From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Borntraeger Subject: [PATCH] virtio_net: Fix oops on early interrupts - introduced by virtio reset code Date: Mon, 11 Feb 2008 14:11:15 +0100 Message-ID: <200802111411.15745.borntraeger@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: dor.laor@qumranet.com, Anthony Liguori , "kvm-devel" , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org To: Avi Kivity Return-path: Received: from mtagate1.uk.ibm.com ([195.212.29.134]:37553 "EHLO mtagate1.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754044AbYBKNL0 (ORCPT ); Mon, 11 Feb 2008 08:11:26 -0500 Received: from d06nrmr1407.portsmouth.uk.ibm.com (d06nrmr1407.portsmouth.uk.ibm.com [9.149.38.185]) by mtagate1.uk.ibm.com (8.13.8/8.13.8) with ESMTP id m1BDBP4h102414 for ; Mon, 11 Feb 2008 13:11:25 GMT Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by d06nrmr1407.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1BDBPxd1196140 for ; Mon, 11 Feb 2008 13:11:25 GMT Received: from d06av04.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m1BDBIrg002189 for ; Mon, 11 Feb 2008 13:11:20 GMT Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: 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? Anthony, Dor, are you ok with that change? -- 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: