From: Peter Maydell <peter.maydell@linaro.org>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Laurent Vivier" <lvivier@redhat.com>,
"Thomas Huth" <thuth@redhat.com>,
"Alex Bennée" <alex.bennee@linaro.org>,
"QEMU Developers" <qemu-devel@nongnu.org>,
qemu-ppc <qemu-ppc@nongnu.org>,
"Philippe Mathieu-Daudé" <philmd@redhat.com>,
"Thiago Jung Bauermann" <bauerman@linux.ibm.com>,
"David Gibson" <david@gibson.dropbear.id.au>
Subject: Re: [PATCH] cpu: Add starts_halted() method
Date: Wed, 8 Jul 2020 16:32:51 +0100 [thread overview]
Message-ID: <CAFEAcA8mFM-O=mgCQHNz4TNB5N3Trid2o95s0Nx7JVp_q_dSrw@mail.gmail.com> (raw)
In-Reply-To: <20200708152540.GZ7276@habkost.net>
On Wed, 8 Jul 2020 at 16:25, Eduardo Habkost <ehabkost@redhat.com> wrote:
> On Wed, Jul 08, 2020 at 02:14:03PM +0100, Peter Maydell wrote:
> > The original bug as described in the commit message sounds
> > to me like something we should look to fix in the implementation
> > of async_run_on_cpu() -- it shouldn't cause a CPU that's halfway
> > through reset to do a KVM_RUN or otherwise run guest code,
> > whether that CPU is going to start powered-up or powered-down.
>
> What "halfway through reset" means, exactly? Isn't halted==1
> enough to indicate the CPU is in that state?
I mean "while we're in the middle of the CPU method that's
called by cpu_reset()". "halted==1" says "the CPU is halted";
that's not the same thing. KVM_RUN happening
as a side effect in the middle of that code is a bug
whether the CPU happens to be intended to be put into the
halted state or not. If the CPU is intended to be created
not-halted then KVM_RUN can happen after cpu reset
completes, but not before.
thanks
-- PMM
next prev parent reply other threads:[~2020-07-08 15:34 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 20:43 [PATCH] cpu: Add starts_halted() method Thiago Jung Bauermann
2020-07-07 21:49 ` Eduardo Habkost
2020-07-07 23:28 ` Thiago Jung Bauermann
2020-07-08 8:38 ` Philippe Mathieu-Daudé
2020-07-08 10:00 ` David Gibson
2020-07-08 13:14 ` Peter Maydell
2020-07-08 15:25 ` Eduardo Habkost
2020-07-08 15:32 ` Peter Maydell [this message]
2020-07-08 16:03 ` Eduardo Habkost
2020-07-08 17:09 ` Peter Maydell
2020-07-08 17:36 ` Eduardo Habkost
2020-07-08 20:11 ` Peter Maydell
2020-07-08 21:32 ` Eduardo Habkost
2020-07-09 3:05 ` Thiago Jung Bauermann
2020-07-09 3:26 ` Thiago Jung Bauermann
2020-07-09 10:24 ` Philippe Mathieu-Daudé
2020-07-10 20:02 ` Thiago Jung Bauermann
2020-07-10 20:17 ` Eduardo Habkost
[not found] ` <87k0zdm63s.fsf@linaro.org>
2020-07-10 20:16 ` Thiago Jung Bauermann
2020-07-11 17:55 ` Alex Bennée
2020-07-08 16:45 ` Philippe Mathieu-Daudé
2020-07-08 21:39 ` Eduardo Habkost
2020-07-09 5:11 ` Philippe Mathieu-Daudé
2020-07-09 9:54 ` Greg Kurz
2020-07-09 10:18 ` Philippe Mathieu-Daudé
2020-07-09 10:55 ` Greg Kurz
2020-07-09 12:21 ` Philippe Mathieu-Daudé
2020-07-09 13:13 ` Greg Kurz
2020-07-09 13:19 ` Philippe Mathieu-Daudé
2020-07-09 13:40 ` Peter Maydell
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='CAFEAcA8mFM-O=mgCQHNz4TNB5N3Trid2o95s0Nx7JVp_q_dSrw@mail.gmail.com' \
--to=peter.maydell@linaro.org \
--cc=alex.bennee@linaro.org \
--cc=bauerman@linux.ibm.com \
--cc=david@gibson.dropbear.id.au \
--cc=ehabkost@redhat.com \
--cc=lvivier@redhat.com \
--cc=philmd@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-ppc@nongnu.org \
--cc=thuth@redhat.com \
/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).