Re: [dpdk-dev] [PATCH 14/15] net/virtio: add vDPA op to get notification area

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 9/3/19 7:02 AM, Tiwei Bie wrote:
> On Thu, Aug 29, 2019 at 09:59:59AM +0200, Maxime Coquelin wrote:
>> This patch implements the vDPA .get_notify_area()
>> callback.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>>  drivers/net/virtio/virtio_vdpa.c | 33 ++++++++++++++++++++++++++++++++
>>  1 file changed, 33 insertions(+)
>>
>> diff --git a/drivers/net/virtio/virtio_vdpa.c b/drivers/net/virtio/virtio_vdpa.c
>> index e0b2f99ba..e681f527a 100644
>> --- a/drivers/net/virtio/virtio_vdpa.c
>> +++ b/drivers/net/virtio/virtio_vdpa.c
>> @@ -707,6 +707,38 @@ virtio_vdpa_get_vfio_device_fd(int vid)
>>  	return list->dev->vfio_dev_fd;
>>  }
>>  
>> +static int
>> +virtio_vdpa_get_notify_area(int vid, int qid, uint64_t *offset, uint64_t *size)
>> +{
>> +	int did;
>> +	struct internal_list *list;
>> +	struct virtio_vdpa_device *dev;
>> +	struct vfio_region_info reg = { .argsz = sizeof(reg) };
>> +	int ret;
>> +
>> +	did = rte_vhost_get_vdpa_device_id(vid);
>> +	list = find_internal_resource_by_did(did);
>> +	if (list == NULL) {
>> +		DRV_LOG(ERR, "Invalid device id: %d", did);
>> +		return -1;
>> +	}
>> +
>> +	dev = list->dev;
>> +
>> +	reg.index = dev->hw.notify_region;
>> +	ret = ioctl(dev->vfio_dev_fd, VFIO_DEVICE_GET_REGION_INFO, &reg);
>> +	if (ret) {
>> +		DRV_LOG(ERR, "Get not get device region info: %s",
>> +				strerror(errno));
>> +		return -1;
>> +	}
>> +
>> +	*offset = dev->vqs[qid].notify_addr - dev->hw.notify_base + reg.offset;
>> +	*size = 0x1000;
> 
> It would be better to check whether the size is no less
> than 0x1000, otherwise it's possible to give guest the
> access to other registers of the vdpa device.

Correct, if offset is not page-aligned, then it would mean one page may
be mapped while not needed. I took the ifcvf driver as example and
forgot to fix it. (Maybe it should also be fixed in ifcvf driver?)

Thanks,
Maxime
> Regards,
> Tiwei
> 
>> +
>> +	return 0;
>> +}
>> +
>>  static struct rte_vdpa_dev_ops virtio_vdpa_ops = {
>>  	.get_queue_num = virtio_vdpa_get_queue_num,
>>  	.get_features = virtio_vdpa_get_features,
>> @@ -716,6 +748,7 @@ static struct rte_vdpa_dev_ops virtio_vdpa_ops = {
>>  	.set_features = virtio_vdpa_set_features,
>>  	.get_vfio_group_fd = virtio_vdpa_get_vfio_group_fd,
>>  	.get_vfio_device_fd = virtio_vdpa_get_vfio_device_fd,
>> +	.get_notify_area = virtio_vdpa_get_notify_area,
>>  };
>>  
>>  static inline int
>> -- 
>> 2.21.0
>>