Re: [PATCH v2 05/12] vfio/common: Extract out vfio_kvm_device_[add/del]_fd

[Eric Auger <eric.auger@redhat.com>]

Hi Zhenzhong,

On 9/26/23 13:32, Zhenzhong Duan wrote:
> Introduce two new helpers, vfio_kvm_device_[add/del]_fd
> which take as input a file descriptor which can be either a group fd or
> a cdev fd. This uses the new KVM_DEV_VFIO_FILE VFIO KVM device group,
> which aliases to the legacy KVM_DEV_VFIO_GROUP.
>
> vfio_kvm_device_[add/del]_group then call those new helpers.
>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>  include/hw/vfio/vfio-common.h |  3 ++
>  hw/vfio/common.c              | 55 +++++++++++++++++++++++++----------
>  2 files changed, 42 insertions(+), 16 deletions(-)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index e0483893d1..c4e7c3b4a7 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -226,6 +226,9 @@ struct vfio_device_info *vfio_get_device_info(int fd);
>  int vfio_get_device(VFIOGroup *group, const char *name,
>                      VFIODevice *vbasedev, Error **errp);
>  
> +int vfio_kvm_device_add_fd(int fd, Error **errp);
> +int vfio_kvm_device_del_fd(int fd, Error **errp);
> +
>  extern const MemoryRegionOps vfio_region_ops;
>  typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList;
>  extern VFIOGroupList vfio_group_list;
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index de6b4a86e2..959b1362bb 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1818,17 +1818,17 @@ void vfio_reset_handler(void *opaque)
>      }
>  }
>  
> -static void vfio_kvm_device_add_group(VFIOGroup *group)
> +int vfio_kvm_device_add_fd(int fd, Error **errp)
>  {
>  #ifdef CONFIG_KVM
>      struct kvm_device_attr attr = {
> -        .group = KVM_DEV_VFIO_GROUP,
> -        .attr = KVM_DEV_VFIO_GROUP_ADD,
> -        .addr = (uint64_t)(unsigned long)&group->fd,
> +        .group = KVM_DEV_VFIO_FILE,
> +        .attr = KVM_DEV_VFIO_FILE_ADD,
> +        .addr = (uint64_t)(unsigned long)&fd,
>      };
>  
>      if (!kvm_enabled()) {
> -        return;
> +        return 0;
>      }
>  
>      if (vfio_kvm_device_fd < 0) {
> @@ -1837,38 +1837,61 @@ static void vfio_kvm_device_add_group(VFIOGroup *group)
>          };
>  
>          if (kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd)) {
> -            error_report("Failed to create KVM VFIO device: %m");
> -            return;
> +            error_setg_errno(errp, errno, "Failed to create KVM VFIO device");
> +            return -errno;
>          }
>  
>          vfio_kvm_device_fd = cd.fd;
>      }
>  
>      if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) {
> -        error_report("Failed to add group %d to KVM VFIO device: %m",
> -                     group->groupid);
> +        error_setg_errno(errp, errno, "Failed to add fd %d to KVM VFIO device",
> +                         fd);
> +        return -errno;
>      }
>  #endif
> +    return 0;
>  }
>  
> -static void vfio_kvm_device_del_group(VFIOGroup *group)
> +int vfio_kvm_device_del_fd(int fd, Error **errp)
>  {
>  #ifdef CONFIG_KVM
>      struct kvm_device_attr attr = {
> -        .group = KVM_DEV_VFIO_GROUP,
> -        .attr = KVM_DEV_VFIO_GROUP_DEL,
> -        .addr = (uint64_t)(unsigned long)&group->fd,
> +        .group = KVM_DEV_VFIO_FILE,
> +        .attr = KVM_DEV_VFIO_FILE_DEL,
> +        .addr = (uint64_t)(unsigned long)&fd,
>      };
>  
>      if (vfio_kvm_device_fd < 0) {
> -        return;
> +        error_setg(errp, "KVM VFIO device isn't created yet");
> +        return -EINVAL;
>      }
>  
>      if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) {
> -        error_report("Failed to remove group %d from KVM VFIO device: %m",
> -                     group->groupid);
> +        error_setg_errno(errp, errno,
> +                         "Failed to remove fd %d from KVM VFIO device", fd);
> +        return -errno;
>      }
>  #endif
> +    return 0;
> +}
> +
> +static void vfio_kvm_device_add_group(VFIOGroup *group)
> +{
> +    Error *err = NULL;
> +
> +    if (vfio_kvm_device_add_fd(group->fd, &err)) {
> +        error_reportf_err(err, "group ID %d: ", group->groupid);
> +    }
> +}
> +
> +static void vfio_kvm_device_del_group(VFIOGroup *group)
> +{
> +    Error *err = NULL;
> +
> +    if (vfio_kvm_device_del_fd(group->fd, &err)) {
> +        error_reportf_err(err, "group ID %d: ", group->groupid);
> +    }
>  }
>  
>  static VFIOAddressSpace *vfio_get_address_space(AddressSpace *as)
Looks good to me
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric