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-rw-r--r--Makefile.objs2
-rw-r--r--blockdev-nbd.c119
-rw-r--r--qapi-schema.json43
-rw-r--r--qmp-commands.hx16
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,