Status/future of QEMU bsd-user impl ? (Wea Re: [PULL 00/12] Compile QEMU with -Wimplicit-fallthrough)

From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Thomas Huth <thuth@redhat.com>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Ed Maste" <emaste@freebsd.org>,
	"Sean Bruno" <sbruno@freebsd.org>,
	"QEMU Developers" <qemu-devel@nongnu.org>,
	"Kamil Rytarowski" <kamil@netbsd.org>,
	"Chen Qun" <kuhn.chenqun@huawei.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Li-Wen Hsu" <lwhsu@freebsd.org>,
	"Brad Smith" <brad@comstyle.com>
Subject: Status/future of QEMU bsd-user impl ? (Wea Re: [PULL 00/12] Compile QEMU with -Wimplicit-fallthrough)
Date: Thu, 17 Dec 2020 14:00:12 +0000	[thread overview]
Message-ID: <20201217140012.GF247354@redhat.com> (raw)
In-Reply-To: <a6271697-c645-968a-7e0f-e1993140633b@redhat.com>

On Thu, Dec 17, 2020 at 02:03:47PM +0100, Thomas Huth wrote:
> On 17/12/2020 13.51, Peter Maydell wrote:
> > On Wed, 16 Dec 2020 at 17:29, Thomas Huth <thuth@redhat.com> wrote:
> >>
> >>  Hi!
> >>
> >> The following changes since commit af3f37319cb1e1ca0c42842ecdbd1bcfc64a4b6f:
> >>
> >>   Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging (2020-12-15 21:24:31 +0000)
> >>
> >> are available in the Git repository at:
> >>
> >>   https://gitlab.com/huth/qemu.git tags/pull-request-2020-12-16
> >>
> >> for you to fetch changes up to cbbedfeeb77e25b065f8a2b0c33e81403edaf728:
> >>
> >>   configure: Compile with -Wimplicit-fallthrough=2 (2020-12-16 12:52:20 +0100)
> >>
> >> ----------------------------------------------------------------
> >> * Compile QEMU with -Wimplicit-fallthrough=2 to avoid bugs in
> >>   switch-case statements
> >> ----------------------------------------------------------------
> > 
> > Hi; this generates a new warning on the NetBSD build:
> > 
> > ../src/bsd-user/main.c: In function 'cpu_loop':
> > ../src/bsd-user/main.c:513:16: warning: this statement may fall
> > through [-Wimplicit-fallthrough=]
> >              if (bsd_type != target_freebsd)
> >                 ^
> > ../src/bsd-user/main.c:515:9: note: here
> >          case 0x100:
> >          ^~~~
> 
> Oh man, can't we just ditch the bsd-user folder now? It's known to be broken
> since many releases, so it's currently only causing additional effort to
> keep this code compilable (also with regards to the automatic code scan tool
> reports that we've seen during the past months), without real benefit. Even
> if the BSD folks finally upstream their fixed version again, it's more
> likely that they will start from scratch again instead of fixing the old
> folder, I guess?

Yeah, it has been a while since we last discussed this:

  https://lists.gnu.org/archive/html/qemu-devel/2017-01/msg00171.html

Meanwhile their out of free bsd-user impl continues to be developed
until Dec 2019 at least:

  https://github.com/seanbruno/qemu-bsd-user/commits/bsd-user

I don't recall what happened after that initial discussion about
merging the new impl. Did Sean simply not have the time to invest
in the merge ? I'll CC him here to see what opinion he has on the
future of bsd-user in QEMU.

Regards,
Daniel
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