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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] libxl: refactor toolstack save restore code
This patch does following things:
1. Document v1 format.
2. Factor out function to handle QEMU restore data and function to
handle v1 blob for restore path.
3. Refactor save function to generate different blobs in the order
specified in format specification.
4. Change functions to use "goto out" idiom.
No functional changes introduced.
Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
I wrote this patch when exploring the idea of have toolstack save / restore v2
to record max pages information. Though that idea has been abandon it wouldn't
hurt to have clearer code structure and documentation.
---
tools/libxl/libxl_dom.c | 247 +++++++++++++++++++++++++++++-------------------
1 file changed, 150 insertions(+), 97 deletions(-)
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 867172a..23c4691 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -1032,6 +1032,15 @@ struct libxl__physmap_info {
char name[];
};
+/* Bump version every time when toolstack saved data changes.
+ * Different types of data are arranged in the specified order.
+ *
+ * Version 1:
+ * uint32_t version
+ * QEMU physmap data:
+ * uint32_t count
+ * libxl__physmap_info * count
+ */
#define TOOLSTACK_SAVE_VERSION 1
static inline char *restore_helper(libxl__gc *gc, uint32_t dm_domid,
@@ -1043,66 +1052,97 @@ static inline char *restore_helper(libxl__gc *gc,
uint32_t dm_domid,
phys_offset, node);
}
-int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
- uint32_t size, void *user)
+static int libxl__toolstack_restore_qemu(libxl__gc *gc, uint32_t domid,
+ const uint8_t *buf, uint32_t size)
{
- libxl__save_helper_state *shs = user;
- libxl__domain_create_state *dcs = CONTAINER_OF(shs, *dcs, shs);
- STATE_AO_GC(dcs->ao);
- int i, ret;
- const uint8_t *ptr = buf;
- uint32_t count = 0, version = 0;
- struct libxl__physmap_info* pi;
+ int rc, i;
+ uint32_t count;
char *xs_path;
uint32_t dm_domid;
+ struct libxl__physmap_info *pi;
- LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, size);
-
- if (size < sizeof(version) + sizeof(count)) {
+ if (size < sizeof(count)) {
LOG(ERROR, "wrong size");
- return -1;
- }
-
- memcpy(&version, ptr, sizeof(version));
- ptr += sizeof(version);
-
- if (version != TOOLSTACK_SAVE_VERSION) {
- LOG(ERROR, "wrong version");
- return -1;
+ rc = -1;
+ goto out;
}
- memcpy(&count, ptr, sizeof(count));
- ptr += sizeof(count);
+ memcpy(&count, buf, sizeof(count));
+ buf += sizeof(count);
- if (size < sizeof(version) + sizeof(count) +
- count * (sizeof(struct libxl__physmap_info))) {
+ if (size < sizeof(count) + count*(sizeof(struct libxl__physmap_info))) {
LOG(ERROR, "wrong size");
- return -1;
+ rc = -1;
+ goto out;
}
dm_domid = libxl_get_stubdom_id(CTX, domid);
for (i = 0; i < count; i++) {
- pi = (struct libxl__physmap_info*) ptr;
- ptr += sizeof(struct libxl__physmap_info) + pi->namelen;
+ pi = (struct libxl__physmap_info*) buf;
+ buf += sizeof(struct libxl__physmap_info) + pi->namelen;
xs_path = restore_helper(gc, dm_domid, domid,
pi->phys_offset, "start_addr");
- ret = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->start_addr);
- if (ret)
- return -1;
+ rc = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->start_addr);
+ if (rc) goto out;
+
xs_path = restore_helper(gc, dm_domid, domid, pi->phys_offset, "size");
- ret = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->size);
- if (ret)
- return -1;
+ rc = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->size);
+ if (rc) goto out;
+
if (pi->namelen > 0) {
xs_path = restore_helper(gc, dm_domid, domid,
pi->phys_offset, "name");
- ret = libxl__xs_write(gc, 0, xs_path, "%s", pi->name);
- if (ret)
- return -1;
+ rc = libxl__xs_write(gc, 0, xs_path, "%s", pi->name);
+ if (rc) goto out;
}
}
- return 0;
+
+ rc = 0;
+out:
+ return rc;
+
+}
+
+static int libxl__toolstack_restore_v1(libxl__gc *gc, uint32_t domid,
+ const uint8_t *buf, uint32_t size)
+{
+ return libxl__toolstack_restore_qemu(gc, domid, buf, size);
+}
+
+int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
+ uint32_t size, void *user)
+{
+ libxl__save_helper_state *shs = user;
+ libxl__domain_create_state *dcs = CONTAINER_OF(shs, *dcs, shs);
+ STATE_AO_GC(dcs->ao);
+ int rc;
+ const uint8_t *ptr = buf;
+ uint32_t version = 0, bufsize;
+
+ LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, size);
+
+ if (size < sizeof(version)) {
+ LOG(ERROR, "wrong size");
+ rc = -1;
+ goto out;
+ }
+
+ memcpy(&version, ptr, sizeof(version));
+ ptr += sizeof(version);
+ bufsize = size - sizeof(version);
+
+ switch (version) {
+ case 1:
+ rc = libxl__toolstack_restore_v1(gc, domid, ptr, bufsize);
+ break;
+ default:
+ LOG(ERROR, "wrong version");
+ rc = -1;
+ }
+
+out:
+ return rc;
}
/*==================== Domain suspend (save) ====================*/
@@ -1685,81 +1725,94 @@ int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
uint32_t *len, void *dss_void)
{
libxl__domain_suspend_state *dss = dss_void;
+ int rc;
STATE_AO_GC(dss->ao);
int i = 0;
- char *start_addr = NULL, *size = NULL, *phys_offset = NULL, *name = NULL;
- unsigned int num = 0;
- uint32_t count = 0, version = TOOLSTACK_SAVE_VERSION, namelen = 0;
+ uint32_t version = TOOLSTACK_SAVE_VERSION;
uint8_t *ptr = NULL;
- char **entries = NULL;
- struct libxl__physmap_info *pi;
- uint32_t dm_domid;
-
- dm_domid = libxl_get_stubdom_id(CTX, domid);
- entries = libxl__xs_directory(gc, 0,
- libxl__device_model_xs_path(gc, dm_domid, domid, "/physmap"),
- &num);
- count = num;
+ rc = -1;
- *len = sizeof(version) + sizeof(count);
+ /* Version number */
+ *len = sizeof(version);
*buf = calloc(1, *len);
+ if (*buf == NULL) goto out;
ptr = *buf;
- if (*buf == NULL)
- return -1;
-
memcpy(ptr, &version, sizeof(version));
- ptr += sizeof(version);
- memcpy(ptr, &count, sizeof(count));
- ptr += sizeof(count);
- for (i = 0; i < count; i++) {
- unsigned long offset;
- char *xs_path;
- phys_offset = entries[i];
- if (phys_offset == NULL) {
- LOG(ERROR, "phys_offset %d is NULL", i);
- return -1;
- }
+ /* QEMU physmap data */
+ {
+ char **entries = NULL, *xs_path;
+ struct libxl__physmap_info *pi;
+ uint32_t dm_domid;
+ char *start_addr = NULL, *size = NULL, *phys_offset = NULL;
+ char *name = NULL;
+ unsigned int num = 0;
+ uint32_t count = 0, namelen = 0;
+
+ dm_domid = libxl_get_stubdom_id(CTX, domid);
+
+ xs_path = libxl__device_model_xs_path(gc, dm_domid, domid,
+ "/physmap");
+ entries = libxl__xs_directory(gc, 0, xs_path, &num);
+ count = num;
+
+ *len += sizeof(count);
+ *buf = realloc(*buf, *len);
+ if (*buf == NULL) goto out;
+ ptr = *buf + sizeof(version);
+ memcpy(ptr, &count, sizeof(count));
+ ptr += sizeof(count);
+
+ for (i = 0; i < count; i++) {
+ unsigned long offset;
+ phys_offset = entries[i];
+ if (phys_offset == NULL) {
+ LOG(ERROR, "phys_offset %d is NULL", i);
+ goto out;
+ }
- xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "start_addr");
- start_addr = libxl__xs_read(gc, 0, xs_path);
- if (start_addr == NULL) {
- LOG(ERROR, "%s is NULL", xs_path);
- return -1;
- }
+ xs_path = physmap_path(gc, dm_domid, domid, phys_offset,
+ "start_addr");
+ start_addr = libxl__xs_read(gc, 0, xs_path);
+ if (start_addr == NULL) {
+ LOG(ERROR, "%s is NULL", xs_path);
+ goto out;
+ }
- xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "size");
- size = libxl__xs_read(gc, 0, xs_path);
- if (size == NULL) {
- LOG(ERROR, "%s is NULL", xs_path);
- return -1;
- }
+ xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "size");
+ size = libxl__xs_read(gc, 0, xs_path);
+ if (size == NULL) {
+ LOG(ERROR, "%s is NULL", xs_path);
+ goto out;
+ }
- xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "name");
- name = libxl__xs_read(gc, 0, xs_path);
- if (name == NULL)
- namelen = 0;
- else
- namelen = strlen(name) + 1;
- *len += namelen + sizeof(struct libxl__physmap_info);
- offset = ptr - (*buf);
- *buf = realloc(*buf, *len);
- if (*buf == NULL)
- return -1;
- ptr = (*buf) + offset;
- pi = (struct libxl__physmap_info *) ptr;
- pi->phys_offset = strtoll(phys_offset, NULL, 16);
- pi->start_addr = strtoll(start_addr, NULL, 16);
- pi->size = strtoll(size, NULL, 16);
- pi->namelen = namelen;
- memcpy(pi->name, name, namelen);
- ptr += sizeof(struct libxl__physmap_info) + namelen;
+ xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "name");
+ name = libxl__xs_read(gc, 0, xs_path);
+ if (name == NULL)
+ namelen = 0;
+ else
+ namelen = strlen(name) + 1;
+ *len += namelen + sizeof(struct libxl__physmap_info);
+ offset = ptr - (*buf);
+ *buf = realloc(*buf, *len);
+ if (*buf == NULL) goto out;
+ ptr = (*buf) + offset;
+ pi = (struct libxl__physmap_info *) ptr;
+ pi->phys_offset = strtoll(phys_offset, NULL, 16);
+ pi->start_addr = strtoll(start_addr, NULL, 16);
+ pi->size = strtoll(size, NULL, 16);
+ pi->namelen = namelen;
+ memcpy(pi->name, name, namelen);
+ ptr += sizeof(struct libxl__physmap_info) + namelen;
+ }
}
LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, *len);
- return 0;
+ rc = 0;
+out:
+ return rc;
}
static void libxl__domain_suspend_callback(void *data)
--
1.9.1
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