Re: [UNIKRAFT PATCH v4 00/12] Introduce Xen Netfront driver

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Hi Costin,

really, thanks a lot for picking up this patch series and driving it for 
upstreaming! This is great news. Lets make 2020 a lucky year for 
netfront ;-). I add a few comments inline to some patches that I briefly 
checked (I did a non-detailed review).
Please also consider the outstanding update to the Ethernet macro 
definitons in lib/uknetdev: https://patchwork.unikraft.org/patch/738013/ 
. Since Intel DPDK and in general NFV is one of our targets, we should 
support VLAN tags. This has an effect to the maximum transmission unit 
(1522 B). Do you know if your netfront driver can handle such frame 
sizes (more or less) out-of-the box? As far as I understood, we have 
some restrictions with our virtio driver currently and need to re-visit 
this.
Thanks,

Simon

On 13.08.20 10:53, Costin Lupu wrote:
> The current changes are required for supporting netfront devices. They should
> be used together with the lwip patch series because they depend on each other.
>
> These changes follow the same approach used for the design and implementation
> of the virtio-net driver.
>
> The first version of these patches was sent in 2018. Maybe the current year is
> a lucky one and we will achieve the performance to upstream these changes.
>
> Changes since v1:
> - Split into multiple patches
> - Use the new uknetdev API
>
> Changes since v2:
> - Add more info to commit messages
>
> Changes since v3:
> - Use nb_align field for queue infos
> - Add patch for enabling default drivers
>
> Costin Lupu (12):
>    plat/drivers/virtio: Fill MTU and queues alignments when retrieving
>      information
>    plat/xen: Add vif device type
>    plat/xen/drivers: Add skeleton for netfront driver
>    plat/xen/drivers/net: Configure netfront device
>    plat/xen/drivers/net: Create netfront queues
>    plat/xen/drivers/net: Configure netfront tx queue
>    plat/xen/drivers/net: Configure netfront rx queue
>    plat/xen/drivers/net: Enable/disable interrupts for rx queues
>    plat/xen/drivers/net: Start netfront device
>    plat/xen/drivers/net: Add transmit operation
>    plat/xen/drivers/net: Add receive operation
>    lib/uknetdev: Enable default drivers
>
>   lib/uknetdev/Config.uk             |   2 +
>   plat/drivers/virtio/virtio_net.c   |   3 +
>   plat/xen/Config.uk                 |   7 +
>   plat/xen/Makefile.uk               |  11 +
>   plat/xen/drivers/net/exportsyms.uk |   1 +
>   plat/xen/drivers/net/netfront.c    | 843 +++++++++++++++++++++++++++++
>   plat/xen/drivers/net/netfront.h    | 145 +++++
>   plat/xen/drivers/net/netfront_xb.h |  46 ++
>   plat/xen/drivers/net/netfront_xs.c | 522 ++++++++++++++++++
>   plat/xen/include/xenbus/xenbus.h   |   1 +
>   plat/xen/xenbus/client.c           |   1 +
>   11 files changed, 1582 insertions(+)
>   create mode 100644 plat/xen/drivers/net/exportsyms.uk
>   create mode 100644 plat/xen/drivers/net/netfront.c
>   create mode 100644 plat/xen/drivers/net/netfront.h
>   create mode 100644 plat/xen/drivers/net/netfront_xb.h
>   create mode 100644 plat/xen/drivers/net/netfront_xs.c