qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: "Daniel P. Berrangé" <berrange@redhat.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: Helge Deller <deller@gmx.de>,
	Peter Maydell <peter.maydell@linaro.org>,
	Michael Tokarev <mjt@tls.msk.ru>,
	Samuel Thibault <samuel.thibault@ens-lyon.org>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Aurelien Jarno <aurelien@aurel32.net>
Subject: Re: [Qemu-devel] [PATCH] configure: Automatically fall back to TCI on non-release architectures
Date: Fri, 5 Apr 2019 10:02:12 +0100	[thread overview]
Message-ID: <20190405090212.GF6105@redhat.com> (raw)
In-Reply-To: <068f4832-7e0b-8850-ffa0-fcf1ecd50295@redhat.com>

On Fri, Apr 05, 2019 at 10:47:54AM +0200, Philippe Mathieu-Daudé wrote:
> Hi Helge,
> 
> On 4/5/19 9:56 AM, Helge Deller wrote:
> > On 05.04.19 03:34, Peter Maydell wrote:
> >> On Fri, 5 Apr 2019 at 01:59, Helge Deller <deller@gmx.de> wrote:
> >>> If a non-release architecture is found, and it's known that there is no
> >>> native TCG support for that CPU, automatically fall back to the TCI
> >>> implementation instead of requesting the user to run configure again
> >>> with the --enable-tcg-interpreter option.
> >>>
> >>> This change simplifies building qemu in automatic build environments
> >>> (like in my case the debian buildds) because one does not need to
> >>> special case on the architectures.
> >>
> >> I don't think we should do this. TCI is unmaintained, has several
> >> known flaws,
> > 
> > Just out of interest: Is there a list with those flaws somewhere?
> 
> The last big discussion is in this thread:
> https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg06528.html

Do the various crashes that you illustrate in that cover letter
still exist today ? If so, 2 years of continued brokenness with no
fixes would reinforce the the view that it is time to remove TCI
from the codebase.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

WARNING: multiple messages have this Message-ID (diff)
From: "Daniel P. Berrangé" <berrange@redhat.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
	Helge Deller <deller@gmx.de>, Michael Tokarev <mjt@tls.msk.ru>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Samuel Thibault <samuel.thibault@ens-lyon.org>,
	Aurelien Jarno <aurelien@aurel32.net>
Subject: Re: [Qemu-devel] [PATCH] configure: Automatically fall back to TCI on non-release architectures
Date: Fri, 5 Apr 2019 10:02:12 +0100	[thread overview]
Message-ID: <20190405090212.GF6105@redhat.com> (raw)
Message-ID: <20190405090212.L2RBuNeZcMRGYP1p_pMn3XY-Q9--14COr7yq-hm9ze4@z> (raw)
In-Reply-To: <068f4832-7e0b-8850-ffa0-fcf1ecd50295@redhat.com>

On Fri, Apr 05, 2019 at 10:47:54AM +0200, Philippe Mathieu-Daudé wrote:
> Hi Helge,
> 
> On 4/5/19 9:56 AM, Helge Deller wrote:
> > On 05.04.19 03:34, Peter Maydell wrote:
> >> On Fri, 5 Apr 2019 at 01:59, Helge Deller <deller@gmx.de> wrote:
> >>> If a non-release architecture is found, and it's known that there is no
> >>> native TCG support for that CPU, automatically fall back to the TCI
> >>> implementation instead of requesting the user to run configure again
> >>> with the --enable-tcg-interpreter option.
> >>>
> >>> This change simplifies building qemu in automatic build environments
> >>> (like in my case the debian buildds) because one does not need to
> >>> special case on the architectures.
> >>
> >> I don't think we should do this. TCI is unmaintained, has several
> >> known flaws,
> > 
> > Just out of interest: Is there a list with those flaws somewhere?
> 
> The last big discussion is in this thread:
> https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg06528.html

Do the various crashes that you illustrate in that cover letter
still exist today ? If so, 2 years of continued brokenness with no
fixes would reinforce the the view that it is time to remove TCI
from the codebase.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|


  parent reply	other threads:[~2019-04-05  9:04 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-04 18:57 [Qemu-devel] [PATCH] configure: Automatically fall back to TCI on non-release architectures Helge Deller
2019-04-04 19:24 ` Philippe Mathieu-Daudé
2019-04-05  7:14   ` Helge Deller
2019-04-05  7:14     ` Helge Deller
2019-04-05  1:34 ` Peter Maydell
2019-04-05  1:34   ` Peter Maydell
2019-04-05  7:56   ` Helge Deller
2019-04-05  7:56     ` Helge Deller
2019-04-05  8:26     ` Daniel P. Berrangé
2019-04-05  8:26       ` Daniel P. Berrangé
2019-04-05  9:02       ` Helge Deller
2019-04-05  9:02         ` Helge Deller
2019-04-05  9:10         ` Philippe Mathieu-Daudé
2019-04-05  9:10           ` Philippe Mathieu-Daudé
2019-04-05  9:13         ` Peter Maydell
2019-04-05  9:13           ` Peter Maydell
2019-04-05  9:15         ` Daniel P. Berrangé
2019-04-05  9:15           ` Daniel P. Berrangé
2019-04-05  8:47     ` Philippe Mathieu-Daudé
2019-04-05  8:47       ` Philippe Mathieu-Daudé
2019-04-05  9:02       ` Daniel P. Berrangé [this message]
2019-04-05  9:02         ` Daniel P. Berrangé
2019-04-05  9:16         ` Philippe Mathieu-Daudé
2019-04-05  9:16           ` Philippe Mathieu-Daudé
2019-04-09 19:46           ` Stefan Weil
2019-04-09 19:46             ` Stefan Weil
2019-04-09 20:39             ` Richard Henderson
2019-04-09 20:39               ` Richard Henderson
2019-04-10  6:17               ` Stefan Weil
2019-04-10  6:17                 ` Stefan Weil
2019-04-11  6:21                 ` Richard Henderson
2019-04-11  6:21                   ` Richard Henderson
2019-04-10  6:07             ` Thomas Huth
2019-04-10  6:07               ` Thomas Huth
2019-04-10  6:24               ` Stefan Weil
2019-04-10  6:24                 ` Stefan Weil
2019-04-10  8:22               ` Thomas Huth
2019-04-10  8:22                 ` Thomas Huth
2019-04-10 19:22                 ` Stefan Weil
2019-04-10 19:22                   ` Stefan Weil
2019-04-10  7:48             ` Thomas Huth
2019-04-10  7:48               ` Thomas Huth
2019-04-06  8:59     ` Richard Henderson
2019-04-06  8:59       ` Richard Henderson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190405090212.GF6105@redhat.com \
    --to=berrange@redhat.com \
    --cc=aurelien@aurel32.net \
    --cc=deller@gmx.de \
    --cc=mjt@tls.msk.ru \
    --cc=peter.maydell@linaro.org \
    --cc=philmd@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=samuel.thibault@ens-lyon.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).