qga: implement qmp_guest_set_memory_blocks() for Linux with sysfs

We can change guest's online/offline state of memory blocks, by using
command 'guest-set-memory-blocks'.
Signed-off-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

qga/commands-posix.c

@@ -2232,7 +2232,35 @@ GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
 GuestMemoryBlockResponseList *
 qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
 {
-    error_set(errp, QERR_UNSUPPORTED);
+    GuestMemoryBlockResponseList *head, **link;
+    Error *local_err = NULL;
+
+    head = NULL;
+    link = &head;
+
+    while (mem_blks != NULL) {
+        GuestMemoryBlockResponse *result;
+        GuestMemoryBlockResponseList *entry;
+        GuestMemoryBlock *current_mem_blk = mem_blks->value;
+
+        result = g_malloc0(sizeof(*result));
+        result->phys_index = current_mem_blk->phys_index;
+        transfer_memory_block(current_mem_blk, false, result, &local_err);
+        if (local_err) { /* should never happen */
+            goto err;
+        }
+        entry = g_malloc0(sizeof *entry);
+        entry->value = result;
+
+        *link = entry;
+        link = &entry->next;
+        mem_blks = mem_blks->next;
+    }
+
+    return head;
+err:
+    qapi_free_GuestMemoryBlockResponseList(head);
+    error_propagate(errp, local_err);
     return NULL;
 }