for (i = 0; i < 6; i++)
(*dst)[i] = (*src)[i];
}
+
+int libxl_retrieve_domain_configuration(libxl_ctx *ctx, uint32_t domid,
+ libxl_domain_config *d_config)
+{
+ GC_INIT(ctx);
+ int rc;
+ libxl__domain_userdata_lock *lock = NULL;
+
+ CTX_LOCK;
+
+ lock = libxl__lock_domain_userdata(gc, domid);
+ if (!lock) {
+ rc = ERROR_LOCK_FAIL;
+ goto out;
+ }
+
+ rc = libxl__get_domain_configuration(gc, domid, d_config);
+ if (rc) {
+ LOG(ERROR, "fail to get domain configuration for domain %d", domid);
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ /* Domain name */
+ {
+ char *domname;
+ domname = libxl_domid_to_name(ctx, domid);
+ if (!domname) {
+ LOG(ERROR, "fail to get domain name for domain %d", domid);
+ goto out;
+ }
+ free(d_config->c_info.name);
+ d_config->c_info.name = domname; /* steals allocation */
+ }
+
+ /* Domain UUID */
+ {
+ libxl_dominfo info;
+ rc = libxl_domain_info(ctx, &info, domid);
+ if (rc) {
+ LOG(ERROR, "fail to get domain info for domain %d", domid);
+ goto out;
+ }
+ libxl_uuid_copy(ctx, &d_config->c_info.uuid, &info.uuid);
+ }
+
+ /* Memory limits:
+ *
+ * Currently there are three memory limits:
+ * 1. "target" in xenstore (originally memory= in config file)
+ * 2. "static-max" in xenstore (originally maxmem= in config file)
+ * 3. "max_memkb" in hypervisor
+ *
+ * The third one is not visible and currently managed by
+ * toolstack. In order to rebuild a domain we only need to have
+ * "target" and "static-max".
+ */
+ {
+ uint32_t target_memkb = 0, max_memkb = 0;
+
+ /* "target" */
+ rc = libxl__get_memory_target(gc, domid, &target_memkb, &max_memkb);
+ if (rc) {
+ LOG(ERROR, "fail to get memory target for domain %d", domid);
+ goto out;
+ }
+ /* Target memory in xenstore is different from what user has
+ * asked for. The difference is video_memkb. See
+ * libxl_set_memory_target.
+ */
+ d_config->b_info.target_memkb = target_memkb +
+ d_config->b_info.video_memkb;
+
+ d_config->b_info.max_memkb = max_memkb;
+ }
+
+ /* Devices: disk, nic, vtpm, pcidev etc. */
+
+ /* The MERGE macro implements following logic:
+ * 0. retrieve JSON (done by now)
+ * 1. retrieve list of device from xenstore
+ * 2. use xenstore entries as primary reference and compare JSON
+ * entries with them.
+ * a. if a device is present in xenstore and in JSON, merge the
+ * two views.
+ * b. if a device is not present in xenstore but in JSON, delete
+ * it from the result.
+ * c. it's impossible to have an entry present in xenstore but
+ * not in JSON, because we maintain an invariant that every
+ * entry in xenstore must have a corresponding entry in JSON.
+ * 3. "merge" operates on "src" and "dst". "src" points to the
+ * entry retrieved from xenstore while "dst" points to the entry
+ * retrieve from JSON.
+ */
+#define MERGE(type, ptr, compare, merge) \
+ do { \
+ libxl_device_##type *p = NULL; \
+ int i, j, num; \
+ \
+ p = libxl_device_##type##_list(CTX, domid, &num); \
+ if (p == NULL) { \
+ LOG(DEBUG, \
+ "no %s from xenstore for domain %d", \
+ #type, domid); \
+ } \
+ \
+ for (i = 0; i < d_config->num_##ptr; i++) { \
+ libxl_device_##type *q = &d_config->ptr[i]; \
+ for (j = 0; j < num; j++) { \
+ if (compare(&p[j], q)) \
+ break; \
+ } \
+ \
+ if (j < num) { /* found in xenstore */ \
+ libxl_device_##type *dst, *src; \
+ dst = q; \
+ src = &p[j]; \
+ merge; \
+ } else { /* not found in xenstore */ \
+ LOG(WARN, \
+ "Device present in JSON but not in xenstore, ignored"); \
+ \
+ libxl_device_##type##_dispose(q); \
+ \
+ for (j = i; j < d_config->num_##ptr - 1; j++) \
+ memcpy(&d_config->ptr[j], &d_config->ptr[j+1], \
+ sizeof(libxl_device_##type)); \
+ \
+ d_config->ptr = \
+ libxl__realloc(NOGC, d_config->ptr, \
+ sizeof(libxl_device_##type) * \
+ (d_config->num_##ptr - 1)); \
+ \
+ /* rewind counters */ \
+ d_config->num_##ptr--; \
+ i--; \
+ } \
+ } \
+ \
+ for (i = 0; i < num; i++) \
+ libxl_device_##type##_dispose(&p[i]); \
+ free(p); \
+ } while (0);
+
+ MERGE(nic, nics, COMPARE_DEVID, {});
+
+ MERGE(vtpm, vtpms, COMPARE_DEVID, {});
+
+ MERGE(pci, pcidevs, COMPARE_PCI, {});
+
+ /* Take care of removable device. We maintain invariant in the
+ * insert / remove operation so that:
+ * 1. if xenstore is "empty" while JSON is not, the result
+ * is "empty"
+ * 2. if xenstore has a different media than JSON, use the
+ * one in JSON
+ * 3. if xenstore and JSON have the same media, well, you
+ * know the answer :-)
+ *
+ * Currently there is only one removable device -- CDROM.
+ * Look for libxl_cdrom_insert for reference.
+ */
+ MERGE(disk, disks, COMPARE_DISK, {
+ if (src->removable) {
+ if (!src->pdev_path || *src->pdev_path == '\0') {
+ /* 1, no media in drive */
+ free(dst->pdev_path);
+ dst->pdev_path = libxl__strdup(NOGC, "");
+ dst->format = LIBXL_DISK_FORMAT_EMPTY;
+ } else {
+ /* 2 and 3, use JSON, no need to touch anything */
+ ;
+ }
+ }
+ });
+
+#undef MERGE
+
+out:
+ if (lock) libxl__unlock_domain_userdata(lock);
+ CTX_UNLOCK;
+ GC_FREE;
+ return rc;
+}
+
/*
* Local variables:
* mode: C
projects / xen.git / commitdiff