Re: [PATCH v2 07/12] vfio/platform: Use vfio_[attach/detach]_device

[Eric Auger]

Hi,

On 9/26/23 13:32, Zhenzhong Duan wrote:
> From: Eric Auger <eric.auger@redhat.com>
>
> Let the vfio-platform device use vfio_attach_device() and
> vfio_detach_device(), hence hiding the details of the used
> IOMMU backend.
>
> Drop the trace event for vfio-platform as we have similar
> one in vfio_attach_device.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>  hw/vfio/platform.c   | 43 +++----------------------------------------
>  hw/vfio/trace-events |  1 -
>  2 files changed, 3 insertions(+), 41 deletions(-)
>
> diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
> index 5af73f9287..8e3d4ac458 100644
> --- a/hw/vfio/platform.c
> +++ b/hw/vfio/platform.c
> @@ -529,12 +529,7 @@ static VFIODeviceOps vfio_platform_ops = {
>   */
>  static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp)
>  {
> -    VFIOGroup *group;
> -    VFIODevice *vbasedev_iter;
> -    char *tmp, group_path[PATH_MAX], *group_name;
> -    ssize_t len;
>      struct stat st;
> -    int groupid;
>      int ret;
>  
>      /* @sysfsdev takes precedence over @host */
> @@ -557,47 +552,15 @@ static int vfio_base_device_init(VFIODevice *vbasedev, 
> Error **errp)
>          return -errno;
>      }
>  
> -    tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
> -    len = readlink(tmp, group_path, sizeof(group_path));
> -    g_free(tmp);
> -
> -    if (len < 0 || len >= sizeof(group_path)) {
> -        ret = len < 0 ? -errno : -ENAMETOOLONG;
> -        error_setg_errno(errp, -ret, "no iommu_group found");
> -        return ret;
> -    }
> -
> -    group_path[len] = 0;
> -
> -    group_name = basename(group_path);
> -    if (sscanf(group_name, "%d", &groupid) != 1) {
> -        error_setg_errno(errp, errno, "failed to read %s", group_path);
> -        return -errno;
> -    }
> -
Here also on error path we are leaking both vbasedev->name and
vbasedev->sysfsdev. This is independent on this patch
care must be taken because vdev->vbasedev.name is used in the caller
(vfio_platform_realize) to output the error msg
deallocation could happen there?

Eric
> -    trace_vfio_platform_base_device_init(vbasedev->name, groupid);
> -
> -    group = vfio_get_group(groupid, &address_space_memory, errp);
> -    if (!group) {
> -        return -ENOENT;
> -    }
> -
> -    QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> -        if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
> -            error_setg(errp, "device is already attached");
> -            vfio_put_group(group);
> -            return -EBUSY;
> -        }
> -    }
> -    ret = vfio_get_device(group, vbasedev->name, vbasedev, errp);
> +    ret = vfio_attach_device(vbasedev->name, vbasedev,
> +                             &address_space_memory, errp);
>      if (ret) {
> -        vfio_put_group(group);
>          return ret;
>      }
>  
>      ret = vfio_populate_device(vbasedev, errp);
>      if (ret) {
> -        vfio_put_group(group);
> +        vfio_detach_device(vbasedev);
>      }
>  
>      return ret;
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index e710026a73..3ac914854b 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -120,7 +120,6 @@ vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t 
> size, uint64_t bitmap_size
>  vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) "iommu 
> dirty @ 0x%"PRIx64" - 0x%"PRIx64
>  
>  # platform.c
> -vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group 
> #%d"
>  vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
>  vfio_platform_eoi(int pin, int fd) "EOI IRQ pin %d (fd=%d)"
>  vfio_platform_intp_mmap_enable(int pin) "IRQ #%d still active, stay in slow 
> path"