Re: [Qemu-devel] [PATCH 10/12] virtio-net: multiqueue support

[Jason Wang <jasowang@redhat.com>]

On Wednesday, January 09, 2013 11:26:33 PM Jason Wang wrote:
> On 01/09/2013 06:01 PM, Wanlong Gao wrote:
> > On 01/09/2013 05:30 PM, Jason Wang wrote:
> >> On 01/09/2013 04:23 PM, Wanlong Gao wrote:
> >>> On 01/08/2013 06:14 PM, Jason Wang wrote:
> >>>> On 01/08/2013 06:00 PM, Wanlong Gao wrote:
> >>>>> On 01/08/2013 05:51 PM, Jason Wang wrote:
> >>>>>> On 01/08/2013 05:49 PM, Wanlong Gao wrote:
> >>>>>>> On 01/08/2013 05:29 PM, Jason Wang wrote:
> >>>>>>>> On 01/08/2013 05:07 PM, Wanlong Gao wrote:
> >>>>>>>>> On 12/28/2012 06:32 PM, Jason Wang wrote:
> >>>>>>>>>> +    } else if (nc->peer->info->type != 
> >>>>>>>>>> NET_CLIENT_OPTIONS_KIND_TAP) {
> >>>>>>>>>> +        ret = -1;
> >>>>>>>>>> +    } else {
> >>>>>>>>>> +        ret = tap_detach(nc->peer);
> >>>>>>>>>> +    }
> >>>>>>>>>> +
> >>>>>>>>>> +    return ret;
> >>>>>>>>>> +}
> >>>>>>>>>> +
[...]
> >>> I got guest kernel panic when using this way and set queues=4.
> >> 
> >> Does it happens w/o or w/ a fd parameter? What's the qemu command line?
> >> Did you meet it during boot time?
> > 
> > The QEMU command line is
> > 
> > /work/git/qemu/x86_64-softmmu/qemu-system-x86_64 -name f17 -M pc-0.15
> > -enable-kvm -m 3096 \ -smp 4,sockets=4,cores=1,threads=1 \
> > -uuid c31a9f3e-4161-c53a-339c-5dc36d0497cb -no-user-config -nodefaults \
> > -chardev
> > socket,id=charmonitor,path=/var/lib/libvirt/qemu/f17.monitor,server,nowai
> > t \ -mon chardev=charmonitor,id=monitor,mode=control \
> > -rtc base=utc -no-shutdown \
> > -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
> > -device
> > virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0xb,num_queues=4,hotplug=on \
> > -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 \
> > -drive file=/vm/f17.img,if=none,id=drive-virtio-disk0,format=qcow2 \
> > -device
> > virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk0,id=vi
> > rtio-disk0,bootindex=1 \ -drive
> > file=/vm2/f17-kernel.img,if=none,id=drive-virtio-disk1,format=qcow2 \
> > -device
> > virtio-blk-pci,scsi=off,bus=pci.0,addr=0x8,drive=drive-virtio-disk1,id=vi
> > rtio-disk1 \ -drive
> > file=/vm/virtio-scsi/scsi3.img,if=none,id=drive-scsi0-0-2-0,format=raw \
> > -device
> > scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=2,drive=drive-scsi0-0-2-0,id=
> > scsi0-0-2-0,removable=on \ -drive
> > file=/vm/virtio-scsi/scsi4.img,if=none,id=drive-scsi0-0-3-0,format=raw \
> > -device
> > scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=3,drive=drive-scsi0-0-3-0,id=
> > scsi0-0-3-0 \ -drive
> > file=/vm/virtio-scsi/scsi1.img,if=none,id=drive-scsi0-0-0-0,format=raw \
> > -device
> > scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=
> > scsi0-0-0-0 \ -drive
> > file=/vm/virtio-scsi/scsi2.img,if=none,id=drive-scsi0-0-1-0,format=raw \
> > -device
> > scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-1-0,id=
> > scsi0-0-1-0 \ -chardev pty,id=charserial0 -device
> > isa-serial,chardev=charserial0,id=serial0 \ -chardev
> > file,id=charserial1,path=/vm/f17.log \
> > -device isa-serial,chardev=charserial1,id=serial1 \
> > -device usb-tablet,id=input0 -vga std \
> > -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7 \
> > -netdev tap,id=hostnet0,vhost=on,queues=4 \
> > -device
> > virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:ce:7b:29,bus=pci.0,ad
> > dr=0x3 \ -monitor stdio
> > 
> > I got panic just after booting the system, did nothing,  waited for a
> > while, the guest panicked.
> > 
> > [   28.053004] BUG: soft lockup - CPU#1 stuck for 23s! [ip:592]
> > [   28.053004] Modules linked in: ip6t_REJECT nf_conntrack_ipv6
> > nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables uinput
> > joydev microcode virtio_balloon pcspkr virtio_net i2c_piix4 i2c_core
> > virtio_scsi virtio_blk floppy [   28.053004] CPU 1
> > [   28.053004] Pid: 592, comm: ip Not tainted 3.8.0-rc1-net+ #3 Bochs
> > Bochs
> > [   28.053004] RIP: 0010:[<ffffffff8137a9ab>]  [<ffffffff8137a9ab>]
> > virtqueue_get_buf+0xb/0x120 [   28.053004] RSP: 0018:ffff8800bc913550 
> > EFLAGS: 00000246
> > [   28.053004] RAX: 0000000000000000 RBX: ffff8800bc49c000 RCX:
> > ffff8800bc49e000 [   28.053004] RDX: 0000000000000000 RSI:
> > ffff8800bc913584 RDI: ffff8800bcfd4000 [   28.053004] RBP:
> > ffff8800bc913558 R08: ffff8800bcfd0800 R09: 0000000000000000 [  
> > 28.053004] R10: ffff8800bc49c000 R11: ffff880036cc4de0 R12:
> > ffff8800bcfd4000 [   28.053004] R13: ffff8800bc913558 R14:
> > ffffffff8137ad73 R15: 00000000000200d0 [   28.053004] FS: 
> > 00007fb27a589740(0000) GS:ffff8800c1480000(0000) knlGS:0000000000000000 [
> >   28.053004] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [   28.053004] CR2: 0000000000640530 CR3: 00000000baeff000 CR4:
> > 00000000000006e0 [   28.053004] DR0: 0000000000000000 DR1:
> > 0000000000000000 DR2: 0000000000000000 [   28.053004] DR3:
> > 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [  
> > 28.053004] Process ip (pid: 592, threadinfo ffff8800bc912000, task
> > ffff880036da2e20) [   28.053004] Stack:
> > [   28.053004]  ffff8800bcfd0800 ffff8800bc913638 ffffffffa003e9bb
> > ffff8800bc913656 [   28.053004]  0000000100000002 ffff8800c17ebb08
> > 000000500000ff10 ffffea0002f244c0 [   28.053004]  0000000200000582
> > 0000000000000000 0000000000000000 ffffea0002f244c0 [   28.053004] Call
> > Trace:
> > [   28.053004]  [<ffffffffa003e9bb>]
> > virtnet_send_command.constprop.26+0x24b/0x270 [virtio_net] [   28.053004]
> >  [<ffffffff812ed963>] ? sg_init_table+0x23/0x50
> > [   28.053004]  [<ffffffffa0040629>] virtnet_set_rx_mode+0x99/0x300
> > [virtio_net] [   28.053004]  [<ffffffff8152306f>]
> > __dev_set_rx_mode+0x5f/0xb0
> > [   28.053004]  [<ffffffff815230ef>] dev_set_rx_mode+0x2f/0x50
> > [   28.053004]  [<ffffffff815231b7>] __dev_open+0xa7/0xf0
> > [   28.053004]  [<ffffffff81523461>] __dev_change_flags+0xa1/0x180
> > [   28.053004]  [<ffffffff815235f8>] dev_change_flags+0x28/0x70
> > [   28.053004]  [<ffffffff8152ff20>] do_setlink+0x3b0/0xa50
> > [   28.053004]  [<ffffffff812fb6b1>] ? nla_parse+0x31/0xe0
> > [   28.053004]  [<ffffffff815325de>] rtnl_newlink+0x36e/0x580
> > [   28.053004]  [<ffffffff811355cc>] ? get_page_from_freelist+0x37c/0x730
> > [   28.053004]  [<ffffffff81531e13>] rtnetlink_rcv_msg+0x113/0x2f0
> > [   28.053004]  [<ffffffff8117d973>] ?
> > __kmalloc_node_track_caller+0x63/0x1c0 [   28.053004] 
> > [<ffffffff8151526b>] ? __alloc_skb+0x8b/0x2a0
> > [   28.053004]  [<ffffffff81531d00>] ? __rtnl_unlock+0x20/0x20
> > [   28.053004]  [<ffffffff8154b571>] netlink_rcv_skb+0xb1/0xc0
> > [   28.053004]  [<ffffffff8152ea05>] rtnetlink_rcv+0x25/0x40
> > [   28.053004]  [<ffffffff8154ae91>] netlink_unicast+0x1a1/0x220
> > [   28.053004]  [<ffffffff8154b211>] netlink_sendmsg+0x301/0x3c0
> > [   28.053004]  [<ffffffff81508530>] sock_sendmsg+0xb0/0xe0
> > [   28.053004]  [<ffffffff8113a45b>] ? lru_cache_add_lru+0x3b/0x60
> > [   28.053004]  [<ffffffff811608b7>] ? page_add_new_anon_rmap+0xc7/0x180
> > [   28.053004]  [<ffffffff81509efc>] __sys_sendmsg+0x3ac/0x3c0
> > [   28.053004]  [<ffffffff8162e47c>] ? __do_page_fault+0x23c/0x4d0
> > [   28.053004]  [<ffffffff8115c9ef>] ? do_brk+0x1ff/0x370
> > [   28.053004]  [<ffffffff8150bec9>] sys_sendmsg+0x49/0x90
> > [   28.053004]  [<ffffffff81632d59>] system_call_fastpath+0x16/0x1b
> > [   28.053004] Code: 04 0f ae f0 48 8b 47 50 5d 0f b7 50 02 66 39 57 64 0f
> > 94 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41
> > 54 <53> 80 7f 59 00 48 89 fb 0f 85 90 00 00 00 48 8b 47 50 0f b7 50
> > 
> > 
> > The QEMU tree I used is git://github.com/jasowang/qemu.git
> 
> Thanks a lot, will try to reproduce my self tomorrow. From the
> calltrace, looks like we send a command to a rx/tx queue.

Right, the virtqueue that will not be used by single queue were initialized.
Please try to following patch or use the my qemu.git with this fix in github.

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 8b4f079..cfd9af1 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -186,7 +186,7 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
             continue;
         }
 
-        if (virtio_net_started(n, status) && !q->vhost_started) {
+        if (virtio_net_started(n, queue_status) && !q->vhost_started) {
             if (q->tx_timer) {
                 qemu_mod_timer(q->tx_timer,
                                qemu_get_clock_ns(vm_clock) + n->tx_timeout);
@@ -545,7 +545,8 @@ static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
 
     if (s.virtqueue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
         s.virtqueue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
-        s.virtqueue_pairs > n->max_queues) {
+        s.virtqueue_pairs > n->max_queues ||
+        !n->multiqueue) {
         return VIRTIO_NET_ERR;
     }
 
@@ -1026,19 +1027,15 @@ static void virtio_net_tx_bh(void *opaque)
 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int ctrl)
 {
     VirtIODevice *vdev = &n->vdev;
-    int i;
+    int i, max = multiqueue ? n->max_queues : 1;
 
     n->multiqueue = multiqueue;
 
-    if (!multiqueue) {
-        n->max_queues = 1;
-    }
-
     for (i = 2; i <= n->max_queues * 2 + 1; i++) {
         virtio_del_queue(vdev, i);
     }
 
-    for (i = 1; i < n->max_queues; i++) {
+    for (i = 1; i < max; i++) {
         n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
         if (n->vqs[i].tx_timer) {
             n->vqs[i].tx_vq =
-- 
1.7.1


Thanks



> 
> > Thanks,
> > Wanlong Gao
> > 
[...]