diff options
| -rw-r--r-- | Makefile.objs | 2 | ||||
| -rw-r--r-- | blockdev-nbd.c | 119 | ||||
| -rw-r--r-- | qapi-schema.json | 43 | ||||
| -rw-r--r-- | qmp-commands.hx | 16 |
4 files changed, 179 insertions, 1 deletions
diff --git a/Makefile.objs b/Makefile.objs index ca67885778..9eca179903 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -61,7 +61,7 @@ endif # suppress *all* target specific code in case of system emulation, i.e. a # single QEMU executable should support all CPUs and machines. -common-obj-y = $(block-obj-y) blockdev.o block/ +common-obj-y = $(block-obj-y) blockdev.o blockdev-nbd.o block/ common-obj-y += net.o net/ common-obj-y += qom/ common-obj-y += readline.o console.o cursor.o diff --git a/blockdev-nbd.c b/blockdev-nbd.c new file mode 100644 index 0000000000..8031813071 --- /dev/null +++ b/blockdev-nbd.c @@ -0,0 +1,119 @@ +/* + * Serving QEMU block devices via NBD + * + * Copyright (c) 2012 Red Hat, Inc. + * + * Author: Paolo Bonzini <pbonzini@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#include "blockdev.h" +#include "hw/block-common.h" +#include "monitor.h" +#include "qerror.h" +#include "sysemu.h" +#include "qmp-commands.h" +#include "trace.h" +#include "nbd.h" +#include "qemu_socket.h" + +static int server_fd = -1; + +static void nbd_accept(void *opaque) +{ + struct sockaddr_in addr; + socklen_t addr_len = sizeof(addr); + + int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); + if (fd >= 0) { + nbd_client_new(NULL, fd, nbd_client_put); + } +} + +void qmp_nbd_server_start(SocketAddress *addr, Error **errp) +{ + if (server_fd != -1) { + error_setg(errp, "NBD server already running"); + return; + } + + server_fd = socket_listen(addr, errp); + if (server_fd != -1) { + qemu_set_fd_handler2(server_fd, NULL, nbd_accept, NULL, NULL); + } +} + +/* Hook into the BlockDriverState notifiers to close the export when + * the file is closed. + */ +typedef struct NBDCloseNotifier { + Notifier n; + NBDExport *exp; + QTAILQ_ENTRY(NBDCloseNotifier) next; +} NBDCloseNotifier; + +static QTAILQ_HEAD(, NBDCloseNotifier) close_notifiers = + QTAILQ_HEAD_INITIALIZER(close_notifiers); + +static void nbd_close_notifier(Notifier *n, void *data) +{ + NBDCloseNotifier *cn = DO_UPCAST(NBDCloseNotifier, n, n); + + notifier_remove(&cn->n); + QTAILQ_REMOVE(&close_notifiers, cn, next); + + nbd_export_close(cn->exp); + nbd_export_put(cn->exp); + g_free(cn); +} + +static void nbd_server_put_ref(NBDExport *exp) +{ + BlockDriverState *bs = nbd_export_get_blockdev(exp); + drive_put_ref(drive_get_by_blockdev(bs)); +} + +void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, + Error **errp) +{ + BlockDriverState *bs; + NBDExport *exp; + NBDCloseNotifier *n; + + if (nbd_export_find(device)) { + error_setg(errp, "NBD server already exporting device '%s'", device); + return; + } + + bs = bdrv_find(device); + if (!bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, device); + return; + } + + exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, + nbd_server_put_ref); + + nbd_export_set_name(exp, device); + drive_get_ref(drive_get_by_blockdev(bs)); + + n = g_malloc0(sizeof(NBDCloseNotifier)); + n->n.notify = nbd_close_notifier; + n->exp = exp; + bdrv_add_close_notifier(bs, &n->n); + QTAILQ_INSERT_TAIL(&close_notifiers, n, next); +} + +void qmp_nbd_server_stop(Error **errp) +{ + while (!QTAILQ_EMPTY(&close_notifiers)) { + NBDCloseNotifier *cn = QTAILQ_FIRST(&close_notifiers); + nbd_close_notifier(&cn->n, nbd_export_get_blockdev(cn->exp)); + } + + qemu_set_fd_handler2(server_fd, NULL, NULL, NULL, NULL); + close(server_fd); + server_fd = -1; +} diff --git a/qapi-schema.json b/qapi-schema.json index 8468567bfb..6fd263e646 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -2863,3 +2863,46 @@ # Since: 0.14.0 ## { 'command': 'screendump', 'data': {'filename': 'str'} } + +## +# @nbd-server-start: +# +# Start an NBD server listening on the given host and port. Block +# devices can then be exported using @nbd-server-add. The NBD +# server will present them as named exports; for example, another +# QEMU instance could refer to them as "nbd:HOST:PORT:exportname=NAME". +# +# @addr: Address on which to listen. +# +# Returns: error if the server is already running. +# +# Since: 1.3.0 +## +{ 'command': 'nbd-server-start', + 'data': { 'addr': 'SocketAddress' } } + +## +# @nbd-server-add: +# +# Export a device to QEMU's embedded NBD server. +# +# @device: Block device to be exported +# +# @writable: Whether clients should be able to write to the device via the +# NBD connection (default false). #optional +# +# Returns: error if the device is already marked for export. +# +# Since: 1.3.0 +## +{ 'command': 'nbd-server-add', 'data': {'device': 'str', '*writable': 'bool'} } + +## +# @nbd-server-stop: +# +# Stop QEMU's embedded NBD server, and unregister all devices previously +# added via @nbd-server-add. +# +# Since: 1.3.0 +## +{ 'command': 'nbd-server-stop' } diff --git a/qmp-commands.hx b/qmp-commands.hx index 5ba8c48cb4..ebe9a78ca9 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -2552,6 +2552,22 @@ EQMP }, { + .name = "nbd-server-start", + .args_type = "addr:q", + .mhandler.cmd_new = qmp_marshal_input_nbd_server_start, + }, + { + .name = "nbd-server-add", + .args_type = "device:B,writable:b?", + .mhandler.cmd_new = qmp_marshal_input_nbd_server_add, + }, + { + .name = "nbd-server-stop", + .args_type = "", + .mhandler.cmd_new = qmp_marshal_input_nbd_server_stop, + }, + + { .name = "change-vnc-password", .args_type = "password:s", .mhandler.cmd_new = qmp_marshal_input_change_vnc_password, |