Re: [Qemu-devel] [PATCH v3 4/5] qga: report disk serial number

[Marc-André Lureau]

Hi

On Fri, Sep 7, 2018 at 3:42 PM Tomáš Golembiovský <address@hidden> wrote:
>
> The feature is implemented for Windows and Linux. Reporting of serial
> number on Linux depends on libudev.
>
> Example from Linux:
>
>     {
>       "name": "dm-2",
>       "mountpoint": "/",
>       ...
>       "disk": [
>         {
>           "serial": "SAMSUNG_MZ7LN512HCHP-000L1_S1ZKNXAG822493",
>           ...
>         }
>       ],
>     }
>
> Signed-off-by: Tomáš Golembiovský <address@hidden>
> ---
>  configure            | 22 ++++++++++++++
>  qga/Makefile.objs    |  1 +
>  qga/commands-posix.c | 22 ++++++++++++++
>  qga/commands-win32.c | 71 ++++++++++++++++++++++++++++++++------------
>  qga/qapi-schema.json |  4 ++-

looks good overall,

This patch could easily be splitted in 3 or 4 patches.

You should check the build without udev.

>  5 files changed, 100 insertions(+), 20 deletions(-)
>
> diff --git a/configure b/configure
> index 0f168607e8..ac24cb3975 100755
> --- a/configure
> +++ b/configure
> @@ -477,6 +477,7 @@ libxml2=""
>  docker="no"
>  debug_mutex="no"
>  libpmem=""
> +libudev="no"
>
>  # cross compilers defaults, can be overridden with --cross-cc-ARCH
>  cross_cc_aarch64="aarch64-linux-gnu-gcc"
> @@ -873,6 +874,7 @@ Linux)
>    vhost_vsock="yes"
>    QEMU_INCLUDES="-I\$(SRC_PATH)/linux-headers -I$(pwd)/linux-headers 
> $QEMU_INCLUDES"
>    supported_os="yes"
> +  libudev="yes"
>  ;;
>  esac
>
> @@ -5676,6 +5678,20 @@ if test "$libnfs" != "no" ; then
>    fi
>  fi
>
> +##########################################
> +# Do we have libudev
> +if test "$libudev" != "no" ; then
> +  if $pkg_config libudev; then
> +    libudev="yes"
> +    libudev_libs=$($pkg_config --libs libudev)
> +  else
> +    if test "$libudev" = "yes" ; then
> +      feature_not_found "libudev" "Install systemd development files"
> +    fi
> +    libudev="no"
> +  fi
> +fi
> +
>  # Now we've finished running tests it's OK to add -Werror to the compiler 
> flags
>  if test "$werror" = "yes"; then
>      QEMU_CFLAGS="-Werror $QEMU_CFLAGS"
> @@ -6100,6 +6116,7 @@ echo "VxHS block device $vxhs"
>  echo "capstone          $capstone"
>  echo "docker            $docker"
>  echo "libpmem support   $libpmem"
> +echo "libudev           $libudev"
>
>  if test "$sdl_too_old" = "yes"; then
>  echo "-> Your SDL version is too old - please upgrade to have SDL support"
> @@ -6944,6 +6961,11 @@ if test "$docker" != "no"; then
>      echo "HAVE_USER_DOCKER=y" >> $config_host_mak
>  fi
>
> +if test "$libudev" != "no"; then
> +    echo "CONFIG_LIBUDEV=y" >> $config_host_mak
> +    echo "LIBUDEV_LIBS=$libudev_libs" >> $config_host_mak
> +fi
> +
>  # use included Linux headers
>  if test "$linux" = "yes" ; then
>    mkdir -p linux-headers
> diff --git a/qga/Makefile.objs b/qga/Makefile.objs
> index ed08c5917c..80e6bb3c2e 100644
> --- a/qga/Makefile.objs
> +++ b/qga/Makefile.objs
> @@ -1,3 +1,4 @@
> +commands-posix.o-libs := $(LIBUDEV_LIBS)
>  qga-obj-y = commands.o guest-agent-command-state.o main.o
>  qga-obj-$(CONFIG_POSIX) += commands-posix.o channel-posix.o
>  qga-obj-$(CONFIG_WIN32) += commands-win32.o channel-win32.o service-win32.o
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 37e8a2d791..37fedd123b 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -47,6 +47,7 @@ extern char **environ;
>  #include <sys/socket.h>
>  #include <net/if.h>
>  #include <sys/statvfs.h>
> +#include <libudev.h>
>

#ifdef CONFIG_LIBUDEV

>  #ifdef FIFREEZE
>  #define CONFIG_FSFREEZE
> @@ -872,6 +873,10 @@ static void build_guest_fsinfo_for_real_device(char 
> const *syspath,
>      GuestDiskAddressList *list = NULL;
>      bool has_ata = false, has_host = false, has_tgt = false;
>      char *p, *q, *driver = NULL;
> +#ifdef CONFIG_LIBUDEV
> +    struct udev *udev = NULL;
> +    struct udev_device *udevice = NULL;
> +#endif
>
>      p = strstr(syspath, "/devices/pci");
>      if (!p || sscanf(p + 12, "%*x:%*x/%x:%x:%x.%x%n",
> @@ -936,6 +941,21 @@ static void build_guest_fsinfo_for_real_device(char 
> const *syspath,
>      list = g_malloc0(sizeof(*list));
>      list->value = disk;
>
> +#ifdef CONFIG_LIBUDEV
> +    udev = udev_new();
> +    udevice = udev_device_new_from_syspath(udev, syspath);
> +    if (udev == NULL || udevice == NULL) {
> +        g_debug("failed to query udev");
> +    } else {
> +        const char *serial;
> +        serial = udev_device_get_property_value(udevice, "ID_SERIAL");
> +        if (serial != NULL && *serial != 0) {
> +            disk->serial = g_strdup(serial);
> +            disk->has_serial = true;
> +        }
> +    }
> +#endif
> +
>      if (strcmp(driver, "ata_piix") == 0) {
>          /* a host per ide bus, target*:0:<unit>:0 */
>          if (!has_host || !has_tgt) {
> @@ -1003,6 +1023,8 @@ cleanup:
>          qapi_free_GuestDiskAddressList(list);
>      }
>      g_free(driver);
> +    udev_unref(udev);
> +    udev_device_unref(udevice);

#ifdef CONFIG_LIBUDEV

It might be more convenient/nicer to create a seperate udev helper
file to fill the entry?

>  }
>
>  static void build_guest_fsinfo_for_device(char const *devpath,
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index e16c58275e..fa186154a8 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -583,25 +583,53 @@ out:
>      return pci;
>  }
>
> -static int get_disk_bus_type(HANDLE vol_h, Error **errp)
> +static void get_disk_properties(HANDLE vol_h, GuestDiskAddress *disk,
> +    Error **errp)
>  {
>      STORAGE_PROPERTY_QUERY query;
>      STORAGE_DEVICE_DESCRIPTOR *dev_desc, buf;
>      DWORD received;
> +    ULONG size = sizeof(buf);
>
>      dev_desc = &buf;
> -    dev_desc->Size = sizeof(buf);
>      query.PropertyId = StorageDeviceProperty;
>      query.QueryType = PropertyStandardQuery;
>
>      if (!DeviceIoControl(vol_h, IOCTL_STORAGE_QUERY_PROPERTY, &query,
>                           sizeof(STORAGE_PROPERTY_QUERY), dev_desc,
> -                         dev_desc->Size, &received, NULL)) {
> +                         size, &received, NULL)) {
>          error_setg_win32(errp, GetLastError(), "failed to get bus type");
> -        return -1;
> +        return;
> +    }
> +    disk->bus_type = find_bus_type(dev_desc->BusType);
> +    g_debug("bus type %d", disk->bus_type);
> +
> +    /* Query once more. Now with long enough buffer. */
> +    size = dev_desc->Size;
> +    dev_desc = g_malloc0(size);
> +    if (!DeviceIoControl(vol_h, IOCTL_STORAGE_QUERY_PROPERTY, &query,
> +                         sizeof(STORAGE_PROPERTY_QUERY), dev_desc,
> +                         size, &received, NULL)) {
> +        error_setg_win32(errp, GetLastError(), "failed to get serial 
> number");
> +        goto out_free;
> +    }
> +    if (dev_desc->SerialNumberOffset > 0) {
> +        if (dev_desc->SerialNumberOffset >= received) {
> +            error_setg(errp, "offset outside the buffer");
> +            goto out_free;
> +        }
> +        const char *serial = (char *)dev_desc + dev_desc->SerialNumberOffset;
> +        size_t len = received - dev_desc->SerialNumberOffset;
> +        if (*serial != 0) {
> +            disk->serial = g_strndup(serial, len);

This may overallocate a bit. Not a big deal.

> +            disk->has_serial = true;
> +            g_debug("serial number %s", disk->serial);
> +        }
>      }
> +out_free:
> +    g_free(dev_desc);
>
> -    return dev_desc->BusType;
> +    return;
>  }
>
>  /* VSS provider works with volumes, thus there is no difference if
> @@ -613,8 +641,8 @@ static GuestDiskAddressList *build_guest_disk_info(char 
> *guid, Error **errp)
>      GuestDiskAddress *disk;
>      SCSI_ADDRESS addr, *scsi_ad;
>      DWORD len;
> -    int bus;
>      HANDLE vol_h;
> +    Error *local_err = NULL;
>
>      scsi_ad = &addr;
>      char *name = g_strndup(guid, strlen(guid)-1);
> @@ -624,22 +652,22 @@ static GuestDiskAddressList *build_guest_disk_info(char 
> *guid, Error **errp)
>                         0, NULL);
>      if (vol_h == INVALID_HANDLE_VALUE) {
>          error_setg_win32(errp, GetLastError(), "failed to open volume");
> -        goto out_free;
> +        goto err;
>      }
>
> -    g_debug("getting bus type");
> -    bus = get_disk_bus_type(vol_h, errp);
> -    if (bus < 0) {
> -        goto out_close;
> +    disk = g_malloc0(sizeof(*disk));
> +    get_disk_properties(vol_h, disk, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        goto err_close;
>      }
>
> -    disk = g_malloc0(sizeof(*disk));
> -    disk->bus_type = find_bus_type(bus);
> -    g_debug("bus type %d", disk->bus_type);
> -    if (bus == BusTypeScsi || bus == BusTypeAta || bus == BusTypeRAID
> +    if (disk->bus_type == GUEST_DISK_BUS_TYPE_SCSI
> +            || disk->bus_type == GUEST_DISK_BUS_TYPE_IDE
> +            || disk->bus_type == GUEST_DISK_BUS_TYPE_RAID
>  #if (_WIN32_WINNT >= 0x0600)
>              /* This bus type is not supported before Windows Server 2003 SP1 
> */
> -            || bus == BusTypeSas
> +            || disk->bus_type == GUEST_DISK_BUS_TYPE_SAS
>  #endif
>          ) {
>          /* We are able to use the same ioctls for different bus types
> @@ -679,11 +707,16 @@ static GuestDiskAddressList *build_guest_disk_info(char 
> *guid, Error **errp)
>      list = g_malloc0(sizeof(*list));
>      list->value = disk;
>      list->next = NULL;
> -out_close:
>      CloseHandle(vol_h);
> -out_free:
> -    g_free(name);
>      return list;
> +
> +err_close:
> +    g_free(disk);
> +    CloseHandle(vol_h);
> +err:
> +    g_free(name);
> +
> +    return NULL;
>  }
>
>  #else
> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> index dfbc4a5e32..3bcda6257e 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -834,13 +834,15 @@
>  # @bus: bus id
>  # @target: target id
>  # @unit: unit id
> +# @serial: serial number (since: 3.1)
>  #
>  # Since: 2.2
>  ##
>  { 'struct': 'GuestDiskAddress',
>    'data': {'pci-controller': 'GuestPCIAddress',
>             'bus-type': 'GuestDiskBusType',
> -           'bus': 'int', 'target': 'int', 'unit': 'int'} }
> +           'bus': 'int', 'target': 'int', 'unit': 'int',
> +           '*serial': 'str'} }
>
>  ##
>  # @GuestFilesystemInfo:
> --
> 2.18.0
>