From: "Richard W.M. Jones" <rjones@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Cole Robinson <crobinso@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
qemu-arm <qemu-arm@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH] hw/arm/virt: Reject gic-version=host for non-KVM
Date: Fri, 17 Jun 2016 17:10:16 +0100 [thread overview]
Message-ID: <20160617161016.GU16797@redhat.com> (raw)
In-Reply-To: <CAFEAcA8QmK+_cHfPuk90poixxbqSJpb+OuoXg-3OnXcfRYKQUg@mail.gmail.com>
On Fri, Jun 17, 2016 at 03:49:38PM +0100, Peter Maydell wrote:
> On 26 May 2016 at 15:53, Peter Maydell <peter.maydell@linaro.org> wrote:
> > On 26 May 2016 at 15:46, Richard W.M. Jones <rjones@redhat.com> wrote:
> >> The problem with this is if I'm using TCG fallback mode, how
> >> can I specify the right gic-version? ie:
> >>
> >> -M virt,gic-version=host,accel=kvm:tcg
> >>
> >> Only qemu knows if KVM is going to be enabled.
> >>
> >> The same problem happens with '-cpu host' BTW. I really want a "make
> >> it work" option, as I've said on several previous occasions on this
> >> list eg:
> >> https://lists.nongnu.org/archive/html/qemu-devel/2014-08/msg04173.html
> >
> > I agree that we really need to do better here (thinking about
> > the problem is on my todo list but generally other more pressing
> > issues intervene). I'd welcome suggestions for semantics which
> > (a) do what you want (b) are reasonably in line with what we do
> > on other host architectures (c) don't break existing command lines.
> > (I think those are the main requirements.)
>
> ...so does anybody have any concrete suggestions? We could fix
> this for 2.7 but we're starting to run low on time for that.
I have changed libguestfs so it tries to guess if KVM will be used or
not. We have to do this for the -cpu option too, but the guess is not
too reliable. Only QEMU has the actual knowledge we need.
https://github.com/libguestfs/libguestfs/commit/7023f20830a681ef36f8f99415fe41791555a3db
Can we not have a "give me a GIC which will work" option, eg.
-M virt,gic-version=besteffort,accel=kvm:tcg
I don't care if it's not the fastest or most featureful.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top
next prev parent reply other threads:[~2016-06-17 16:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-26 14:31 [Qemu-devel] [PATCH] hw/arm/virt: Reject gic-version=host for non-KVM Cole Robinson
2016-05-26 14:46 ` Richard W.M. Jones
2016-05-26 14:53 ` Peter Maydell
2016-05-26 15:14 ` Richard W.M. Jones
2016-06-17 14:49 ` Peter Maydell
2016-06-17 16:10 ` Richard W.M. Jones [this message]
2016-06-17 16:31 ` Peter Maydell
2016-06-17 16:33 ` Richard W.M. Jones
2016-06-03 18:34 ` Peter Maydell
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