From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elsayed Subject: Re: [virtio-dev] Re: [PATCH] Add virtio gpu driver. Date: Thu, 26 Mar 2015 15:49:22 -0700 Message-ID: References: <20150325162246-mutt-send-email-mst@redhat.com> <1427297836.23304.29.camel@nilsson.home.kraxel.org> <20150325180721-mutt-send-email-mst@redhat.com> <1427353959.9779.2.camel@nilsson.home.kraxel.org> <20150326091545-mutt-send-email-mst@redhat.com> <1427359367.9779.9.camel@nilsson.home.kraxel.org> <20150326095736-mutt-send-email-mst@redhat.com> <1427369923.9779.18.camel@nilsson.home.kraxel.org> <20150326124751-mutt-send-email-mst@redhat.com> <1427382436.8786.15.camel@nilsson.home.kraxel.org> <20150326174401-mutt-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit Return-path: Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org List-Id: linux-api@vger.kernel.org Michael S. Tsirkin wrote: > On Thu, Mar 26, 2015 at 04:07:16PM +0100, Gerd Hoffmann wrote: >> Hi, >> >> > I don't know. This seems exactly like the kind of thing >> > we had in mind when we added the virtio pci capability. >> > For example, we have text in spec that requires drivers >> > to skip unknown capabilities. >> > >> > And yes, if bios pokes at a specific bar then we do >> > need to list this info in the virtio spec so this makes >> > it an issue that is virtio related. >> >> Hmm, virtio-vga is a two-in-one device basically. When virtio is >> enabled it behaves like virtio-gpu-pci, otherwise it behaves very >> simliar to stdvga. So you need to know nothing about virtio to handle >> the vga side, and I want keep it that way. >> >> When no vga compatibility is needed there always is the option to just >> use virtio-gpu-pci instead. >> >> > Yes, it's not about what we put there now. It's about being able >> > to move things about in the future without breaking guests. >> >> We don't have that today for stdvga, and I still fail to see what this >> buys us. >> >> >> Completely different thing crossing my mind: I think we can make >> virtio-vga fully compatible with stdvga. stdvga has two bars, memory >> (#0) and mmio (#2). We can make the mmio bar larger and place all the >> virtio regions there. >> > > Full compatibility with some standard sounds like a better motivation, > yes. I think you misunderstand; stdvga is a specific qemu device that only provides the VGA interface. This proposed GPU provides both the VGA interface (the BAR in question) _and_ a virtio interface. >> >> I think in any case I'll go split off the vga compatibility bits to a >> different patch (and possible a separate patch series). >> >> cheers, >> Gerd > > Will you still need me to change core to claim specific memory only? > >