From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: qemu-xen-dir + PCI passthrough = BOOM Date: Wed, 18 Dec 2013 11:18:36 -0500 Message-ID: <20131218161836.GB7405@pegasus.dumpdata.com> References: <20131205121632.GO10855@perard.uk.xensource.com> <20131206144935.GA3603@pegasus.dumpdata.com> <20131206153503.GS10855@perard.uk.xensource.com> <20131206160018.GC4419@zion.uk.xensource.com> <20131206160310.GD4419@zion.uk.xensource.com> <20131216150816.GA14122@phenom.dumpdata.com> <20131218144823.GB6081@perard.uk.xensource.com> <1387378646.28680.48.camel@kazak.uk.xensource.com> <20131218152235.GG4934@phenom.dumpdata.com> <1387383185.28680.60.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VtJpd-00089z-B4 for xen-devel@lists.xenproject.org; Wed, 18 Dec 2013 16:18:45 +0000 Content-Disposition: inline In-Reply-To: <1387383185.28680.60.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Anthony PERARD , xen-devel@lists.xenproject.org, stefano.stabellini@citrix.com List-Id: xen-devel@lists.xenproject.org On Wed, Dec 18, 2013 at 04:13:05PM +0000, Ian Campbell wrote: > On Wed, 2013-12-18 at 10:22 -0500, Konrad Rzeszutek Wilk wrote: > > load_roms and bios_load are not set - so it wouldn't even do it. > > It only does it for Bochs BIOS. > > Right, this is deliberate. > > For ROMBIOS (AKA BOchs BIOS) hvmloader loads the options roms. and I > think ROMBIOS subsequently loads them. > > For SeaBIOS it is the BIOS itself which both loads and executes the > ROMS, which is why it is NULL in hvmloader. Aha! > > The SeaBIOS way is far more like how systems normally work and because > the BIOS is in charge it can do a better job than splitting it between > two entities. > > Seems like perhaps I was mistaken about hvmloader+rombios not supporting > loading from the ROM BAR of the device, it does seem to have some > limited support for that (serial controllers and disk controllers only) > > hvmloader+rombios does hardcode the VGA bios (rather than getting it > from the emulated devices ROM bar), which is probably what I was > thinking of, that's why people doing VGA passthrough with rombios need > to grab the bios image and build it into hvmloader. Right, which I hope to fix to make this work without this madness. > > hvmloader+rombios also hardcodes the etherboot rom. > > Ian. >