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Subject: Re: [virtio-dev] Re: [PATCH] Add virtio gpu driver.
From: Gerd Hoffmann <kraxel@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtio-dev@lists.oasis-open.org, Dave Airlie <airlied@gmail.com>,
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Date: Thu, 26 Mar 2015 12:38:43 +0100
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  Hi,

> Absolutely, it's pretty common to mix regions in a BAR.
> For example, we have virtio kick (ioeventfd backed,
> handled in kernel) in same BAR as common and device
> specific configuration.

> We did the same thing you are now doing with the
> virtio BAR, and now we have to maintain two code
> bases, virtio pci config was designed to be future proof
> so why not use it?

It's not about virtio at all.  It's about vga compatibility, so we have
a simple framebuffer as boot display.  Only used when virtio is *not*
enabled.

> This is mostly just making sure we don't paint ourselves into a corner.

It's a simple memory bar.  vga cards have that since pci was invented
(standalone ones, chipset graphics aside), and there havn't been
fundamental changes ...

cheers,
  Gerd