On Wed, 2011-11-09 at 10:20 +0000, Sasha Levin wrote: > > > I'm also wondering it it's ok to move virtio configuration out of virtio > > > space and into PCI space for archs that don't have PCI (such as ARM).
Just a note - ARM-based chips can by all means have PCI (grep -r PCI arch/arm/ ;-). The fact is that most of the SOCs available on the market don't have it, but this is slowly changing. The main architectural difference is that ARM doesn't provide separate I/O space so the PCI I/O space is usually remapped somewhere into normal address space (grep -r "#define __io_address" arch/arm/) > > > Would it mean they get stuck with legacy configuration (and no new > > > features)? Or is there an alternative for them? > > > > The change only affects the layout of virtio PCI. Arches that don't > > have PCI don't use virtio PCI, presumably? > > > > BTW, the spec only covers x86 ATM, this needs to be fixed. > > From what I see there is a WIP by Pawel Moll <[email protected]> to add > virtio platform drivers which get virtio working on ARM for example, and > by Peter Maydell <[email protected]> to modify the spec to > support MMIO access (besides PCI). Yep, it's actually already in 3.2-rc1 (drivers/virtio/virtio_mmio.c) and in the spec (see Appendix X). And actually the control registers layout I used was originally based on the PCI "legacy" headers (slightly simplified), but evolved a bit since. My understanding is that the changes Michael is proposing affect the PCI device interface only so they shouldn't affect "my" interface. By the way, I vaguely remember Peter mentioning that he got the PCI device "experimentally" running some time ago on one of the PCI-enabled ARM platform models (realview or versatile)... Cheers! Pawel _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
