Pawel Moll <pawel.moll@xxxxxxx> writes: > On Fri, 2015-02-13 at 02:52 +0000, Rusty Russell wrote: >> "Michael S. Tsirkin" <mst@xxxxxxxxxx> writes: >> > On Tue, Feb 10, 2015 at 12:02:37PM +1030, Rusty Russell wrote: >> >> Jason Wang <jasowang@xxxxxxxxxx> writes: >> >> > This patch enables the interrupt coalescing setting through ethtool. >> >> >> >> The problem is that there's nothing network specific about interrupt >> >> coalescing. I can see other devices wanting exactly the same thing, >> >> which means we'd deprecate this in the next virtio standard. >> >> >> >> I think the right answer is to extend like we did with >> >> vring_used_event(), eg: >> >> >> >> 1) Add a new feature VIRTIO_F_RING_COALESCE. >> >> 2) Add another a 32-bit field after vring_used_event(), eg: >> >> #define vring_used_delay(vr) (*(u32 *)((vr)->avail->ring[(vr)->num + 2])) >> >> >> >> This loses the ability to coalesce by number of frames, but we can still >> >> do number of sg entries, as we do now with used_event, and we could >> >> change virtqueue_enable_cb_delayed() to take a precise number if we >> >> wanted. >> > >> > But do we expect delay to be update dynamically? >> > If not, why not stick it in config space? >> >> Hmm, we could update it dynamically (and will, in the case of ethtool). >> But it won't be common, so we could append a field to >> virtio_pci_common_cfg for PCI. >> >> I think MMIO and CCW would be easy to extend too, but CC'd to check. > > As far as I understand the virtio_pci_common_cfg principle (just had a > look, for the first time ;-), it's now an equivalent of the MMIO control > registers block. I see no major problem with adding another one. OK, thanks. > Or were you thinking about introducing some standard for the "real" > config space? (fine with me as well - the transport will have nothing to > do :-) No, that'd not be possible at this point. I think it's a per-transport decision. Cheers, Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
