMS_MUST_EXIST) {
error_report("Output state validation failed: %s/%s",
vmsd->name, field->name);
assert(!(field->flags & VMS_MUST_EXIST));
}
}
field++;
}
if (vmdesc) {
json_end_array(vmdesc);
}
vmstate_subsection_save(f, vmsd, opaque, vmdesc);
}
static const VMStateDescription *
vmstate_get_subsection(const VMStateDescription **sub, char *idstr)
{
while (sub && *sub && (*sub)->needed) {
if (strcmp(idstr, (*sub)->name) == 0) {
return *sub;
}
sub++;
}
return NULL;
}
static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque)
{
trace_vmstate_subsection_load(vmsd->name);
while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) {
char idstr[256], *idstr_ret;
int ret;
uint8_t version_id, len, size;
const VMStateDescription *sub_vmsd;
len = qemu_peek_byte(f, 1);
if (len < strlen(vmsd->name) + 1) {
/* subsection name has be be "section_name/a" */
trace_vmstate_subsection_load_bad(vmsd->name, "(short)");
return 0;
}
size = qemu_peek_buffer(f, (uint8_t **)&idstr_ret, len, 2);
if (size != len) {
trace_vmstate_subsection_load_bad(vmsd->name, "(peek fail)");
return 0;
}
memcpy(idstr, idstr_ret, size);
idstr[size] = 0;
if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) {
trace_vmstate_subsection_load_bad(vmsd->name, idstr);
/* it don't have a valid subsection name */
return 0;
}
sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr);
if (sub_vmsd == NULL) {
trace_vmstate_subsection_load_bad(vmsd->name, "(lookup)");
return -ENOENT;
}
qemu_file_skip(f, 1); /* subsection */
qemu_file_skip(f, 1); /* len */
qemu_file_skip(f, len); /* idstr */
version_id = qemu_get_be32(f);
ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
if (ret) {
trace_vmstate_subsection_load_bad(vmsd->name, "(child)");
return ret;
}
}
trace_vmstate_subsection_load_good(vmsd->name);
return 0;
}
static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
void *opaque, QJSON *vmdesc)
{
const VMStateDescription **sub = vmsd->subsections;
bool subsection_found = false;
while (sub && *sub && (*sub)->needed) {
if ((*sub)->needed(opaque)) {
const VMStateDescription *vmsd = *sub;
uint8_t len;
if (vmdesc) {
/* Only create subsection array when we have any */
if (!subsection_found) {
json_start_array(vmdesc, "subsections");
subsection_found = true;
}
json_start_object(vmdesc, NULL);
}
qemu_put_byte(f, QEMU_VM_SUBSECTION);
len = strlen(vmsd->name);
qemu_put_byte(f, len);
qemu_put_buffer(f, (uint8_t *)vmsd->name, len);
qemu_put_be32(f, vmsd->version_id);
vmstate_save_state(f, vmsd, opaque, vmdesc);
if (vmdesc) {
json_end_object(vmdesc);
}
}
sub++;
}
if (vmdesc && subsection_found) {
json_end_array(vmdesc);
}
}
/* bool */
static int get_bool(QEMUFile *f, void *pv, size_t size)
{
bool *v = pv;
*v = qemu_get_byte(f);
return 0;
}
static void put_bool(QEMUFile *f, void *pv, size_t size)
{
bool *v = pv;
qemu_put_byte(f, *v);
}
const VMStateInfo vmstate_info_bool = {
.name = "bool",
.get = get_bool,
.put = put_bool,
};
/* 8 bit int */
static int get_int8(QEMUFile *f, void *pv, size_t size)
{
int8_t *v = pv;
qemu_get_s8s(f, v);
return 0;
}
static void put_int8(QEMUFile *f, void *pv, size_t size)
{
int8_t *v = pv;
qemu_put_s8s(f, v);
}
const VMStateInfo vmstate_info_int8 = {
.name = "int8",
.get = get_int8,
.put = put_int8,
};
/* 16 bit int */
static int get_int16(QEMUFile *f, void *pv, size_t size)
{
int16_t *v = pv;
qemu_get_sbe16s(f, v);
return 0;
}
static void put_int16(QEMUFile *f, void *pv, size_t size)
{
int16_t *v = pv;
qemu_put_sbe16s(f, v);
}
const VMStateInfo vmstate_info_int16 = {
.name = "int16",
.get = get_int16,
.put = put_int16,
};
/* 32 bit int */
static int get_int32(QEMUFile *f, void *pv, size_t size)
{
int32_t *v = pv;
qemu_get_sbe32s(f, v);
return 0;
}
static void put_int32(QEMUFile *f, void *pv, size_t size)
{
int32_t *v = pv;
qemu_put_sbe32s(f, v);
}
const VMStateInfo vmstate_info_int32 = {
.name = "int32",
.get = get_int32,
.put = put_int32,
};
/* 32 bit int. See that the received value is the same than the one
in the field */
static int get_int32_equal(QEMUFile *f, void *pv, size_t size)
{
int32_t *v = pv;
int32_t v2;
qemu_get_sbe32s(f, &v2);
if (*v == v2) {
return 0;
}
return -EINVAL;
}
const VMStateInfo vmstate_info_int32_equal = {
.name = "int32 equal",
.get = get_int32_equal,
.put = put_int32,
};
/* 32 bit int. Check that the received value is non-negative
* and less than or equal to the one in the field.
*/
static int get_int32_le(QEMUFile *f, void *pv, size_t size)
{
int32_t *cur = pv;
int32_t loaded;
qemu_get_sbe32s(f, &loaded);
if (loaded >= 0 && loaded <= *cur) {
*cur = loaded;
return 0;
}
return -EINVAL;
}
const VMStateInfo vmstate_info_int32_le = {
.name = "int32 le",
.get = get_int32_le,
.put = put_int32,
};
/* 64 bit int */
static int get_int64(QEMUFile *f, void *pv, size_t size)
{
int64_t *v = pv;
qemu_get_sbe64s(f, v);
return 0;
}
static void put_int64(QEMUFile *f, void *pv, size_t size)
{
int64_t *v = pv;
qemu_put_sbe64s(f, v);
}
const VMStateInfo vmstate_info_int64 = {
.name = "int64",
.get = get_int64,
.put = put_int64,
};
/* 8 bit unsigned int */
static int get_uint8(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_get_8s(f, v);
return 0;
}
static void put_uint8(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_put_8s(f, v);
}
const VMStateInfo vmstate_info_uint8 = {
.name = "uint8",
.get = get_uint8,
.put = put_uint8,
};
/* 16 bit unsigned int */
static int get_uint16(QEMUFile *f, void *pv, size_t size)
{
uint16_t *v = pv;
qemu_get_be16s(f, v);
return 0;
}
static void put_uint16(QEMUFile *f, void *pv, size_t size)
{
uint16_t *v = pv;
qemu_put_be16s(f, v);
}
const VMStateInfo vmstate_info_uint16 = {
.name = "uint16",
.get = get_uint16,
.put = put_uint16,
};
/* 32 bit unsigned int */
static int get_uint32(QEMUFile *f, void *pv, size_t size)
{
uint32_t *v = pv;
qemu_get_be32s(f, v);
return 0;
}
static void put_uint32(QEMUFile *f, void *pv, size_t size)
{
uint32_t *v = pv;
qemu_put_be32s(f, v);
}
const VMStateInfo vmstate_info_uint32 = {
.name = "uint32",
.get = get_uint32,
.put = put_uint32,
};
/* 32 bit uint. See that the received value is the same than the one
in the field */
static int get_uint32_equal(QEMUFile *f, void *pv, size_t size)
{
uint32_t *v = pv;
uint32_t v2;
qemu_get_be32s(f, &v2);
if (*v == v2) {
return 0;
}
return -EINVAL;
}
const VMStateInfo vmstate_info_uint32_equal = {
.name = "uint32 equal",
.get = get_uint32_equal,
.put = put_uint32,
};
/* 64 bit unsigned int */
static int get_uint64(QEMUFile *f, void *pv, size_t size)
{
uint64_t *v = pv;
qemu_get_be64s(f, v);
return 0;
}
static void put_uint64(QEMUFile *f, void *pv, size_t size)
{
uint64_t *v = pv;
qemu_put_be64s(f, v);
}
const VMStateInfo vmstate_info_uint64 = {
.name = "uint64",
.get = get_uint64,
.put = put_uint64,
};
/* 64 bit unsigned int. See that the received value is the same than the one
in the field */
static int get_uint64_equal(QEMUFile *f, void *pv, size_t size)
{
uint64_t *v = pv;
uint64_t v2;
qemu_get_be64s(f, &v2);
if (*v == v2) {
return 0;
}
return -EINVAL;
}
const VMStateInfo vmstate_info_uint64_equal = {
.name = "int64 equal",
.get = get_uint64_equal,
.put = put_uint64,
};
/* 8 bit int. See that the received value is the same than the one
in the field */
static int get_uint8_equal(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
uint8_t v2;
qemu_get_8s(f, &v2);
if (*v == v2) {
return 0;
}
return -EINVAL;
}
const VMStateInfo vmstate_info_uint8_equal = {
.name = "uint8 equal",
.get = get_uint8_equal,
.put = put_uint8,
};
/* 16 bit unsigned int int. See that the received value is the same than the one
in the field */
static int get_uint16_equal(QEMUFile *f, void *pv, size_t size)
{
uint16_t *v = pv;
uint16_t v2;
qemu_get_be16s(f, &v2);
if (*v == v2) {
return 0;
}
return -EINVAL;
}
const VMStateInfo vmstate_info_uint16_equal = {
.name = "uint16 equal",
.get = get_uint16_equal,
.put = put_uint16,
};
/* floating point */
static int get_float64(QEMUFile *f, void *pv, size_t size)
{
float64 *v = pv;
*v = make_float64(qemu_get_be64(f));
return 0;
}
static void put_float64(QEMUFile *f, void *pv, size_t size)
{
uint64_t *v = pv;
qemu_put_be64(f, float64_val(*v));
}
const VMStateInfo vmstate_info_float64 = {
.name = "float64",
.get = get_float64,
.put = put_float64,
};
/* uint8_t buffers */
static int get_buffer(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_get_buffer(f, v, size);
return 0;
}
static void put_buffer(QEMUFile *f, void *pv, size_t size)
{
uint8_t *v = pv;
qemu_put_buffer(f, v, size);
}
const VMStateInfo vmstate_info_buffer = {
.name = "buffer",
.get = get_buffer,
.put = put_buffer,
};
/* unused buffers: space that was used for some fields that are
not useful anymore */
static int get_unused_buffer(QEMUFile *f, void *pv, size_t size)
{
uint8_t buf[1024];
int block_len;
while (size > 0) {
block_len = MIN(sizeof(buf), size);
size -= block_len;
qemu_get_buffer(f, buf, block_len);
}
return 0;
}
static void put_unused_buffer(QEMUFile *f, void *pv, size_t size)
{
static const uint8_t buf[1024];
int block_len;
while (size > 0) {
block_len = MIN(sizeof(buf), size);
size -= block_len;
qemu_put_buffer(f, buf, block_len);
}
}
const VMStateInfo vmstate_info_unused_buffer = {
.name = "unused_buffer",
.get = get_unused_buffer,
.put = put_unused_buffer,
};
/* bitmaps (as defined by bitmap.h). Note that size here is the size
* of the bitmap in bits. The on-the-wire format of a bitmap is 64
* bit words with the bits in big endian order. The in-memory format
* is an array of 'unsigned long', which may be either 32 or 64 bits.
*/
/* This is the number of 64 bit words sent over the wire */
#define BITS_TO_U64S(nr) DIV_ROUND_UP(nr, 64)
static int get_bitmap(QEMUFile *f, void *pv, size_t size)
{
unsigned long *bmp = pv;
int i, idx = 0;
for (i = 0; i < BITS_TO_U64S(size); i++) {
uint64_t w = qemu_get_be64(f);
bmp[idx++] = w;
if (sizeof(unsigned long) == 4 && idx < BITS_TO_LONGS(size)) {
bmp[idx++] = w >> 32;
}
}
return 0;
}
static void put_bitmap(QEMUFile *f, void *pv, size_t size)
{
unsigned long *bmp = pv;
int i, idx = 0;
for (i = 0; i < BITS_TO_U64S(size); i++) {
uint64_t w = bmp[idx++];
if (sizeof(unsigned long) == 4 && idx < BITS_TO_LONGS(size)) {
w |= ((uint64_t)bmp[idx++]) << 32;
}
qemu_put_be64(f, w);
}
}
const VMStateInfo vmstate_info_bitmap = {
.name = "bitmap",
.get = get_bitmap,
.put = put_bitmap,
};