From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH] virtio_net: Fix oops on early interrupts - introduced by virtio reset code Date: Mon, 11 Feb 2008 09:29:36 -0600 Message-ID: <47B069E0.9040905@us.ibm.com> References: <200802111411.15745.borntraeger@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , dor.laor@qumranet.com, kvm-devel , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org To: Christian Borntraeger Return-path: Received: from e4.ny.us.ibm.com ([32.97.182.144]:51864 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753205AbYBKP3i (ORCPT ); Mon, 11 Feb 2008 10:29:38 -0500 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e4.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m1BFTatl015855 for ; Mon, 11 Feb 2008 10:29:36 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1BFTa5Z249462 for ; Mon, 11 Feb 2008 10:29:36 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m1BFTZBp014461 for ; Mon, 11 Feb 2008 10:29:36 -0500 In-Reply-To: <200802111411.15745.borntraeger@de.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: Christian Borntraeger wrote: > Avi, > this fixes a problem that was introduced by the virtio_reset patches. > Can you apply that fix to kvm.git as a bugfix, as the virtio_reset > infrastructure is not on Linus upstream yet? > The reset support is in Linus's tree so we should try to push it for -rc2. > Anthony, Dor, > are you ok with that change? > Yes. Acked-by: Anthony Liguori Regards, Anthony Liguori > -- > > With the latest virtio_reset patches I got the following oops: > > Unable to handle kernel pointer dereference at virtual kernel address 0000000000000000 > Oops: 0004 [#1] PREEMPT SMP > Modules linked in: > CPU: 1 Not tainted 2.6.24zlive-guest-10577-g63f5307-dirty #168 > Process swapper (pid: 0, task: 000000000f866040, ksp: 000000000f86fd78) > Krnl PSW : 0404100180000000 000000000047598a (skb_recv_done+0x52/0x98) > R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 EA:3 > Krnl GPRS: 0000000000000001 0000000000000000 000000000efd0e60 0000000000000001 > 0000000000000000 000000000f866040 0000000000000000 0000000000000000 > 00000000008de4c8 0000000000001237 0000000000001237 000000000f977dd8 > 0000000000000020 00000000001132bc 000000000f977e08 000000000f977dd8 > Krnl Code: 000000000047597c: e31040300004 lg %r1,48(%r4) > 0000000000475982: b9040001 lgr %r0,%r1 > 0000000000475986: b9810003 ogr %r0,%r3 > >000000000047598a: eb1040300030 csg %r1,%r0,48(%r4) > 0000000000475990: a744fff9 brc 4,475982 > 0000000000475994: a7110001 tmll %r1,1 > 0000000000475998: a7840009 brc 8,4759aa > 000000000047599c: e340b0b80004 lg %r4,184(%r11) > Call Trace: > ([<000001500f978000>] 0x1500f978000) > [<00000000004779a6>] vring_interrupt+0x72/0x88 > [<0000000000491d9c>] kvm_extint_handler+0x34/0x44 > [<000000000010d2d4>] do_extint+0xc0/0xfc > [<0000000000113b5a>] ext_no_vtime+0x1c/0x20 > [<000000000010a0b6>] cpu_idle+0x21a/0x230 > > > We must initialize vdev->priv before we use the notify hypercall as > vdev->priv is used in skb_recv_done. So lets move the assignment of > vdev->priv before we call try_fill_recv. > > Signed-off-by: Christian Borntraeger > --- > drivers/net/virtio_net.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: kvm/drivers/net/virtio_net.c > =================================================================== > --- kvm.orig/drivers/net/virtio_net.c > +++ kvm/drivers/net/virtio_net.c > @@ -361,6 +361,7 @@ static int virtnet_probe(struct virtio_d > netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); > vi->dev = dev; > vi->vdev = vdev; > + vdev->priv = vi; > > /* We expect two virtqueues, receive then send. */ > vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done); > @@ -395,7 +396,6 @@ static int virtnet_probe(struct virtio_d > } > > pr_debug("virtnet: registered device %s\n", dev->name); > - vdev->priv = vi; > return 0; > > unregister: >