Re: [libvirt] [Qemu-devel] [PATCH 2/3] scsi-disk: Add device_id property

Am 28.01.2019 um 17:55 hat Markus Armbruster geschrieben: > Kevin Wolf <kwolf(a)redhat.com&gt; writes: > > > Am 28.01.2019 um 09:50 hat Peter Krempa geschrieben: > [...] > >> 2) Is actually using 'scsi-cd'/'scsi-hd' the better option than > >> 'scsi-disk'? > > > > Yes, scsi-disk is a legacy device. Maybe we should formally deprecate > > it. > > There's an internal use in scsi_bus_legacy_add_drive(), which in turn > powers two legacy features: > > 1. -drive if=scsi > > Creates scsi-disk frontends. > > Only works with onboard HBAs since commit 14545097267, v2.12.0. > > 2. -device usb-storage > > Bad magic: usb-storage pretends to be a block device, but it's really > a SCSI bus that can serve only a single device, which it creates > automatically. > > If we deprecate scsi-disk, we should deprecate these, too. Can't say > whether that's practical right now. Most likely not worth the effort anyway. I don't think it's blocking anything.

> >> 3) Since upstream libvirt supports qemu-1.5 and newer and 'scsi-cd' is > >> already supported there, can we assume that all newer versions support > >> it? (Basically the question is whether it can be compiled out by > >> upstream means). > > > > I think so. > > Compiling out scsi-hd or scsi-cd, but not scsi-disk would be silly. All > three devices are in scsi-disk.c. You'd have to hack that up to be > silly. I understood this as a question about libvirt, i.e. whether libvirt can drop/compile out their scsi-disk code and instead assume that scsi-hd/cd are always present. Maybe I misunderstood, though?