Messages in this thread | | | Subject | Re: [PATCH RFC] virtio-spec: flexible configuration layout | From | Sasha Levin <> | Date | Wed, 09 Nov 2011 12:20:17 +0200 |
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On Wed, 2011-11-09 at 12:18 +0200, Michael S. Tsirkin wrote: > On Wed, Nov 09, 2011 at 11:55:02AM +0200, Sasha Levin wrote: > > On Tue, 2011-11-08 at 23:40 +0200, Michael S. Tsirkin wrote: > > > Here's a spec change documenting what my C patch does > > > (almost - I tweaked the layout a bit, but the idea is the same). > > > Some more cleanups are needed but I thought I'd send it > > > for early flames/comments. > > > > > > The idea is simple: we split functionally unrelated > > > register groups to independent structures, and let > > > the device place is anywhere using a capability > > > in PCI configuration space. > > > > 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). > > A bit of confusion here: no register is moved from memory into > configuration space. Configuration space only gains a list of > pointers into memory/pio space.
The definition of the way the virtio configuration space looks is moved into PCI configuration space, it was constant before.
> > 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 <pawel.moll@arm.com> to add virtio platform drivers which get virtio working on ARM for example, and by Peter Maydell <peter.maydell@linaro.org> to modify the spec to support MMIO access (besides PCI).
Maybe worth seeing if it works for them...
--
Sasha.
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