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 15:50 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
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