From: Avi Kivity <avi@redhat.com>
To: Eric B Munson <emunson@mgebm.net>
Cc: mingo@redhat.com, hpa@zytor.com, ryanh@linux.vnet.ibm.com,
aliguori@us.ibm.com, mtosatti@redhat.com,
jeremy.fitzhardinge@citrix.com, kvm@vger.kernel.org,
linux-arch@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, Jan Kiszka <jan.kiszka@web.de>
Subject: Re: [PATCH 3/4 V10] Add ioctl for KVMCLOCK_GUEST_STOPPED
Date: Mon, 30 Jan 2012 17:49:46 +0200 [thread overview]
Message-ID: <4F26BC1A.8060002@redhat.com> (raw)
In-Reply-To: <20120130153244.GA6875@mgebm.net>
On 01/30/2012 05:32 PM, Eric B Munson wrote:
> >
> > Can you point me to the discussion that moved this to be a vm ioctl? In
> > general vm ioctls that do things for all vcpus are racy, like here.
> > You're accessing variables that are protected by the vcpu mutex, and not
> > taking the mutex (nor can you, since it is held while the guest is
> > running, unlike most kernel mutexes).
> >
>
> Jan Kiszka suggested that becuase there isn't a use case for notifying
> individual vcpus (can vcpu's be paused individually?
They can, though the guest will grind to a halt very soon.
> ) that it makes more sense
> to have a vm ioctl.
>
> http://thread.gmane.org/gmane.comp.emulators.qemu/131624
>
> If the per vcpu ioctl is the right choice I can resend those patches.
The races are solvable but I think it's easier in userspace. It's also
more flexible, though I don't really see a use for this flexibility.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-01-30 15:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1326825641-15765-1-git-send-email-emunson@mgebm.net>
2012-01-17 18:40 ` [PATCH 1/4 V10] Add flag to indicate that a vm was stopped by the host Eric B Munson
2012-01-17 18:40 ` [PATCH 2/4 V10] Add functions to check if the host has stopped the vm Eric B Munson
2012-01-17 18:40 ` [PATCH 3/4 V10] Add ioctl for KVMCLOCK_GUEST_STOPPED Eric B Munson
2012-01-30 15:07 ` Avi Kivity
2012-01-30 15:11 ` Avi Kivity
2012-01-30 15:33 ` Eric B Munson
2012-01-30 15:32 ` Eric B Munson
2012-01-30 15:49 ` Avi Kivity [this message]
2012-01-30 16:01 ` Eric B Munson
2012-01-30 16:18 ` Jan Kiszka
2012-01-30 17:11 ` Avi Kivity
2012-01-17 18:40 ` [PATCH 4/4 V10] Add check for suspended vm in softlockup detector Eric B Munson
2012-01-27 20:45 ` [PATCH 0/4 V10] Avoid soft lockup message when KVM is stopped by host Eric B Munson
2012-01-30 15:08 ` Avi Kivity
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=4F26BC1A.8060002@redhat.com \
--to=avi@redhat.com \
--cc=aliguori@us.ibm.com \
--cc=emunson@mgebm.net \
--cc=hpa@zytor.com \
--cc=jan.kiszka@web.de \
--cc=jeremy.fitzhardinge@citrix.com \
--cc=kvm@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=mtosatti@redhat.com \
--cc=ryanh@linux.vnet.ibm.com \
--cc=x86@kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.