From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Eric B Munson <emunson@mgebm.net>,
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
Subject: Re: [PATCH 3/4 V10] Add ioctl for KVMCLOCK_GUEST_STOPPED
Date: Mon, 30 Jan 2012 19:11:25 +0200 [thread overview]
Message-ID: <4F26CF3D.4070001@redhat.com> (raw)
In-Reply-To: <4F26C2EC.5070303@siemens.com>
On 01/30/2012 06:18 PM, Jan Kiszka wrote:
> >
> > This looks racy. The vcpu can remove its kvmclock concurrently with
> > this access, and src will be NULL.
>
> There is no race here (src is member of the vcpu), but arch.time might
> have become invalid. KVM_REQ_CLOCK_UPDATE instead of mark_page_dirty
> would indeed be the way to go. Trivial solution, I would say.
>
> However, the concept of "guest stopped" has VM, not VCPU scope.
We're not stopping the guest here, just setting a flag in kvmclock,
which certainly is a per-vcpu thing.
> That
> makes the call more appropriate as a VM ioctl. If that thing should
> really become per-vcpu, at least call it KVMCLOCK_VCPU_STOPPED.
>
All current ioctls start with KVM_. Maybe KVM_KVMCLOCK_CTRL?
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-01-30 17:12 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
2012-01-30 16:01 ` Eric B Munson
2012-01-30 16:18 ` Jan Kiszka
2012-01-30 17:11 ` Avi Kivity [this message]
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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