diff options
| -rw-r--r-- | qga/commands-posix.c | 233 |
1 files changed, 232 insertions, 1 deletions
diff --git a/qga/commands-posix.c b/qga/commands-posix.c index b7b7efe2ec..5d4101dc79 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -1992,9 +1992,240 @@ out: } } +static void ga_read_sysfs_file(int dirfd, const char *pathname, char *buf, + int size, Error **errp) +{ + int fd; + int res; + + errno = 0; + fd = openat(dirfd, pathname, O_RDONLY); + if (fd == -1) { + error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname); + return; + } + + res = pread(fd, buf, size, 0); + if (res == -1) { + error_setg_errno(errp, errno, "pread sysfs file \"%s\"", pathname); + } else if (res == 0) { + error_setg(errp, "pread sysfs file \"%s\": unexpected EOF", pathname); + } + close(fd); +} + +static void ga_write_sysfs_file(int dirfd, const char *pathname, + const char *buf, int size, Error **errp) +{ + int fd; + + errno = 0; + fd = openat(dirfd, pathname, O_WRONLY); + if (fd == -1) { + error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname); + return; + } + + if (pwrite(fd, buf, size, 0) == -1) { + error_setg_errno(errp, errno, "pwrite sysfs file \"%s\"", pathname); + } + + close(fd); +} + +/* Transfer online/offline status between @mem_blk and the guest system. + * + * On input either @errp or *@errp must be NULL. + * + * In system-to-@mem_blk direction, the following @mem_blk fields are accessed: + * - R: mem_blk->phys_index + * - W: mem_blk->online + * - W: mem_blk->can_offline + * + * In @mem_blk-to-system direction, the following @mem_blk fields are accessed: + * - R: mem_blk->phys_index + * - R: mem_blk->online + *- R: mem_blk->can_offline + * Written members remain unmodified on error. + */ +static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk, + GuestMemoryBlockResponse *result, + Error **errp) +{ + char *dirpath; + int dirfd; + char *status; + Error *local_err = NULL; + + if (!sys2memblk) { + DIR *dp; + + if (!result) { + error_setg(errp, "Internal error, 'result' should not be NULL"); + return; + } + errno = 0; + dp = opendir("/sys/devices/system/memory/"); + /* if there is no 'memory' directory in sysfs, + * we think this VM does not support online/offline memory block, + * any other solution? + */ + if (!dp && errno == ENOENT) { + result->response = + GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED; + goto out1; + } + closedir(dp); + } + + dirpath = g_strdup_printf("/sys/devices/system/memory/memory%" PRId64 "/", + mem_blk->phys_index); + dirfd = open(dirpath, O_RDONLY | O_DIRECTORY); + if (dirfd == -1) { + if (sys2memblk) { + error_setg_errno(errp, errno, "open(\"%s\")", dirpath); + } else { + if (errno == ENOENT) { + result->response = GUEST_MEMORY_BLOCK_RESPONSE_TYPE_NOT_FOUND; + } else { + result->response = + GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED; + } + } + g_free(dirpath); + goto out1; + } + g_free(dirpath); + + status = g_malloc0(10); + ga_read_sysfs_file(dirfd, "state", status, 10, &local_err); + if (local_err) { + /* treat with sysfs file that not exist in old kernel */ + if (errno == ENOENT) { + error_free(local_err); + if (sys2memblk) { + mem_blk->online = true; + mem_blk->can_offline = false; + } else if (!mem_blk->online) { + result->response = + GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED; + } + } else { + if (sys2memblk) { + error_propagate(errp, local_err); + } else { + result->response = + GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED; + } + } + goto out2; + } + + if (sys2memblk) { + char removable = '0'; + + mem_blk->online = (strncmp(status, "online", 6) == 0); + + ga_read_sysfs_file(dirfd, "removable", &removable, 1, &local_err); + if (local_err) { + /* if no 'removable' file, it does't support offline mem blk */ + if (errno == ENOENT) { + error_free(local_err); + mem_blk->can_offline = false; + } else { + error_propagate(errp, local_err); + } + } else { + mem_blk->can_offline = (removable != '0'); + } + } else { + if (mem_blk->online != (strncmp(status, "online", 6) == 0)) { + char *new_state = mem_blk->online ? g_strdup("online") : + g_strdup("offline"); + + ga_write_sysfs_file(dirfd, "state", new_state, strlen(new_state), + &local_err); + g_free(new_state); + if (local_err) { + error_free(local_err); + result->response = + GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED; + goto out2; + } + + result->response = GUEST_MEMORY_BLOCK_RESPONSE_TYPE_SUCCESS; + result->has_error_code = false; + } /* otherwise pretend successful re-(on|off)-lining */ + } + g_free(status); + close(dirfd); + return; + +out2: + g_free(status); + close(dirfd); +out1: + if (!sys2memblk) { + result->has_error_code = true; + result->error_code = errno; + } +} + GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp) { - error_set(errp, QERR_UNSUPPORTED); + GuestMemoryBlockList *head, **link; + Error *local_err = NULL; + struct dirent *de; + DIR *dp; + + head = NULL; + link = &head; + + dp = opendir("/sys/devices/system/memory/"); + if (!dp) { + error_setg_errno(errp, errno, "Can't open directory" + "\"/sys/devices/system/memory/\"\n"); + return NULL; + } + + /* Note: the phys_index of memory block may be discontinuous, + * this is because a memblk is the unit of the Sparse Memory design, which + * allows discontinuous memory ranges (ex. NUMA), so here we should + * traverse the memory block directory. + */ + while ((de = readdir(dp)) != NULL) { + GuestMemoryBlock *mem_blk; + GuestMemoryBlockList *entry; + + if ((strncmp(de->d_name, "memory", 6) != 0) || + !(de->d_type & DT_DIR)) { + continue; + } + + mem_blk = g_malloc0(sizeof *mem_blk); + /* The d_name is "memoryXXX", phys_index is block id, same as XXX */ + mem_blk->phys_index = strtoul(&de->d_name[6], NULL, 10); + mem_blk->has_can_offline = true; /* lolspeak ftw */ + transfer_memory_block(mem_blk, true, NULL, &local_err); + + entry = g_malloc0(sizeof *entry); + entry->value = mem_blk; + + *link = entry; + link = &entry->next; + } + + closedir(dp); + if (local_err == NULL) { + /* there's no guest with zero memory blocks */ + if (head == NULL) { + error_setg(errp, "guest reported zero memory blocks!"); + } + return head; + } + + qapi_free_GuestMemoryBlockList(head); + error_propagate(errp, local_err); return NULL; } |