On Fri, Mar 02, 2018 at 02:26:48PM -0800, Siwei Liu wrote: > On Fri, Mar 2, 2018 at 1:31 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > > On Fri, Mar 02, 2018 at 12:44:56PM -0800, Siwei Liu wrote: > >> On Fri, Mar 2, 2018 at 12:10 PM, Michael S. Tsirkin <m...@redhat.com> > >> wrote: > >> > On Fri, Mar 02, 2018 at 11:52:27AM -0800, Samudrala, Sridhar wrote: > >> >> > >> >> > >> >> On 3/2/2018 11:41 AM, Michael S. Tsirkin wrote: > >> >> > On Fri, Mar 02, 2018 at 07:26:25AM -0800, Alexander Duyck wrote: > >> >> > > The design limits things to a 1:1 relationship since we just have > >> >> > > the > >> >> > > child and backup pointers, but I don't think I am seeing exception > >> >> > > handling to prevent us from overwriting the child pointers so there > >> >> > > may be a leak there. > >> >> > > > >> >> > > Thanks. > >> >> > > > >> >> > > - Alex > >> >> > In fact maintaining a list in that case would be nicer, and > >> >> > just use an arbitrary one. > >> >> > E.g. one can see how a user wanting to swap device 1 for device 2 > >> >> > might first add device 2 with same MAC then drop device 1. > >> >> > >> >> It should be possible to swap VF1 with VF2 by > >> >> 1.- enabling virtio link > >> >> 2.- unplugging VF1 > >> >> 3.- plugging VF2 > >> >> 4.- disabling virtio link > >> >> > >> > > >> > True, but it isn't hard to avoid breakage if user > >> > swapped steps 2 and 3. No need to make it more > >> > fragile that it has to be. > >> > >> The migration case, VF2 is associated with another PF on another > >> machine (destination), I wonder how it is possible. > > > > E.g. you want to remove the PF so you unplug the VF > > then add another VF of the same PF. > > > >> Even with local plugging of VF2 on the same PF, the MAC address > >> requirement (VF1's == VF2's) would fail the MAC address assignment on > >> VF2. > >> > >> -Siwei > > > > Why would it fail? These are separate cards. > > OK. I realized that you may talk about assigning a VF on a diffferent > PF (VF1 on PF1 while VF2 on PF2). And we might assign a pass-through > device rather than a VF. Yes, it's indeed possible that may happen but > I take it as a further step down (another patch maybe) as it would > involve changes to notify the network with gratuituious ARP and/or > unsolicited ND advertisement of the MAC address association with the > new port. > > -Siwei
Interesting point. I guess that's a limitation in the curent patch then: virtio and PT device must be connected to the same physical NIC. Worth documenting. > > > >> > > >> > -- > >> > MST > >> > > >> > --------------------------------------------------------------------- > >> > To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org > >> > For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org > >> > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
