Re: error when pass through device to guest with qemu-xen-dir-remote

[Anthony PERARD <anthony.perard@citrix.com>]

On Wed, Sep 19, 2012 at 1:06 AM, Zhang, Yang Z <yang.z.zhang@intel.com> wrote:
> Anthony PERARD wrote on 2012-09-18:
>>
>> Hi,
>>
>> So, we'll have to add a check in the unplug code of qemu to ignore
>> passthrough devices.
>>
>> Here is a patches, I did not test it.
>>
>> diff --git a/hw/xen_platform.c b/hw/xen_platform.c
>> index 0d6c2ff..2d3978e 100644
>> --- a/hw/xen_platform.c
>> +++ b/hw/xen_platform.c
>> @@ -85,8 +85,10 @@ static void log_writeb ...
>>
>>   static void unplug_nic(PCIBus *b, PCIDevice *d, void *o)
>>   {
>> +    /* We have to ignore passthrough devices */
>>       if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
>> -            PCI_CLASS_NETWORK_ETHERNET) {
>> +            PCI_CLASS_NETWORK_ETHERNET
>> +        && strcmp(d->name, "xen-pci-passthrough") != 0) {
>>           qdev_free(&d->qdev);
>>       }
>>   }
>
> In old qemu, we will free the invalid NIC through this function. And it will fail w/ your change. Shouldn't we follow the old logic?

I don't understand. Are you arguing this patch or the function it self?

My change is fine and follow the old logic: do not do anything for a
passthrough device.

I now have tested the change, and QEMU work as espected, it will
unplug the emulated NIC, and ignore any passthrough devices. So the
guest can the passthroughed NIC.

Thanks,

-- 
Anthony PERARD