Re: [PATCH v3 4/5] a standone-alone tool to directly share disk image file via vhost-user protocol

[Coiby Xu]

I forgot to put backends/vhost-user-blk-server.o as dependency for
qemu-vu target in Makefile,

 qemu-img$(EXESUF): qemu-img.o $(authz-obj-y) $(block-obj-y)
$(crypto-obj-y) $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
 qemu-nbd$(EXESUF): qemu-nbd.o $(authz-obj-y) $(block-obj-y)
$(crypto-obj-y) $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
+
+ifdef CONFIG_LINUX
+qemu-vu$(EXESUF): qemu-vu.o backends/vhost-user-blk-server.o
$(authz-obj-y) $(block-obj-y) $(crypto-obj-y) $(io-obj-y) $(qom-obj-y)
$(COMMON_LDADDS) libvhost-user.a
+endif
 qemu-io$(EXESUF): qemu-io.o $(authz-obj-y) $(block-obj-y)
$(crypto-obj-y) $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)

I also noticed in the latest version of QEMU, `make check-qtest`
somehow doesn't run qos-test. If you need to run vhost-user-blk
testsuite, please execute the following command after applying the
above fix and the 5th patch,

  MALLOC_PERTURB_=${MALLOC_PERTURB_:-$(( ${RANDOM:-0} % 255 + 1))}
QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64
QTEST_QEMU_IMG=./qemu-img QTEST_QEMU_VU_BINARY=./qemu-vu
tests/qos-test -m=quick -k --tap < /dev/null | ./scripts/tap-driver.pl
--test-name="qos-test"


On Wed, Feb 12, 2020 at 5:52 PM Coiby Xu <address@hidden> wrote:
>
> vhost-user-blk could 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).
>
> In the future Kevin's qemu-storage-daemon will be used to replace this
> tool.
>
> Signed-off-by: Coiby Xu <address@hidden>
> ---
>  Makefile  |   4 +
>  configure |   3 +
>  qemu-vu.c | 252 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 259 insertions(+)
>  create mode 100644 qemu-vu.c
>
> diff --git a/Makefile b/Makefile
> index f0e1a2fc1d..0bfd2f1ddd 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -572,6 +572,10 @@ qemu-img.o: qemu-img-cmds.h
>
>  qemu-img$(EXESUF): qemu-img.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y) 
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
>  qemu-nbd$(EXESUF): qemu-nbd.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y) 
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
> +
> +ifdef CONFIG_LINUX
> +qemu-vu$(EXESUF): qemu-vu.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y) 
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS) libvhost-user.a
> +endif
>  qemu-io$(EXESUF): qemu-io.o $(authz-obj-y) $(block-obj-y) $(crypto-obj-y) 
> $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
>
>  qemu-bridge-helper$(EXESUF): qemu-bridge-helper.o $(COMMON_LDADDS)
> diff --git a/configure b/configure
> index 115dc38085..e87c9a5587 100755
> --- a/configure
> +++ b/configure
> @@ -6217,6 +6217,9 @@ if test "$want_tools" = "yes" ; then
>    if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" ] ; then
>      tools="qemu-nbd\$(EXESUF) $tools"
>    fi
> +  if [ "$linux" = "yes" ] ; then
> +    tools="qemu-vu\$(EXESUF) $tools"
> +  fi
>    if [ "$ivshmem" = "yes" ]; then
>      tools="ivshmem-client\$(EXESUF) ivshmem-server\$(EXESUF) $tools"
>    fi
> diff --git a/qemu-vu.c b/qemu-vu.c
> new file mode 100644
> index 0000000000..dd1032b205
> --- /dev/null
> +++ b/qemu-vu.c
> @@ -0,0 +1,252 @@
> +/*
> + *  Copyright (C) 2020  Coiby Xu <address@hidden>
> + *
> + *  standone-alone vhost-user-blk device server 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 "backends/vhost-user-blk-server.h"
> +#include "block/block_int.h"
> +#include "io/net-listener.h"
> +#include "qapi/error.h"
> +#include "qapi/qmp/qdict.h"
> +#include "qapi/qmp/qstring.h"
> +#include "qemu/config-file.h"
> +#include "qemu/cutils.h"
> +#include "qemu/main-loop.h"
> +#include "qemu/module.h"
> +#include "qemu/option.h"
> +#include "qemu-common.h"
> +#include "qemu-version.h"
> +#include "qom/object_interfaces.h"
> +#include "sysemu/block-backend.h"
> +#define QEMU_VU_OPT_CACHE         256
> +#define QEMU_VU_OPT_AIO           257
> +#define QEMU_VU_OBJ_ID   "vu_disk"
> +static QemuOptsList qemu_object_opts = {
> +    .name = "object",
> +    .implied_opt_name = "qom-type",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
> +    .desc = {
> +        { }
> +    },
> +};
> +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 VuBlockDev *vu_block_device;
> +
> +static void vus_shutdown(void)
> +{
> +
> +    Error *local_err = NULL;
> +    job_cancel_sync_all();
> +    bdrv_close_all();
> +    user_creatable_del(QEMU_VU_OBJ_ID, &local_err);
> +}
> +
> +int main(int argc, char **argv)
> +{
> +    BlockBackend *blk;
> +    BlockDriverState *bs;
> +    bool readonly = false;
> +    char *sockpath = NULL;
> +    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_when_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_when_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);
> +
> +    char buf[300];
> +    snprintf(buf, 300, "%s,id=%s,node-name=%s,unix-socket=%s,writable=%s",
> +             TYPE_VHOST_USER_BLK_SERVER, QEMU_VU_OBJ_ID, 
> bdrv_get_node_name(bs),
> +             sockpath, !readonly ? "on" : "off");
> +    /* While calling user_creatable_del, 'object' group is required */
> +    qemu_add_opts(&qemu_object_opts);
> +    QemuOpts *opts = qemu_opts_parse(&qemu_object_opts, buf, true, 
> &local_err);
> +    if (local_err) {
> +        error_report_err(local_err);
> +        goto error;
> +    }
> +
> +    Object *obj = user_creatable_add_opts(opts, &local_err);
> +
> +    if (local_err) {
> +        error_report_err(local_err);
> +        goto error;
> +    }
> +
> +    vu_block_device = VHOST_USER_BLK_SERVER(obj);
> +    vu_block_device->exit_when_panic = exit_when_panic;
> +
> +    do {
> +        main_loop_wait(false);
> +    } while (!vu_block_device->exit_when_panic || 
> !vu_block_device->vu_server->close);
> +
> + error:
> +    vus_shutdown();
> +    exit(EXIT_SUCCESS);
> +}
> --
> 2.25.0
>


--
Best regards,
Coiby