From: Mark McLoughlin <markmc@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>, kvm-devel <kvm@vger.kernel.org>
Subject: Re: Loss of lock drop in qemu/net.c
Date: Wed, 17 Dec 2008 09:19:23 +0000 [thread overview]
Message-ID: <1229505563.3685.37.camel@localhost.localdomain> (raw)
In-Reply-To: <4948039B.7060400@redhat.com>
On Tue, 2008-12-16 at 21:38 +0200, Avi Kivity wrote:
> The recent qemu merged does not allow net.h to include kvm code (due to
> a dependency on cpu.h). This means I had to drop the
> kvm_sleep_begin()/kvm_sleep_end() around the packet send (which, btw,
> makes the whole thing vulnerable to hotunplug; we need refcounting or
> locking here).
How can the tap vlan client be affected by hotunplug?
(Dropping the lock from a hotunpluggable PCI device like virtio_net
would be dangerous - even though the removal is done by the monitor in
the I/O thread and so can't happen while the thread is sleeping, the
device isn't actually removed until the guest has acked it with EJ0 and
this would be handled by a vcpu thread)
Cheers,
Mark.
next prev parent reply other threads:[~2008-12-17 9:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-16 19:38 Loss of lock drop in qemu/net.c Avi Kivity
2008-12-16 20:25 ` Anthony Liguori
2008-12-17 9:38 ` Avi Kivity
2008-12-17 9:19 ` Mark McLoughlin [this message]
2008-12-17 9:39 ` Avi Kivity
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