Re: [Qemu-devel] [PATCH v8 1/2] block/vxhs.c: Add support for a new block device type called "vxhs"

[Jeff Cody]

On Wed, Feb 08, 2017 at 09:23:33PM -0800, Ashish Mittal wrote:
> From: Ashish Mittal <address@hidden>
> 
> Source code for the qnio library that this code loads can be downloaded from:
> https://github.com/VeritasHyperScale/libqnio.git
> 
> Sample command line using JSON syntax:
> ./x86_64-softmmu/qemu-system-x86_64 -name instance-00000008 -S -vnc 0.0.0.0:0
> -k en-us -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5
> -msg timestamp=on
> 'json:{"driver":"vxhs","vdisk-id":"c3e9095a-a5ee-4dce-afeb-2a59fb387410",
> "server":{"host":"172.172.17.4","port":"9999"}}'
> 
> Sample command line using URI syntax:
> qemu-img convert -f raw -O raw -n
> /var/lib/nova/instances/_base/0c5eacd5ebea5ed914b6a3e7b18f1ce734c386ad
> vxhs://192.168.0.1:9999/c6718f6b-0401-441d-a8c3-1f0064d75ee0
>

I don't know if I am using the qnio_server test server correctly or not, but
when I run qemu-io from the command line I get an i/o error.  When I run the
qemu-iotests, I get a segfault.

Were you able to run qemu-iotests with these patches?

Here is how I am invoking qnio_server:

# qnio_server  -d 
/home/jcody/work/redhat/upstream/qemu-kvm/tests/qemu-iotests/scratch -v



> Signed-off-by: Ashish Mittal <address@hidden>
> ---
> TODO:
> (1) valgrind report to follow soon.
> 
> v8 changelog:
> (1) Security implementation for libqnio present in branch 'securify'.
>     Please use 'securify' branch for building libqnio and testing
>     with this patch.
> (2) Renamed libqnio to libvxhs.
> (3) Pass instance ID to libvxhs for SSL authentication.
> 
> v7 changelog:
> (1) IO failover code has moved out to the libqnio library.
> (2) Fixes for issues reported by Stefan on v6.
> (3) Incorporated the QEMUBH patch provided by Stefan.
>     This is a replacement for the pipe mechanism used earlier.
> (4) Fixes to the buffer overflows reported in libqnio.
> (5) Input validations in vxhs.c to prevent any buffer overflows for 
>     arguments passed to libqnio.
> 
> v6 changelog:
> (1) Added qemu-iotests for VxHS as a new patch in the series.
> (2) Replaced release version from 2.8 to 2.9 in block-core.json.
> 
> v5 changelog:
> (1) Incorporated v4 review comments.
> 
> v4 changelog:
> (1) Incorporated v3 review comments on QAPI changes.
> (2) Added refcounting for device open/close.
>     Free library resources on last device close.
> 
> v3 changelog:
> (1) Added QAPI schema for the VxHS driver.
> 
> v2 changelog:
> (1) Changes done in response to v1 comments.
> 
>  block/Makefile.objs  |   2 +
>  block/trace-events   |  16 ++
>  block/vxhs.c         | 499 
> +++++++++++++++++++++++++++++++++++++++++++++++++++
>  configure            |  41 +++++
>  qapi/block-core.json |  20 ++-
>  5 files changed, 576 insertions(+), 2 deletions(-)
>  create mode 100644 block/vxhs.c
> 
> diff --git a/block/Makefile.objs b/block/Makefile.objs
> index c6bd14e..75675b4 100644
> --- a/block/Makefile.objs
> +++ b/block/Makefile.objs
> @@ -19,6 +19,7 @@ block-obj-$(CONFIG_LIBNFS) += nfs.o
>  block-obj-$(CONFIG_CURL) += curl.o
>  block-obj-$(CONFIG_RBD) += rbd.o
>  block-obj-$(CONFIG_GLUSTERFS) += gluster.o
> +block-obj-$(CONFIG_VXHS) += vxhs.o
>  block-obj-$(CONFIG_ARCHIPELAGO) += archipelago.o
>  block-obj-$(CONFIG_LIBSSH2) += ssh.o
>  block-obj-y += accounting.o dirty-bitmap.o
> @@ -39,6 +40,7 @@ rbd.o-cflags       := $(RBD_CFLAGS)
>  rbd.o-libs         := $(RBD_LIBS)
>  gluster.o-cflags   := $(GLUSTERFS_CFLAGS)
>  gluster.o-libs     := $(GLUSTERFS_LIBS)
> +vxhs.o-libs        := $(VXHS_LIBS)
>  ssh.o-cflags       := $(LIBSSH2_CFLAGS)
>  ssh.o-libs         := $(LIBSSH2_LIBS)
>  archipelago.o-libs := $(ARCHIPELAGO_LIBS)
> diff --git a/block/trace-events b/block/trace-events
> index 0bc5c0a..d5eca93 100644
> --- a/block/trace-events
> +++ b/block/trace-events
> @@ -110,3 +110,19 @@ qed_aio_write_data(void *s, void *acb, int ret, uint64_t 
> offset, size_t len) "s
>  qed_aio_write_prefill(void *s, void *acb, uint64_t start, size_t len, 
> uint64_t offset) "s %p acb %p start %"PRIu64" len %zu offset %"PRIu64
>  qed_aio_write_postfill(void *s, void *acb, uint64_t start, size_t len, 
> uint64_t offset) "s %p acb %p start %"PRIu64" len %zu offset %"PRIu64
>  qed_aio_write_main(void *s, void *acb, int ret, uint64_t offset, size_t len) 
> "s %p acb %p ret %d offset %"PRIu64" len %zu"
> +
> +# block/vxhs.c
> +vxhs_iio_callback(int error) "ctx is NULL: error %d"
> +vxhs_iio_callback_chnfail(int err, int error) "QNIO channel failed, no i/o 
> %d, %d"
> +vxhs_iio_callback_unknwn(int opcode, int err) "unexpected opcode %d, errno 
> %d"
> +vxhs_aio_rw_invalid(int req) "Invalid I/O request iodir %d"
> +vxhs_aio_rw_ioerr(char *guid, int iodir, uint64_t size, uint64_t off, void 
> *acb, int ret, int err) "IO ERROR (vDisk %s) FOR : Read/Write = %d size = %lu 
> offset = %lu ACB = %p. Error = %d, errno = %d"
> +vxhs_get_vdisk_stat_err(char *guid, int ret, int err) "vDisk (%s) stat ioctl 
> failed, ret = %d, errno = %d"
> +vxhs_get_vdisk_stat(char *vdisk_guid, uint64_t vdisk_size) "vDisk %s stat 
> ioctl returned size %lu"
> +vxhs_qnio_iio_open(const char *ip) "Failed to connect to storage agent on 
> host-ip %s"
> +vxhs_complete_aio(void *acb, uint64_t ret) "aio failed acb %p ret %ld"
> +vxhs_parse_uri_filename(const char *filename) "URI passed via 
> bdrv_parse_filename %s"
> +vxhs_qemu_init_vdisk(const char *vdisk_id) "vdisk-id from json %s"
> +vxhs_parse_uri_hostinfo(int num, char *host, int port) "Host %d: IP %s, Port 
> %d"
> +vxhs_qemu_init(char *of_vsa_addr, int port) "Adding host %s:%d to 
> BDRVVXHSState"
> +vxhs_close(char *vdisk_guid) "Closing vdisk %s"
> diff --git a/block/vxhs.c b/block/vxhs.c
> new file mode 100644
> index 0000000..f1b5f1c
> --- /dev/null
> +++ b/block/vxhs.c
> @@ -0,0 +1,499 @@
> +/*
> + * QEMU Block driver for Veritas HyperScale (VxHS)
> + *
> + * 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 "qemu/osdep.h"
> +#include <qnio/qnio_api.h>
> +#include <sys/param.h>
> +#include "block/block_int.h"
> +#include "qapi/qmp/qerror.h"
> +#include "qapi/qmp/qdict.h"
> +#include "qapi/qmp/qstring.h"
> +#include "trace.h"
> +#include "qemu/uri.h"
> +#include "qapi/error.h"
> +#include "qemu/uuid.h"
> +
> +#define VXHS_OPT_FILENAME           "filename"
> +#define VXHS_OPT_VDISK_ID           "vdisk-id"
> +#define VXHS_OPT_SERVER             "server"
> +#define VXHS_OPT_HOST               "host"
> +#define VXHS_OPT_PORT               "port"
> +#define VXHS_UUID_DEF "12345678-1234-1234-1234-123456789012"

What is this?  It is not a valid UUID; is the value significant?

> +
> +QemuUUID qemu_uuid __attribute__ ((weak));

I have questions on this later, at [1]

> +
> +static int lib_init_failed;

With a ref count, I think this can go away.

> +
> +typedef enum {
> +    VDISK_AIO_READ,
> +    VDISK_AIO_WRITE,
> +} VDISKAIOCmd;
> +
> +/*
> + * HyperScale AIO callbacks structure
> + */
> +typedef struct VXHSAIOCB {
> +    BlockAIOCB common;
> +    int err;
> +    QEMUIOVector *qiov;
> +} VXHSAIOCB;
> +
> +typedef struct VXHSvDiskHostsInfo {
> +    void *dev_handle; /* Device handle */
> +    char *host; /* Host name or IP */
> +    int port; /* Host's port number */
> +} VXHSvDiskHostsInfo;
> +
> +/*
> + * Structure per vDisk maintained for state
> + */
> +typedef struct BDRVVXHSState {
> +    VXHSvDiskHostsInfo vdisk_hostinfo; /* Per host info */
> +    char *vdisk_guid;
> +} BDRVVXHSState;
> +
> +static void vxhs_complete_aio_bh(void *opaque)
> +{
> +    VXHSAIOCB *acb = opaque;
> +    BlockCompletionFunc *cb = acb->common.cb;
> +    void *cb_opaque = acb->common.opaque;
> +    int ret = 0;
> +
> +    if (acb->err != 0) {
> +        trace_vxhs_complete_aio(acb, acb->err);
> +        ret = (-EIO);
> +    }
> +
> +    qemu_aio_unref(acb);
> +    cb(cb_opaque, ret);
> +}
> +
> +/*
> + * Called from a libqnio thread
> + */
> +static void vxhs_iio_callback(void *ctx, uint32_t opcode, uint32_t error)
> +{
> +    VXHSAIOCB *acb = NULL;
> +
> +    switch (opcode) {
> +    case IRP_READ_REQUEST:
> +    case IRP_WRITE_REQUEST:
> +
> +        /*
> +         * ctx is VXHSAIOCB*
> +         * ctx is NULL if error is QNIOERROR_CHANNEL_HUP
> +         */
> +        if (ctx) {
> +            acb = ctx;
> +        } else {
> +            trace_vxhs_iio_callback(error);
> +            goto out;
> +        }
> +
> +        if (error) {
> +            if (!acb->err) {
> +                acb->err = error;
> +            }
> +            trace_vxhs_iio_callback(error);
> +        }
> +
> +        aio_bh_schedule_oneshot(bdrv_get_aio_context(acb->common.bs),
> +                                vxhs_complete_aio_bh, acb);
> +        break;
> +
> +    default:
> +        if (error == QNIOERROR_HUP) {
> +            /*
> +             * Channel failed, spontaneous notification,
> +             * not in response to I/O
> +             */
> +            trace_vxhs_iio_callback_chnfail(error, errno);
> +        } else {
> +            trace_vxhs_iio_callback_unknwn(opcode, error);
> +        }
> +        break;
> +    }
> +out:
> +    return;
> +}
> +
> +static QemuOptsList runtime_opts = {
> +    .name = "vxhs",
> +    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
> +    .desc = {
> +        {
> +            .name = VXHS_OPT_FILENAME,
> +            .type = QEMU_OPT_STRING,
> +            .help = "URI to the Veritas HyperScale image",
> +        },
> +        {
> +            .name = VXHS_OPT_VDISK_ID,
> +            .type = QEMU_OPT_STRING,
> +            .help = "UUID of the VxHS vdisk",
> +        },
> +        { /* end of list */ }
> +    },
> +};
> +
> +static QemuOptsList runtime_tcp_opts = {
> +    .name = "vxhs_tcp",
> +    .head = QTAILQ_HEAD_INITIALIZER(runtime_tcp_opts.head),
> +    .desc = {
> +        {
> +            .name = VXHS_OPT_HOST,
> +            .type = QEMU_OPT_STRING,
> +            .help = "host address (ipv4 addresses)",
> +        },
> +        {
> +            .name = VXHS_OPT_PORT,
> +            .type = QEMU_OPT_NUMBER,
> +            .help = "port number on which VxHSD is listening (default 9999)",
> +            .def_value_str = "9999"
> +        },
> +        { /* end of list */ }
> +    },
> +};
> +
> +/*
> + * Parse the incoming URI and populate *options with the host information.
> + * URI syntax has the limitation of supporting only one host info.
> + * To pass multiple host information, use the JSON syntax.
> + */
> +static int vxhs_parse_uri(const char *filename, QDict *options)
> +{
> +    URI *uri = NULL;
> +    char *hoststr, *portstr;
> +    char *port;
> +    int ret = 0;
> +
> +    trace_vxhs_parse_uri_filename(filename);
> +    uri = uri_parse(filename);
> +    if (!uri || !uri->server || !uri->path) {
> +        uri_free(uri);
> +        return -EINVAL;
> +    }
> +
> +    hoststr = g_strdup(VXHS_OPT_SERVER".host");
> +    qdict_put(options, hoststr, qstring_from_str(uri->server));
> +    g_free(hoststr);
> +
> +    portstr = g_strdup(VXHS_OPT_SERVER".port");
> +    if (uri->port) {
> +        port = g_strdup_printf("%d", uri->port);
> +        qdict_put(options, portstr, qstring_from_str(port));
> +        g_free(port);
> +    }
> +    g_free(portstr);
> +
> +    if (strstr(uri->path, "vxhs") == NULL) {
> +        qdict_put(options, "vdisk-id", qstring_from_str(uri->path));
> +    }
> +
> +    trace_vxhs_parse_uri_hostinfo(1, uri->server, uri->port);
> +    uri_free(uri);
> +
> +    return ret;
> +}
> +
> +static void vxhs_parse_filename(const char *filename, QDict *options,
> +                                Error **errp)
> +{
> +    if (qdict_haskey(options, "vdisk-id") || qdict_haskey(options, 
> "server")) {
> +        error_setg(errp, "vdisk-id/server and a file name may not be 
> specified "
> +                         "at the same time");
> +        return;
> +    }
> +
> +    if (strstr(filename, "://")) {
> +        int ret = vxhs_parse_uri(filename, options);
> +        if (ret < 0) {
> +            error_setg(errp, "Invalid URI. URI should be of the form "
> +                       "  vxhs://<host_ip>:<port>/<vdisk-id>");
> +        }
> +    }
> +}
> +
> +static int vxhs_open(BlockDriverState *bs, QDict *options,
> +                     int bdrv_flags, Error **errp)
> +{
> +    BDRVVXHSState *s = bs->opaque;
> +    void *dev_handlep = NULL;
> +    QDict *backing_options = NULL;
> +    QemuOpts *opts, *tcp_opts;
> +    char *of_vsa_addr = NULL;
> +    Error *local_err = NULL;
> +    const char *vdisk_id_opt;
> +    const char *server_host_opt;
> +    char *str = NULL;
> +    int ret = 0;
> +
> +    if (lib_init_failed) {
> +        return -ENODEV;
> +    }

Since you can't call iio_init() in the bdrv_vxhs_init() function [1],
instead of the above you can just use a refcnt, and call iio_init when the
refcnt is 0.


> +    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
> +    qemu_opts_absorb_qdict(opts, options, &local_err);
> +    if (local_err) {
> +        ret = -EINVAL;
> +        goto out;
> +    }
> +
> +    /* vdisk-id is the disk UUID */
> +    vdisk_id_opt = qemu_opt_get(opts, VXHS_OPT_VDISK_ID);
> +    if (!vdisk_id_opt) {
> +        error_setg(&local_err, QERR_MISSING_PARAMETER, VXHS_OPT_VDISK_ID);
> +        ret = -EINVAL;
> +        goto out;
> +    }
> +
> +    /* vdisk-id may contain a leading '/' */
> +    if (strlen(vdisk_id_opt) > UUID_FMT_LEN + 1) {
> +        error_setg(errp, "vdisk-id cannot be more than %d characters",

You are propagating local_err in the error handler "out:" via
error_propagate() for all the other cases, but setting errp directly here.
That will happen to work out, because local_err will be NULL and
error_propagate() will be a NOOP in that case, but it probably isn't what
you intended.  You should set &local_err, like in the other error cases.

> +                   UUID_FMT_LEN);
> +        ret = -EINVAL;
> +        goto out;
> +    }
> +
> +    s->vdisk_guid = g_strdup(vdisk_id_opt);
> +    trace_vxhs_qemu_init_vdisk(vdisk_id_opt);
> +
> +    str = g_strdup_printf(VXHS_OPT_SERVER".");
> +    qdict_extract_subqdict(options, &backing_options, str);
> +
> +    /* Create opts info from runtime_tcp_opts list */
> +    tcp_opts = qemu_opts_create(&runtime_tcp_opts, NULL, 0, &error_abort);
> +    qemu_opts_absorb_qdict(tcp_opts, backing_options, &local_err);
> +    if (local_err) {
> +        qdict_del(backing_options, str);
> +        qemu_opts_del(tcp_opts);
> +        ret = -EINVAL;
> +        goto out;
> +    }
> +
> +    server_host_opt = qemu_opt_get(tcp_opts, VXHS_OPT_HOST);
> +    if (!server_host_opt) {
> +        error_setg(&local_err, QERR_MISSING_PARAMETER,
> +                   VXHS_OPT_SERVER"."VXHS_OPT_HOST);
> +        ret = -EINVAL;
> +        goto out;
> +    }
> +
> +    if (strlen(server_host_opt) > MAXHOSTNAMELEN) {
> +        error_setg(errp, "server.host cannot be more than %d characters",
> +                   MAXHOSTNAMELEN);
> +        ret = -EINVAL;
> +        goto out;
> +    }
> +
> +    s->vdisk_hostinfo.host = g_strdup(server_host_opt);
> +
> +    s->vdisk_hostinfo.port = g_ascii_strtoll(qemu_opt_get(tcp_opts,
> +                                                          VXHS_OPT_PORT),
> +                                                          NULL, 0);
> +
> +    trace_vxhs_qemu_init(s->vdisk_hostinfo.host,
> +                         s->vdisk_hostinfo.port);
> +
> +    qdict_del(backing_options, str);
> +    qemu_opts_del(tcp_opts);
> +
> +    of_vsa_addr = g_strdup_printf("of://%s:%d",
> +                                s->vdisk_hostinfo.host,
> +                                s->vdisk_hostinfo.port);
> +
> +    /*
> +     * Open qnio channel to storage agent if not opened before.
> +     */
> +    dev_handlep = iio_open(of_vsa_addr, s->vdisk_guid, 0);
> +    if (dev_handlep == NULL) {
> +        trace_vxhs_qnio_iio_open(of_vsa_addr);
> +        ret = -ENODEV;
> +        goto out;
> +    }
> +    s->vdisk_hostinfo.dev_handle = dev_handlep;
> +
> +out:
> +    g_free(str);
> +    g_free(of_vsa_addr);
> +    QDECREF(backing_options);
> +    qemu_opts_del(opts);
> +
> +    if (ret < 0) {
> +        error_propagate(errp, local_err);
> +        g_free(s->vdisk_hostinfo.host);
> +        g_free(s->vdisk_guid);
> +        s->vdisk_guid = NULL;
> +        errno = -ret;
> +    }
> +
> +    return ret;
> +}
> +
> +static const AIOCBInfo vxhs_aiocb_info = {
> +    .aiocb_size = sizeof(VXHSAIOCB)
> +};
> +
> +/*
> + * This allocates QEMU-VXHS callback for each IO
> + * and is passed to QNIO. When QNIO completes the work,
> + * it will be passed back through the callback.
> + */
> +static BlockAIOCB *vxhs_aio_rw(BlockDriverState *bs, int64_t sector_num,
> +                               QEMUIOVector *qiov, int nb_sectors,
> +                               BlockCompletionFunc *cb, void *opaque,
> +                               VDISKAIOCmd iodir)
> +{
> +    VXHSAIOCB *acb = NULL;
> +    BDRVVXHSState *s = bs->opaque;
> +    size_t size;
> +    uint64_t offset;
> +    int iio_flags = 0;
> +    int ret = 0;
> +    void *dev_handle = s->vdisk_hostinfo.dev_handle;
> +
> +    offset = sector_num * BDRV_SECTOR_SIZE;
> +    size = nb_sectors * BDRV_SECTOR_SIZE;
> +    acb = qemu_aio_get(&vxhs_aiocb_info, bs, cb, opaque);
> +
> +    /*
> +     * Initialize VXHSAIOCB.
> +     */
> +    acb->err = 0;
> +    acb->qiov = qiov;
> +
> +    iio_flags = IIO_FLAG_ASYNC;
> +
> +    switch (iodir) {
> +    case VDISK_AIO_WRITE:
> +            ret = iio_writev(dev_handle, acb, qiov->iov, qiov->niov,
> +                             offset, (uint64_t)size, iio_flags);
> +            break;
> +    case VDISK_AIO_READ:
> +            ret = iio_readv(dev_handle, acb, qiov->iov, qiov->niov,
> +                            offset, (uint64_t)size, iio_flags);
> +            break;
> +    default:
> +            trace_vxhs_aio_rw_invalid(iodir);
> +            goto errout;
> +    }
> +
> +    if (ret != 0) {
> +        trace_vxhs_aio_rw_ioerr(s->vdisk_guid, iodir, size, offset,
> +                                acb, ret, errno);
> +        goto errout;
> +    }
> +    return &acb->common;
> +
> +errout:
> +    qemu_aio_unref(acb);
> +    return NULL;
> +}
> +
> +static BlockAIOCB *vxhs_aio_readv(BlockDriverState *bs,
> +                                   int64_t sector_num, QEMUIOVector *qiov,
> +                                   int nb_sectors,
> +                                   BlockCompletionFunc *cb, void *opaque)
> +{
> +    return vxhs_aio_rw(bs, sector_num, qiov, nb_sectors, cb,
> +                       opaque, VDISK_AIO_READ);
> +}
> +
> +static BlockAIOCB *vxhs_aio_writev(BlockDriverState *bs,
> +                                   int64_t sector_num, QEMUIOVector *qiov,
> +                                   int nb_sectors,
> +                                   BlockCompletionFunc *cb, void *opaque)
> +{
> +    return vxhs_aio_rw(bs, sector_num, qiov, nb_sectors,
> +                       cb, opaque, VDISK_AIO_WRITE);
> +}
> +
> +static void vxhs_close(BlockDriverState *bs)
> +{
> +    BDRVVXHSState *s = bs->opaque;
> +
> +    trace_vxhs_close(s->vdisk_guid);
> +
> +    g_free(s->vdisk_guid);
> +    s->vdisk_guid = NULL;
> +
> +    /*
> +     * Close vDisk device
> +     */
> +    if (s->vdisk_hostinfo.dev_handle) {
> +        iio_close(s->vdisk_hostinfo.dev_handle);
> +        s->vdisk_hostinfo.dev_handle = NULL;
> +    }
> +
> +    /*
> +     * Free the dynamically allocated host string
> +     */
> +    g_free(s->vdisk_hostinfo.host);
> +    s->vdisk_hostinfo.host = NULL;
> +    s->vdisk_hostinfo.port = 0;

If you use a static vxhs iio refcnt, you can decrement it here and call
iio_fini (which is now currently never called) to free resources.


> +}
> +
> +static int64_t vxhs_get_vdisk_stat(BDRVVXHSState *s)
> +{
> +    int64_t vdisk_size = -1;
> +    int ret = 0;
> +    void *dev_handle = s->vdisk_hostinfo.dev_handle;
> +
> +    ret = iio_ioctl(dev_handle, IOR_VDISK_STAT, &vdisk_size, 0);
> +    if (ret < 0) {
> +        trace_vxhs_get_vdisk_stat_err(s->vdisk_guid, ret, errno);
> +        return -EIO;
> +    }
> +
> +    trace_vxhs_get_vdisk_stat(s->vdisk_guid, vdisk_size);
> +    return vdisk_size;
> +}
> +
> +/*
> + * Returns the size of vDisk in bytes. This is required
> + * by QEMU block upper block layer so that it is visible
> + * to guest.
> + */
> +static int64_t vxhs_getlength(BlockDriverState *bs)
> +{
> +    BDRVVXHSState *s = bs->opaque;
> +    int64_t vdisk_size;
> +
> +    vdisk_size = vxhs_get_vdisk_stat(s);
> +    if (vdisk_size < 0) {
> +        return -EIO;
> +    }
> +
> +    return vdisk_size;
> +}
> +
> +static BlockDriver bdrv_vxhs = {
> +    .format_name                  = "vxhs",
> +    .protocol_name                = "vxhs",
> +    .instance_size                = sizeof(BDRVVXHSState),
> +    .bdrv_file_open               = vxhs_open,
> +    .bdrv_parse_filename          = vxhs_parse_filename,
> +    .bdrv_close                   = vxhs_close,
> +    .bdrv_getlength               = vxhs_getlength,
> +    .bdrv_aio_readv               = vxhs_aio_readv,
> +    .bdrv_aio_writev              = vxhs_aio_writev,
> +};
> +
> +static void bdrv_vxhs_init(void)
> +{
> +    char out[37];
> +
> +    if (qemu_uuid_is_null(&qemu_uuid)) {
> +        lib_init_failed = iio_init(QNIO_VERSION, vxhs_iio_callback, 
> VXHS_UUID_DEF);
> +    } else {
> +        qemu_uuid_unparse(&qemu_uuid, out);
> +        lib_init_failed = iio_init(QNIO_VERSION, vxhs_iio_callback, out);
> +    }
> +

[1]

Can you explain what is going on here with the qemu_uuid check?


You also can't do this here.  This init function is just to register the
driver (e.g. populate the BlockDriver list).  You shouldn't be doing
anything other than the bdrv_register() call here.

Since you want to run this iio_init only once, I would recommend doing it in
the vxhs_open() call, and using a ref counter.  That way, you can also call
iio_fini() to finish releasing resources once the last device is closed.

This was actually a suggestion I had before, which you then incorporated
into v6, but it appears all the refcnt code has gone away for v7/v8.


> +    bdrv_register(&bdrv_vxhs);
> +}
> +
> +block_init(bdrv_vxhs_init);
> diff --git a/configure b/configure
> index 6325339..c3ccf02 100755
> --- a/configure
> +++ b/configure
> @@ -321,6 +321,7 @@ numa=""
>  tcmalloc="no"
>  jemalloc="no"
>  replication="yes"
> +vxhs=""
>  
>  # parse CC options first
>  for opt do
> @@ -1170,6 +1171,10 @@ for opt do
>    ;;
>    --enable-replication) replication="yes"
>    ;;
> +  --disable-vxhs) vxhs="no"
> +  ;;
> +  --enable-vxhs) vxhs="yes"
> +  ;;
>    *)
>        echo "ERROR: unknown option $opt"
>        echo "Try '$0 --help' for more information"
> @@ -1403,6 +1408,7 @@ disabled with --disable-FEATURE, default is enabled if 
> available:
>    tcmalloc        tcmalloc support
>    jemalloc        jemalloc support
>    replication     replication support
> +  vxhs            Veritas HyperScale vDisk backend support
>  
>  NOTE: The object files are built at the place where configure is launched
>  EOF
> @@ -4748,6 +4754,34 @@ if test "$modules" = "yes" && test "$LD_REL_FLAGS" = 
> ""; then
>  fi
>  
>  ##########################################
> +# Veritas HyperScale block driver VxHS
> +# Check if libvxhs is installed
> +
> +if test "$vxhs" != "no" ; then
> +  cat > $TMPC <<EOF
> +#include <stdint.h>
> +#include <qnio/qnio_api.h>
> +
> +#define VXHS_UUID "12345678-1234-1234-1234-123456789012"
> +void *vxhs_callback;
> +
> +int main(void) {
> +    iio_init(QNIO_VERSION, vxhs_callback, VXHS_UUID);
> +    return 0;
> +}
> +EOF
> +  vxhs_libs="-lvxhs -lssl"
> +  if compile_prog "" "$vxhs_libs" ; then
> +    vxhs=yes
> +  else
> +    if test "$vxhs" = "yes" ; then
> +      feature_not_found "vxhs block device" "Install libvxhs See github"
> +    fi
> +    vxhs=no
> +  fi
> +fi
> +
> +##########################################
>  # End of CC checks
>  # After here, no more $cc or $ld runs
>  
> @@ -5114,6 +5148,7 @@ echo "tcmalloc support  $tcmalloc"
>  echo "jemalloc support  $jemalloc"
>  echo "avx2 optimization $avx2_opt"
>  echo "replication support $replication"
> +echo "VxHS block device $vxhs"
>  
>  if test "$sdl_too_old" = "yes"; then
>  echo "-> Your SDL version is too old - please upgrade to have SDL support"
> @@ -5729,6 +5764,12 @@ if test "$pthread_setname_np" = "yes" ; then
>    echo "CONFIG_PTHREAD_SETNAME_NP=y" >> $config_host_mak
>  fi
>  
> +if test "$vxhs" = "yes" ; then
> +  echo "CONFIG_VXHS=y" >> $config_host_mak
> +  echo "VXHS_CFLAGS=$vxhs_cflags" >> $config_host_mak
> +  echo "VXHS_LIBS=$vxhs_libs" >> $config_host_mak
> +fi
> +
>  if test "$tcg_interpreter" = "yes"; then
>    QEMU_INCLUDES="-I\$(SRC_PATH)/tcg/tci $QEMU_INCLUDES"
>  elif test "$ARCH" = "sparc64" ; then
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 932f5bb..f37df56 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -2110,6 +2110,7 @@
>  # @nfs: Since 2.8
>  # @replication: Since 2.8
>  # @ssh: Since 2.8
> +# @vxhs: Since 2.9
>  #
>  # Since: 2.0
>  ##
> @@ -2119,7 +2120,7 @@
>              'host_device', 'http', 'https', 'luks', 'nbd', 'nfs', 'null-aio',
>              'null-co', 'parallels', 'qcow', 'qcow2', 'qed', 'quorum', 'raw',
>              'replication', 'ssh', 'vdi', 'vhdx', 'vmdk', 'vpc',
> -            'vvfat' ] }
> +            'vvfat','vxhs' ] }
>  
>  ##
>  # @BlockdevOptionsFile:
> @@ -2744,6 +2745,20 @@
>    'data': { '*offset': 'int', '*size': 'int' } }
>  
>  ##
> +# @BlockdevOptionsVxHS:
> +#
> +# Driver specific block device options for VxHS
> +#
> +# @vdisk-id:    UUID of VxHS volume
> +# @server:      vxhs server IP, port
> +#
> +# Since: 2.9
> +##
> +{ 'struct': 'BlockdevOptionsVxHS',
> +  'data': { 'vdisk-id': 'str',
> +            'server': 'InetSocketAddress' } }
> +
> +##
>  # @BlockdevOptions:
>  #
>  # Options for creating a block device.  Many options are available for all
> @@ -2806,7 +2821,8 @@
>        'vhdx':       'BlockdevOptionsGenericFormat',
>        'vmdk':       'BlockdevOptionsGenericCOWFormat',
>        'vpc':        'BlockdevOptionsGenericFormat',
> -      'vvfat':      'BlockdevOptionsVVFAT'
> +      'vvfat':      'BlockdevOptionsVVFAT',
> +      'vxhs':       'BlockdevOptionsVxHS'
>    } }
>  
>  ##
> -- 
> 1.8.3.1
>