From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42736) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YsxLR-0002qJ-NQ for qemu-devel@nongnu.org; Thu, 14 May 2015 13:54:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YsxLN-00070M-MQ for qemu-devel@nongnu.org; Thu, 14 May 2015 13:54:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35732) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YsxLN-00070F-HA for qemu-devel@nongnu.org; Thu, 14 May 2015 13:54:49 -0400 Message-ID: <5554E166.7050909@redhat.com> Date: Thu, 14 May 2015 13:54:46 -0400 From: John Snow MIME-Version: 1.0 References: <20150513174204.GS23627@redhat.com> <5553C651.4060000@redhat.com> <20150514111825.GE3441@redhat.com> <878ucr4bb7.fsf@blackfin.pond.sub.org> <20150514160545-mutt-send-email-mst@redhat.com> In-Reply-To: <20150514160545-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] Do not emulate a floppy drive when -nodefaults List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , Markus Armbruster Cc: Kevin Wolf , xen-devel@lists.xensource.com, Stefano Stabellini , qemu-devel@nongnu.org, pbonzini@redhat.com, rth@twiddle.net On 05/14/2015 10:07 AM, Michael S. Tsirkin wrote: > On Thu, May 14, 2015 at 02:02:04PM +0200, Markus Armbruster wrote: >> Correct. >> >> Here's how I think it should be done: >> >> * Create a machine option to control the FDC >> >> This is a machine-specific option. It should only exist for machine >> types that have an optional FDC. >> >> Default must be "on" for old machine types. Default may be "off" fo= r >> new machine types. >> >> It should certainly be off for pc-q35-2.4 and newer. Real Q35 board= s >> commonly don't have an FDC (depends on the Super I/O chip used). >> >> We may want to keep it off for pc-i440fx-2.4 and newer. I doubt >> there's a real i440FX without an FDC, but our virtual i440FX is quit= e >> unlike a real one in other ways already. >=20 > I think making it off by default is a bad idea, it will break > command-line users. >=20 >=20 If we can add a flag to disable it, I still think I wouldn't mind that, if it could be worked out to not be hacky and gross. >> * Create the FDC only if the option is "on". >> >> * Optional: make -drive if=3Dfloppy,... auto-enable it >=20 > Every time we do such auto hacks, we regret this later. > Just do what we are told, fail if=3Dfloppy if disabled. >=20 I agree very much. Just because the current drive/device syntax is almost totally hosed doesn't mean we should put more wood on the fire. >> I wouldn't bother doing the same for -global isa-fdc.driveA=3D... an= d >> such. >> >> Stefano, if you're willing to tackle this, go right ahead! I'm definitely against a "--seriously-nothing" flag because the line for what is embedded or not is fuzzy. Paolo raises some good points against where you draw the line for what we decide to allow users to include/exclude that is otherwise considered part of the board. Still, given the hype train, if there is an API we could introduce that is likely not to make our code gross (or make us belly-ache about how dumb we were in 5 years) that disables the FDC, I don't think I would mind terribly. I'll leave that to minds more opinionated than mine to hash out, though. Maybe the best option here really is to carefully separate optional from non-optional components (FDC vs. Floppy Drive, Floppy Disk code) and just give the core FDC code a good scrubbing. --js From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Snow Subject: Re: [PATCH] Do not emulate a floppy drive when -nodefaults Date: Thu, 14 May 2015 13:54:46 -0400 Message-ID: <5554E166.7050909@redhat.com> References: <20150513174204.GS23627@redhat.com> <5553C651.4060000@redhat.com> <20150514111825.GE3441@redhat.com> <878ucr4bb7.fsf@blackfin.pond.sub.org> <20150514160545-mutt-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20150514160545-mutt-send-email-mst@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: "Michael S. Tsirkin" , Markus Armbruster Cc: Kevin Wolf , xen-devel@lists.xensource.com, Stefano Stabellini , qemu-devel@nongnu.org, pbonzini@redhat.com, rth@twiddle.net List-Id: xen-devel@lists.xenproject.org On 05/14/2015 10:07 AM, Michael S. Tsirkin wrote: > On Thu, May 14, 2015 at 02:02:04PM +0200, Markus Armbruster wrote: >> Correct. >> >> Here's how I think it should be done: >> >> * Create a machine option to control the FDC >> >> This is a machine-specific option. It should only exist for machine >> types that have an optional FDC. >> >> Default must be "on" for old machine types. Default may be "off" fo= r >> new machine types. >> >> It should certainly be off for pc-q35-2.4 and newer. Real Q35 board= s >> commonly don't have an FDC (depends on the Super I/O chip used). >> >> We may want to keep it off for pc-i440fx-2.4 and newer. I doubt >> there's a real i440FX without an FDC, but our virtual i440FX is quit= e >> unlike a real one in other ways already. >=20 > I think making it off by default is a bad idea, it will break > command-line users. >=20 >=20 If we can add a flag to disable it, I still think I wouldn't mind that, if it could be worked out to not be hacky and gross. >> * Create the FDC only if the option is "on". >> >> * Optional: make -drive if=3Dfloppy,... auto-enable it >=20 > Every time we do such auto hacks, we regret this later. > Just do what we are told, fail if=3Dfloppy if disabled. >=20 I agree very much. Just because the current drive/device syntax is almost totally hosed doesn't mean we should put more wood on the fire. >> I wouldn't bother doing the same for -global isa-fdc.driveA=3D... an= d >> such. >> >> Stefano, if you're willing to tackle this, go right ahead! I'm definitely against a "--seriously-nothing" flag because the line for what is embedded or not is fuzzy. Paolo raises some good points against where you draw the line for what we decide to allow users to include/exclude that is otherwise considered part of the board. Still, given the hype train, if there is an API we could introduce that is likely not to make our code gross (or make us belly-ache about how dumb we were in 5 years) that disables the FDC, I don't think I would mind terribly. I'll leave that to minds more opinionated than mine to hash out, though. Maybe the best option here really is to carefully separate optional from non-optional components (FDC vs. Floppy Drive, Floppy Disk code) and just give the core FDC code a good scrubbing. --js