Re: [PATCH] virtio-net : Add check for VIRTIO_NET_F_MAC

[Michael S. Tsirkin]

On Wed, Sep 29, 2021 at 08:08:40PM +0800, Cindy Lu wrote:
> On Wed, Sep 29, 2021 at 6:07 PM Michael Tokarev <mjt@tls.msk.ru> wrote:
> >
> > 29.09.2021 09:52, Cindy Lu wrote:
> > > For vdpa device, if the host support VIRTIO_NET_F_MAC
> > > we need to read the mac address from hardware, so need
> > > to check this bit, the logic is
> > > 1 if the host support VIRTIO_NET_F_MAC and the mac address
> > >     is correct, qemu will use the mac address in hardware
> > > 2.if the host not support , qemu will use the mac from cmdline
> >
> > So if hw supports NET_F_MAC, cmdline-provided parameter will
> > silently be ignored?
> >
> yes, this is based on the virtio spec, you can check this document in
> 5.1.5 Device Initialization
> https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html

Maybe use the hw mac if mac is not provided? If provided
make sure the command line matches the hardware, and fail
otherwise?

> Also, this check it only working for vdpa device
> > s/host not support/host does not support this feature/
> Thanks , will fix this
> >
> > > 3.if the cmdline not provide mac address, qemu will use radam mac
> > > address
> >
> > s/not/does not/
> > s/radam/random/
> >
> thanks, will fix this
> > Thanks,
> >
> > /mjt
> >