On 06/26/2014 11:25 AM, Alexander Graf wrote: > > On 26.06.14 10:53, Eric Auger wrote: >> On 06/25/2014 11:30 PM, Alexander Graf wrote: >>> On 02.06.14 09:49, Eric Auger wrote: >>>> This patch aims at allowing the end-user to specify the device he >>>> wants to directly assign to his mach-virt guest in the QEMU command >>>> line. >>>> >>>> The QEMU platform device becomes generic. >>>> >>>> Current choice is to reuse the "-device" option. >>>> >>>> For example when assigning Calxeda Midway xgmac device this option >>>> is used: >>>> -device vfio-platform,vfio_device="fff51000.ethernet",\ >>>> compat="calxeda/hb-xgmac",mmap-timeout-ms=1000 >>> I think we're walking into the right direction, but there is one major >>> nit I have. I don't think we should have a -device vfio-platform. I >>> think we should have a -device vfio-xgmac that maybe inherits from an >>> abstrace vfio-platform class. >>> >>> That way machine code can assemble the device tree according to the >>> device and you can also implement hardware specific hacks or >>> dependencies if you need them - for example the MMIO masking to find an >>> EOI you did earlier. >> I must admit I am lacking experience of other devices than my dear >> xgmac. I can just say that for the time beeing the approach seems to fit >> some ARM Amba devices like PL330 DMA. We need to go further to identity >> the limits of this generic approach. > > No, I think we're better off not faking anything generic at all, because > I'm 99.9% sure it will never be generic in real-world device cases. > > And if we start doing things generically, people will soon want to have > other mad additions to do device specific things in generic code, such > as "take the device tree from the host, but modify property x, y and z". > Better be clear about our limits from the beginning :). > > Imagine vfio-platform as a transport, similar to TCP. We have ports and > moving data from left to right is always the same, but whether you need > to open 2 ports to get a working FTP data transfer is up to the > implementation of the protocol above. Same thing here. OK you convinced me. I will investigate that way then. Eric > > > Alex > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
