On Tue, 2 Jun 2026 17:50:04 +0100 Matt Evans <[email protected]> wrote: > On 29/05/2026 00:14, Alex Williamson wrote: > > On Wed, 27 May 2026 03:23:12 -0700 > > Matt Evans <[email protected]> wrote: > >> + uint32_t old_attr = priv->memattr; > >> + > >> + if (flags & VFIO_DEVICE_FEATURE_SET) { > >> + switch(db_attr.memattr) { > >> + case VFIO_DEVICE_FEATURE_DMA_BUF_MEMATTR_NC: > >> + case VFIO_DEVICE_FEATURE_DMA_BUF_MEMATTR_WC: > >> + priv->memattr = db_attr.memattr; > >> + break; > >> + > >> + default: > >> + ret = -ENOTSUPP; > > > > -EINVAL > > I'd like to push back on this one; ENOTSUPP distinguishes trying to use > a wild attribute value from all manner of other screwups such as > trying to GET (with it no longer supported), passing an fd that isn't a > DMABUF, etc. > > I'm not wed to the value ENOTSUPP, just something distinctive versus the > other errors userspace might see, and that value seems appropriate.
It needs to be a uAPI errno though, aiui ENOTSUPP is an internal NFS errno. How about EOPNOTSUPP? Thanks, Alex
