On Fri, Mar 21, 2025 at 12:45 AM Konstantin Shkolnyy <k...@linux.ibm.com> wrote: > > On 3/19/2025 19:58, Jason Wang wrote: > > On Thu, Mar 20, 2025 at 12:34 AM Konstantin Shkolnyy <k...@linux.ibm.com> > > wrote: > >> Upon reading this forum, I see that VHOST_VDPA_SET_CONFIG is > >> “deprecated”, and so VIRTIO_NET_CTRL_MAC_ADDR_SET must be the right > >> method, but it’s apparently called too late. > > > > VHOST_VDPA_SET_CONFIG requires the vDPA parent support which is not > > necessarily there. > > The mlx5 driver doesn't do anything for VHOST_VDPA_SET_CONFIG. Intel's > driver, however, apparently stores the configuration. So, it appears, > Intel will avoid the problem... Perhaps mlx5 could do the same so that > QEMU can set the address before it starts the VM (QEMU doesn't have to > later let the VM change the config).
The problem is that config space is not allowed to be written, that is why mlx5 doesn't implement the write method. > Conceptually, setting the address > by QEMU cmdline doesn't look different from setting it by "vdpa dev add". It's kind of different. E.g the device may not even have VIRTIO_NET_F_MAC feature etc. Thanks >
