Re: [libvirt] [PATCH] RFC: bhyve: implement PCI address allocation

On 04/13/2014 08:53 AM, Roman Bogorodskiy wrote: Rather than doing a cut/paste of the qemu code, it would be greatly more desirable to move the pci address allocation from qemu into a library that is accessible from both drivers. This will eliminate dual maintenance headaches in the future. Projects like this can tend to be painful, but in the end it means that when someone using qemu finds and fixes a bug, it will automatically be fixed for bhyve. And. for example, when the qemu driver adds support for PCIe "root-port" controllers and upstream/downstream switches[*], the bhyve driver will automatically get address allocation support for those controllers too (if/when it implements the controllers). Or is there some particular reason that makes it better to keep it separate (or maybe some other conversation that I missed, or have forgotten)? [*]For reference, here is a description of the various PCI controller types - the design in this email is fairly close to what was eventually implemented, except that the actual code uses a "model" attribute to the controller element, rather than a separate <model> subelement: https://www.redhat.com/archives/libvir-list/2013-April/msg01144.html (root-port, upstream-switch-port, and downstream-switch-port weren't implemented at the time, because they weren't immediately useful) No. Slot 0 on each PCI controller is considered to be reserved, and doesn't show up in the domain definition. The address allocation code takes that into account. We don't model the ISA bus for qemu, and also don't support adding any device to the ISA bus (although qemu has one). I think you can just directly define a serial character device with port='0': <serial type='pty'> <target port='0'/> </serial>