From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40269) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eAYwO-0007hW-QX for qemu-devel@nongnu.org; Fri, 03 Nov 2017 06:11:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eAYwK-00014G-Ql for qemu-devel@nongnu.org; Fri, 03 Nov 2017 06:11:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59358) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eAYwK-00013F-KV for qemu-devel@nongnu.org; Fri, 03 Nov 2017 06:11:04 -0400 Date: Fri, 3 Nov 2017 10:10:55 +0000 From: "Daniel P. Berrange" Message-ID: <20171103101055.GD20155@redhat.com> Reply-To: "Daniel P. Berrange" References: <1509638660.11873.13.camel@redhat.com> <20171102161103.GU32533@redhat.com> <1509691743.31823.1.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1509691743.31823.1.camel@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] seabios serial console vs. sgabios List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: seabios , "qemu-devel@nongnu.org" , Paolo Bonzini On Fri, Nov 03, 2017 at 07:49:03AM +0100, Gerd Hoffmann wrote: > On Thu, 2017-11-02 at 16:11 +0000, Daniel P. Berrange wrote: > > On Thu, Nov 02, 2017 at 05:04:20PM +0100, Gerd Hoffmann wrote: > > > =C2=A0 Hi, > > >=20 > > > One problem we have with the serial console support in seabios and > > > sgabios:=C2=A0=C2=A0It can happen that both are activated.=C2=A0=C2= =A0We'll go fix that > > > in > > > qemu, but that'll work for new qemu versions only, not for the old > > > already released ones. > > >=20 > > > So I think it would be useful if seabios makes sure sgabios and > > > serial > > > console are not both active at the same time, i.e. in case we find > > > "vgaroms/sgabios.bin" being present either turn off builtin serial > > > console, or don't load sgabios (and possibly also enable builtin > > > serial > > > console). > >=20 > > Historically libvirt will always use '-device sgabios' if the user > > has > > requested .=C2=A0=C2=A0So if that -device ar= g is given, > > I > > think QEMU must honour it, which implies QEMU must disable Seabios' > > own built-in serial console impl in that scenario. >=20 > Hmm, why? The user asked for a serial console. Whenever that is > provided by seabios builtin support or the sgabios rom doesn't really > matter, no? Surely it has ABI implications for the guest if we stop putting the sgabios option ROM into memory - changing layout of ROMS > Also, the question is what seabios should do in case both are active.=20 > Which I think can happen today with libvirt if you configure a virtual > machine without vga (libvirt passes -machine graphics=3Doff which > activates builtin serial console) and with "" > (enables sgabios rom). Libvirt doesn't use '-machine graphics=3Doff' AFAIK, only '-nographic'.=20 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|