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;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static void virtio_net_set_queues(VirtIONet *n)
>>>>>>>> +{
>>>>>>>> + int i;
>>>>>>>> +
>>>>>>>> + for (i = 0; i < n->max_queues; i++) {
>>>>>>>> + if (i < n->curr_queues) {
>>>>>>>> + assert(!peer_attach(n, i));
>>>>>>>> + } else {
>>>>>>>> + assert(!peer_detach(n, i));
>>>>>>> I got a assert here,
>>>>>>> qemu-system-x86_64: /work/git/qemu/hw/virtio-net.c:330: virtio_net_set_queues: Assertion `!peer_detach(n, i)' failed.
>>>>>>>
>>>>>>> Any thoughts?
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Wanlong Gao
>>>>>> Thanks for the testing, which steps or cases did you met this assertion,
>>>>>> migration, reboot or just changing the number of virtqueues?
>>>>> I use the 3.8-rc2 to test it again, I saw this tag has the multi-tap support.
>>>>>
>>>>> I just can't start the QEMU use -netdev tap,id=hostnet0,queues=2,fd=%d,fd=%d -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:ce:7b:29,bus=pci.0,addr=0x3
>>>>>
>>>>> I pre-opened two tap fds, did I missing something?
>>>> Nothing missed :) It should work.
>>>>
>>>> Could you please try not use fd=X and let qemu to create the file
>>>> descriptors by itself? Btw, how did you create the two tap fds?
>>> Can it create descriptors itself? I get
>>> qemu-system-x86_64: -netdev tap,id=hostnet0,queues=2: Device 'tap' could not be initialized
>> You need prepare an ifup script which default at /etc/qemu-ifup (like
>> following). Or you may try to add a script=no after:
>>
>> #!/bin/sh
>>
>> switch=kvmbr0
>>
>> /sbin/ifconfig $1 0.0.0.0 up
>> /usr/sbin/brctl addif $switch $1
>> /usr/sbin/brctl stp $switch off
>>
>> This will let qemu create a tap fd itself and make it to be connected to
>> a port of the bridge caled kvmbr0.
> But how to support multi-queue in this way?
Qemu will create the necessary multiqueue tap by itself, see patch 0/12.
> 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?
Thanks
>
> Thanks,
> Wanlong Gao
>
>>> I create the tap fd like this, and dup create the second fd, third fd, right?
>> The second and third fd should be created with TUNSETIFF with the same
>> tap_name also. Btw, you need to specify a IFF_MULTI_QUEUE flag to tell
>> the kernel you want to create a multiqueue tap device, otherwise the
>> second and third calling of TUNSETIFF will fail.
>>
>> Thanks
>>> int tap_fd = open("/dev/net/tun", O_RDWR);
>>> int vhost_fd = open("/dev/vhost-net", O_RDWR);
>>> char *tap_name = "tap";
>>> char cmd[2048];
>>> char brctl[256];
>>> char netup[256];
>>> struct ifreq ifr;
>>> if (tap_fd < 0) {
>>> printf("open tun device failed\n");
>>> return -1;
>>> }
>>> if (vhost_fd < 0) {
>>> printf("open vhost-net device failed\n");
>>> return -1;
>>> }
>>> memset(&ifr, 0, sizeof(ifr));
>>> memcpy(ifr.ifr_name, tap_name, sizeof(tap_name));
>>> ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
>>>
>>> /*
>>> * setup tap net device
>>> */
>>> if (ioctl(tap_fd, TUNSETIFF, &ifr) < 0) {
>>> printf("setup tap net device failed\n");
>>> return -1;
>>> }
>>>
>>> sprintf(brctl, "brctl addif virbr0 %s", tap_name);
>>> sprintf(netup, "ifconfig %s up", tap_name);
>>> system(brctl);
>>> system(netup);
>>>
>>> Thanks,
>>> Wanlong Gao
>>>
>>>
>>>> Thanks
>>>>> Thanks,
>>>>> Wanlong Gao
>>>>>
>>>>>>>> + }
>>>>>>>> + }
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int ctrl);
>>>>>>>> +
>>>>>>> --
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>>
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