> -----Original Message----- > From: Henry Gessau [mailto:ges...@cisco.com] > Sent: Tuesday, October 29, 2013 2:23 PM > To: OpenStack Development Mailing List (not for usage questions) > Subject: Re: [openstack-dev] [nova] [neutron] PCI pass-through network > support > > On Tue, Oct 29, at 4:31 pm, Jiang, Yunhong <yunhong.ji...@intel.com> > wrote: > > > Henry,why do you think the "service VM" need the entire PF instead of a > > VF? I think the SR-IOV NIC should provide QoS and performance > isolation. > > I was speculating. I just thought it might be a good idea to leave open the > possibility of assigning a PF to a VM if the need arises. > > Neutron service VMs are a new thing. I will be following the discussions > and > there is a summit session for them. It remains to be seen if there is any > desire/need for full PF ownership of NICs. But if a service VM owns the PF > and has the right NIC driver it could do some advanced features with it. > At least in current PCI implementation, if a device has no SR-IOV enabled, then that device will be exposed and can be assigned (is this your so-called PF?). If a device has SR-IOV enabled, then only VF be exposed and the PF is hidden from resource tracker. The reason is, when SR-IOV enabled, the PF is mostly used to configure and management the VFs, and it will be security issue to expose the PF to a guest.
I'm not sure if you are talking about the PF, are you talking about the PF w/ or w/o SR-IOV enabled. I totally agree that assign a PCI NIC to service VM have a lot of benefit from both performance and isolation point of view. Thanks --jyh _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
