[dpdk-dev] [RFC 01/19] vhost: protect virtio_net device struct

[Maxime Coquelin]

On 07/05/2017 12:07 PM, Jens Freimann wrote:
> On Tue, Jul 04, 2017 at 11:49:04AM +0200, Maxime Coquelin wrote:
>> virtio_net device might be accessed while being reallocated
>> in case of NUMA awareness. This case might be theoretical,
>> but it will be needed anyway to protect vrings pages against
>> invalidation.
>>
>> The virtio_net devs are now protected with a readers/writers
>> lock, so that before reallocating the device, it is ensured
>> that it is not being referenced by the processing threads.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
>> ---
>> lib/librte_vhost/vhost.c      | 223 
>> +++++++++++++++++++++++++++++++++++-------
>> lib/librte_vhost/vhost.h      |   3 +-
>> lib/librte_vhost/vhost_user.c |  73 +++++---------
>> lib/librte_vhost/virtio_net.c |  17 +++-
>> 4 files changed, 228 insertions(+), 88 deletions(-)
> [...]
>> +int
>> +realloc_device(int vid, int vq_index, int node)
>> +{
>> +    struct virtio_net *dev, *old_dev;
>> +    struct vhost_virtqueue *vq;
>> +
>> +    dev = rte_malloc_socket(NULL, sizeof(*dev), 0, node);
>> +    if (!dev)
>> +        return -1;
>> +
>> +    vq = rte_malloc_socket(NULL, sizeof(*vq), 0, node);
>> +    if (!vq)
>> +        return -1;
>> +
>> +    old_dev = get_device_wr(vid);
>> +    if (!old_dev)
>> +        return -1;
> 
> Should we free vq and dev here?

Of course we should.
This will be fixed in next release.

Thanks,
Maxime