The new EMULATOR_XENSTORE_DATA content is a sequence of NUL terminated
key/value strings, with the key relative to the device model's xenstore
tree.
A sample might look like (as decoded by verify-stream-v2):
Emulator Xenstore Data (Qemu Upstream, idx 0)
'physmap/1f00000/start_addr' = 'f0000000'
'physmap/1f00000/size' = '800000'
'physmap/1f00000/name' = 'vga.vram'
This patch introduces libxl helpers to save and restore this new format.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Ian Campbell <ian.campb...@citrix.com>
CC: Ian Jackson <ian.jack...@eu.citrix.com>
CC: Wei Liu <wei.l...@citrix.com>
---
tools/libxl/libxl_dom.c | 141 ++++++++++++++++++++++++++++++++++++++++++
tools/libxl/libxl_internal.h | 4 ++
2 files changed, 145 insertions(+)
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 5555fea..885eb5e 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -1151,6 +1151,65 @@ int libxl__toolstack_restore(uint32_t domid, const
uint8_t *ptr,
return ret;
}
+int libxl__restore_emulator_xenstore_data(libxl__domain_create_state *dcs,
+ const char *ptr, uint32_t size)
+{
+ STATE_AO_GC(dcs->ao);
+ const char *key = ptr, *val;
+ int rc;
+
+ const uint32_t domid = dcs->guest_domid;
+ const uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
+ const char *xs_root = libxl__device_model_xs_path(gc, dm_domid, domid, "");
+
+ while ( size ) {
+ /* Sanitise key. */
+ size_t keylen = strnlen(key, size);
+
+ if ( keylen == size ) {
+ rc = ERROR_FAIL;
+ LOG(ERROR, "Key in xenstore data not NUL terminated");
+ goto out;
+ }
+ if ( keylen == 0 ) {
+ rc = ERROR_FAIL;
+ LOG(ERROR, "NULL key found in xenstore data");
+ goto out;
+ }
+ if ( key[0] == '/' ) {
+ rc = ERROR_FAIL;
+ LOG(ERROR, "Key in xenstore data not relative");
+ goto out;
+ }
+
+ size -= (keylen + 1);
+
+ /* The val string starts after the NUL terminator of key. */
+ val = key + keylen + 1;
+
+ /* Sanitise val. */
+ size_t vallen = strnlen(val, size);
+
+ if ( vallen == size ) {
+ rc = ERROR_FAIL;
+ LOG(ERROR, "Val in xenstore data not NUL terminated");
+ goto out;
+ }
+
+ size -= (vallen + 1);
+
+ libxl__xs_write(gc, 0, GCSPRINTF("%s/%s", xs_root, key), "%s", val);
+
+ /* Move key forwards over the key and value pair just written. */
+ key = key + keylen + vallen + 2;
+ }
+
+ rc = 0;
+
+ out:
+ return rc;
+}
+
/*==================== Domain suspend (save) ====================*/
static void stream_done(libxl__egc *egc,
@@ -1487,6 +1546,88 @@ int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
return ret;
}
+int libxl__save_emulator_xenstore_data(libxl__domain_suspend_state *dss,
+ uint8_t **callee_buf,
+ uint32_t *callee_len)
+{
+ STATE_AO_GC(dss->ao);
+ const char *xs_path;
+ char **entries, *ptr, *buf = NULL;
+ unsigned int nr_entries, rel_start, i, len = 0;
+ int rc;
+
+ const uint32_t domid = dss->domid;
+ const uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
+
+ xs_path = libxl__device_model_xs_path(gc, dm_domid, domid, "/physmap");
+ if (!xs_path) { rc = 0; goto out; }
+
+ /* &foo[rel_start] is the xenstore path starting at the 'p' of physmap */
+ rel_start = strlen(xs_path) - 7;
+
+ entries = libxl__xs_directory(gc, 0, xs_path, &nr_entries);
+ if (!entries || nr_entries == 0) { rc = 0; goto out; }
+
+ for (i = 0; i < nr_entries; ++i) {
+ const char *start_addr, *start_addr_val,
+ *size, *size_val, *name, *name_val;
+
+ start_addr = libxl__device_model_xs_path(
+ gc, dm_domid, domid, "/physmap/%s/start_addr", entries[i]);
+ size = libxl__device_model_xs_path(
+ gc, dm_domid, domid, "/physmap/%s/size", entries[i]);
+ name = libxl__device_model_xs_path(
+ gc, dm_domid, domid, "/physmap/%s/name", entries[i]);
+
+ if (!start_addr || !size || !name) { rc = ERROR_FAIL; goto out; }
+
+ start_addr_val = libxl__xs_read(gc, 0, start_addr);
+ size_val = libxl__xs_read(gc, 0, size);
+ name_val = libxl__xs_read(gc, 0, name);
+
+ if (!start_addr_val || !size_val || !name_val) {
+ rc = ERROR_FAIL; goto out;
+ }
+
+ /*
+ * Appends 's' to 'buf', including a NUL teriminator. Mutates
+ * 'buf', 'ptr' and 'len' in scope.
+ */
+#define APPEND_STRING(s) ({ \
+ size_t sz = strlen(s) + 1; \
+ ptr = realloc(buf, len + sz); \
+ if (!ptr) { rc = ERROR_NOMEM; goto out; } \
+ buf = ptr; \
+ strcpy(&buf[len], s); \
+ len += sz; \
+ buf[len - 1] = '\0'; \
+ })
+
+ APPEND_STRING(&start_addr[rel_start]);
+ APPEND_STRING(start_addr_val);
+
+ APPEND_STRING(&size[rel_start]);
+ APPEND_STRING(size_val);
+
+ APPEND_STRING(&name[rel_start]);
+ APPEND_STRING(name_val);
+
+#undef APPEND_STRING
+ }
+
+ rc = 0;
+
+ out:
+ if (rc)
+ free(buf);
+ else {
+ *callee_buf = (uint8_t *)buf;
+ *callee_len = len;
+ }
+
+ return rc;
+}
+
/*----- remus callbacks -----*/
static void remus_domain_suspend_callback_common_done(libxl__egc *egc,
libxl__domain_suspend_state *dss, int ok);
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 911de2d..8426221 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3439,6 +3439,10 @@ void
libxl__xc_domain_saverestore_async_callback_done(libxl__egc *egc,
(int domid, unsigned int enable, void *data);
_hidden int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
uint32_t *len, void *data);
+_hidden int libxl__save_emulator_xenstore_data(libxl__domain_suspend_state
*dss,
+ uint8_t **buf, uint32_t *len);
+_hidden int libxl__restore_emulator_xenstore_data(
+ libxl__domain_create_state *dcs, const char *ptr, uint32_t size);
/* calls libxl__xc_domain_restore_done when done */
--
1.7.10.4
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