vhost-user-blk can have played as vhost-user backend but it only supports raw file and don't support VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES operations on raw file (ioctl(fd, BLKDISCARD) is only valid for real block device).
Signed-off-by: Coiby Xu <coiby...@gmail.com> --- qemu-vu.c | 264 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 qemu-vu.c diff --git a/qemu-vu.c b/qemu-vu.c new file mode 100644 index 0000000000..25c32c2c6d --- /dev/null +++ b/qemu-vu.c @@ -0,0 +1,264 @@ +/* + * Copyright (C) 2020 Coiby Xu <coiby...@gmail.com> + * + * Vhost-user-blk device backend + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; under version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include <getopt.h> +#include <libgen.h> +#include "block/vhost-user.h" +#include "qemu-common.h" +#include "qapi/error.h" +#include "qemu/cutils.h" +#include "sysemu/block-backend.h" +#include "block/block_int.h" +#include "qemu/main-loop.h" +#include "qemu/module.h" +#include "qemu/option.h" +#include "qemu/error-report.h" +#include "qapi/qmp/qdict.h" +#include "qapi/qmp/qstring.h" +#include "qom/object_interfaces.h" +#include "io/net-listener.h" +#include "qemu-version.h" + +#define QEMU_VU_OPT_CACHE 256 + +#define QEMU_VU_OPT_AIO 257 + +static char *srcpath; + +static void usage(const char *name) +{ + (printf) ( +"Usage: %s [OPTIONS] FILE\n" +" or: %s -L [OPTIONS]\n" +"QEMU Vhost-user Server Utility\n" +"\n" +" -h, --help display this help and exit\n" +" -V, --version output version information and exit\n" +"\n" +"Connection properties:\n" +" -k, --socket=PATH path to the unix socket\n" +"\n" +"General purpose options:\n" +" -e, -- exit-panic When the panic callback is called, the program\n" +" will exit. Useful for make check-qtest.\n" +"\n" +"Block device options:\n" +" -f, --format=FORMAT set image format (raw, qcow2, ...)\n" +" -r, --read-only export read-only\n" +" -n, --nocache disable host cache\n" +" --cache=MODE set cache mode (none, writeback, ...)\n" +" --aio=MODE set AIO mode (native or threads)\n" +"\n" +QEMU_HELP_BOTTOM "\n" + , name, name); +} + +static void version(const char *name) +{ + printf( +"%s " QEMU_FULL_VERSION "\n" +"Written by Coiby Xu, based on qemu-nbd by Anthony Liguori\n" +"\n" +QEMU_COPYRIGHT "\n" +"This is free software; see the source for copying conditions. There is NO\n" +"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" + , name); +} + +static VubDev *vub_device; + +static void vus_shutdown(void) +{ + job_cancel_sync_all(); + bdrv_close_all(); + vub_free(vub_device, false); +} + +int main(int argc, char **argv) +{ + BlockBackend *blk; + BlockDriverState *bs; + bool readonly = false; + char *sockpath = NULL; + int64_t fd_size; + const char *sopt = "hVrnvek:f:"; + struct option lopt[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, 'V' }, + { "exit-panic", no_argument, NULL, 'e' }, + { "socket", required_argument, NULL, 'k' }, + { "read-only", no_argument, NULL, 'r' }, + { "nocache", no_argument, NULL, 'n' }, + { "cache", required_argument, NULL, QEMU_VU_OPT_CACHE }, + { "aio", required_argument, NULL, QEMU_VU_OPT_AIO }, + { "format", required_argument, NULL, 'f' }, + { NULL, 0, NULL, 0 } + }; + int ch; + int opt_ind = 0; + int flags = BDRV_O_RDWR; + bool seen_cache = false; + bool seen_aio = false; + const char *fmt = NULL; + Error *local_err = NULL; + QDict *options = NULL; + bool writethrough = true; + bool exit_panic = false; + + error_init(argv[0]); + + module_call_init(MODULE_INIT_QOM); + qemu_init_exec_dir(argv[0]); + + while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { + switch (ch) { + case 'e': + exit_panic = true; + break; + case 'n': + optarg = (char *) "none"; + /* fallthrough */ + case QEMU_VU_OPT_CACHE: + if (seen_cache) { + error_report("-n and --cache can only be specified once"); + exit(EXIT_FAILURE); + } + seen_cache = true; + if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) { + error_report("Invalid cache mode `%s'", optarg); + exit(EXIT_FAILURE); + } + break; + case QEMU_VU_OPT_AIO: + if (seen_aio) { + error_report("--aio can only be specified once"); + exit(EXIT_FAILURE); + } + seen_aio = true; + if (!strcmp(optarg, "native")) { + flags |= BDRV_O_NATIVE_AIO; + } else if (!strcmp(optarg, "threads")) { + /* this is the default */ + } else { + error_report("invalid aio mode `%s'", optarg); + exit(EXIT_FAILURE); + } + break; + case 'r': + readonly = true; + flags &= ~BDRV_O_RDWR; + break; + case 'k': + sockpath = optarg; + if (sockpath[0] != '/') { + error_report("socket path must be absolute"); + exit(EXIT_FAILURE); + } + break; + case 'f': + fmt = optarg; + break; + case 'V': + version(argv[0]); + exit(0); + break; + case 'h': + usage(argv[0]); + exit(0); + break; + case '?': + error_report("Try `%s --help' for more information.", argv[0]); + exit(EXIT_FAILURE); + } + } + + if ((argc - optind) != 1) { + error_report("Invalid number of arguments"); + error_printf("Try `%s --help' for more information.\n", argv[0]); + exit(EXIT_FAILURE); + } + + if (qemu_init_main_loop(&local_err)) { + error_report_err(local_err); + exit(EXIT_FAILURE); + } + bdrv_init(); + + srcpath = argv[optind]; + if (fmt) { + options = qdict_new(); + qdict_put_str(options, "driver", fmt); + } + blk = blk_new_open(srcpath, NULL, options, flags, &local_err); + + if (!blk) { + error_reportf_err(local_err, "Failed to blk_new_open '%s': ", + argv[optind]); + exit(EXIT_FAILURE); + } + bs = blk_bs(blk); + + blk_set_enable_write_cache(blk, !writethrough); + + fd_size = blk_getlength(blk); + if (fd_size < 0) { + error_report("Failed to determine the image length: %s", + strerror(-fd_size)); + exit(EXIT_FAILURE); + } + + AioContext *ctx = bdrv_get_aio_context(bs); + bdrv_invalidate_cache(bs, NULL); + + vub_device = g_new0(VubDev, 1); + vub_device->unix_socket = g_strdup(sockpath); + vub_device->writable = !readonly; + vub_device->blkcfg.wce = !writethrough; + vub_device->backend = blk; + vub_device->ctx = ctx; + vub_initialize_config(bs, &vub_device->blkcfg); + vub_device->listener = qio_net_listener_new(); + vub_device->exit_panic = exit_panic; + + qio_net_listener_set_name(vub_device->listener, + "vhost-user-backend-listener"); + + SocketAddress *addr = g_new0(SocketAddress, 1); + addr->u.q_unix.path = (char *) sockpath; + addr->type = SOCKET_ADDRESS_TYPE_UNIX; + Error **errp = NULL; + if (qio_net_listener_open_sync(vub_device->listener, addr, 1, errp) < 0) { + goto error; + } + + qio_net_listener_set_client_func(vub_device->listener, + vub_accept, + vub_device, + NULL); + + QTAILQ_INIT(&vub_device->clients); + + do { + main_loop_wait(false); + } while (!vub_device->exit_panic || !vub_device->close); + + error: + vus_shutdown(); + exit(EXIT_SUCCESS); +} -- 2.24.1
