On 7/29/2014 18:20, Michael Brown wrote:
I'm please to announce that iPXE now natively supports Xen netfront virtual NICs. This may be of interest to anyone wanting to use iPXE running in a Xen PV-HVM domain.
Awesome! :)
I have one issue which I'm not sure how to handle, and would appreciate feedback from anyone who frequently uses Xen: For each configured NIC, Xen exposes both an emulated PCI NIC (for OSes with no native Xen drivers) and a netfront virtual NIC (for OSes with native Xen drivers). Xen provides a mechanism for OSes to "unplug" the emulated PCI NICs. Operating systems with native Xen drivers will typically unplug the emulated PCI NICs to prevent confusion. iPXE could easily unplug the emulated PCI NICs. However, this operation is irreversible. If the loaded OS does not include native Xen drivers, then it will not be able to see any network devices. This is undesirable.
Personally, I don't think seeing both NICs is a huge deal, as a Xen user should be aware of the dual-NIC thing.
But: are there any ordering guarantees about which NIC of the pair is going to be first (net0) in iPXE?
Also: Would the unplugging happen before any NIC-detection, if it were going to happen? If so, that wouldn't suggest a 'xen-unplug' command, at least.
Maybe it could just sit as a build option and those who desire the guaranteed unplugging can build such. That seems to be the special scenario; better confused with the possibility of poorer performance with the emulated NIC than NICless at OS time, perhaps.
+$0.02 - Shao Miller _______________________________________________ ipxe-devel mailing list [email protected] https://lists.ipxe.org/mailman/listinfo.cgi/ipxe-devel
