From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751749AbbCZISL (ORCPT ); Thu, 26 Mar 2015 04:18:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35767 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751082AbbCZISH (ORCPT ); Thu, 26 Mar 2015 04:18:07 -0400 Date: Thu, 26 Mar 2015 09:18:01 +0100 From: "Michael S. Tsirkin" To: Gerd Hoffmann Cc: virtio-dev@lists.oasis-open.org, Dave Airlie , Dave Airlie , David Airlie , Rusty Russell , open list , "open list:DRM DRIVERS" , "open list:VIRTIO CORE, NET..." , "open list:ABI/API" Subject: Re: [PATCH] Add virtio gpu driver. Message-ID: <20150326091545-mutt-send-email-mst@redhat.com> References: <1427213239-8775-1-git-send-email-kraxel@redhat.com> <20150324171255-mutt-send-email-mst@redhat.com> <1427295121.23304.5.camel@nilsson.home.kraxel.org> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427353959.9779.2.camel@nilsson.home.kraxel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 26, 2015 at 08:12:39AM +0100, Gerd Hoffmann wrote: > On Mi, 2015-03-25 at 18:09 +0100, Michael S. Tsirkin wrote: > > On Wed, Mar 25, 2015 at 04:37:16PM +0100, Gerd Hoffmann wrote: > > > Hi, > > > > > > > BTW can we teach virtio-gpu to look for framebuffer using > > > > virtio pci caps? > > > > > > The virtio-gpu driver doesn't matter much here, it doesn't use it > > > anyway. > > > > > > > Or are there limitations such as only > > > > using IO port BARs, or compatibility with > > > > BIOS code etc that limit us to specific BARs anyway? > > > > > > Yes, vgabios code needs to know. Currently it has bar #2 for the vga > > > framebuffer bar hardcoded. It's 16bit code. I don't feel like making > > > the probing more complicated ... > > > > > > cheers, > > > Gerd > > > > OK - you are saying all VGA cards use bar #2 for this > > functionality, so we are just following > > established practice here? > > vgabios checks pci ids to figure. qxl+stdvga use bar #0, vmware-vga bar > #1, virtio-vga bar #2. > > cheers, > Gerd > And is it possible to use offset within BAR and/or memory BARs? If yes I'd strongly prefer this. As for writing 16 bit code, I need to do this for virtio scsi/blk anyway, so we'll be able to share code. -- MST From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] Add virtio gpu driver. Date: Thu, 26 Mar 2015 09:18:01 +0100 Message-ID: <20150326091545-mutt-send-email-mst@redhat.com> References: <1427213239-8775-1-git-send-email-kraxel@redhat.com> <20150324171255-mutt-send-email-mst@redhat.com> <1427295121.23304.5.camel@nilsson.home.kraxel.org> <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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1427353959.9779.2.camel-3OfP5uLMi4C46o+2HkPkLj4oCIwMql/M@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Gerd Hoffmann Cc: virtio-dev-sDuHXQ4OtrM4h7I2RyI4rWD2FQJk+8+b@public.gmane.org, Dave Airlie , Dave Airlie , David Airlie , Rusty Russell , open list , "open list:DRM DRIVERS" , "open list:VIRTIO CORE, NET..." , "open list:ABI/API" List-Id: linux-api@vger.kernel.org On Thu, Mar 26, 2015 at 08:12:39AM +0100, Gerd Hoffmann wrote: > On Mi, 2015-03-25 at 18:09 +0100, Michael S. Tsirkin wrote: > > On Wed, Mar 25, 2015 at 04:37:16PM +0100, Gerd Hoffmann wrote: > > > Hi, > > > > > > > BTW can we teach virtio-gpu to look for framebuffer using > > > > virtio pci caps? > > > > > > The virtio-gpu driver doesn't matter much here, it doesn't use it > > > anyway. > > > > > > > Or are there limitations such as only > > > > using IO port BARs, or compatibility with > > > > BIOS code etc that limit us to specific BARs anyway? > > > > > > Yes, vgabios code needs to know. Currently it has bar #2 for the vga > > > framebuffer bar hardcoded. It's 16bit code. I don't feel like making > > > the probing more complicated ... > > > > > > cheers, > > > Gerd > > > > OK - you are saying all VGA cards use bar #2 for this > > functionality, so we are just following > > established practice here? > > vgabios checks pci ids to figure. qxl+stdvga use bar #0, vmware-vga bar > #1, virtio-vga bar #2. > > cheers, > Gerd > And is it possible to use offset within BAR and/or memory BARs? If yes I'd strongly prefer this. As for writing 16 bit code, I need to do this for virtio scsi/blk anyway, so we'll be able to share code. -- MST