On Mon, 7 Aug 2017 17:52:04 -0400 "taii...@gmx.com" <taii...@gmx.com> wrote:
> I want to add physical serial ports to a VM but I can't find any FLR > supporting serial cards (I have looked at spec sheets for the chips no luck) > > Ideally there would be a multi port card (say 4 or so) where every port > can be separately assigned. > > Anyone have any info? - Thanks I think you're headed in the wrong direction, serial ports and PCI device assignment can be done, but it's not a great match. For starters, serial ports don't do DMA, so the whole IOMMU thing is a bit overkill. You're also not likely to find a serial ASIC designed within the last 20yrs, so things like ACS and FLR are mostly out of the question, besides the device state of a serial port is pretty minimal and a device specific reset could probably be made to handle it, but I'm not sure it's even necessary. Performance is also likely to be not much, if any, better than just serial passthrough because the register set of a serial device doesn't fill a 4K page or may be implemented as I/O port rather than MMIO, so you'll probably trap to QEMU for every access anyway unless you can get 4k alignment on the MMIO BARs. USB serial passthrough might be a better option, but FLR seems exceptionally unlikely. Thanks, Alex _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
