Re: [PATCH v3 0/3] vdpa: Return -EIO if device ack is VIRTIO_NET_ERR

[Lei Yang]

Hello Hawkins

QE can help test this series before  it is merged into master, I would
like to know what test steps can cover this series related scenario?

Thanks
Lei

On Tue, Jul 4, 2023 at 11:36 AM Hawkins Jiawei <yin31149@gmail.com> wrote:
>
> According to VirtIO standard, "The class, command and
> command-specific-data are set by the driver,
> and the device sets the ack byte.
> There is little it can do except issue a diagnostic
> if ack is not VIRTIO_NET_OK."
>
> Therefore, QEMU should stop sending the queued SVQ commands and
> cancel the device startup if the device's ack is not VIRTIO_NET_OK.
>
> Yet the problem is that, vhost_vdpa_net_load_x() returns 1 based on
> `*s->status != VIRTIO_NET_OK` when the device's ack is VIRTIO_NET_ERR.
> As a result, net->nc->info->load() also returns 1, this makes
> vhost_net_start_one() incorrectly assume the device state is
> successfully loaded by vhost_vdpa_net_load() and return 0, instead of
> goto `fail` label to cancel the device startup, as vhost_net_start_one()
> only cancels the device startup when net->nc->info->load() returns a
> negative value.
>
> This patchset fixes this problem by returning -EIO when the device's
> ack is not VIRTIO_NET_OK.
>
> Changelog
> =========
> v3:
>  - split the fixes suggested by Eugenio
>  - return -EIO suggested by Michael
>
> v2: 
> https://lore.kernel.org/all/69010e9ebb5e3729aef595ed92840f43e48e53e5.1687875592.git.yin31149@gmail.com/
>  - fix the same bug in vhost_vdpa_net_load_offloads()
>
> v1: https://lore.kernel.org/all/cover.1686746406.git.yin31149@gmail.com/
>
> Hawkins Jiawei (3):
>   vdpa: Return -EIO if device ack is VIRTIO_NET_ERR in _load_mac()
>   vdpa: Return -EIO if device ack is VIRTIO_NET_ERR in _load_mq()
>   vdpa: Return -EIO if device ack is VIRTIO_NET_ERR in _load_offloads()
>
>  net/vhost-vdpa.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
>
> --
> 2.25.1
>
>