Re: [Qemu-devel] [RFC PATCH] spapr: add ibmveth to the supported network adapters list

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 10/28/2013 05:03 AM, Alexander Graf wrote:
> 
> On 10.10.2013, at 20:09, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
> 
>> The problem is that "-net nic,model=?" does not print "ibmveth" in
>> the list while it is actually supported.
>>
>> Most of the QEMU emulated network devices are PCI but "ibmveth"
>> (a.k.a. spapr-vlan) is not. However with "-net nic,model=?", QEMU prints
>> only PCI devices in the list, even if it does not say that the list is
>> all about PCI devices.
>>
>> This adds "?"/"help" handling in spapr.c and adds "ibmveth" in the beginning
>> of the list.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>>
>> This is an RFC patch.
>>
>> The other solutions could be:
>> 1. add "ibmveth" into pci_nic_models[] in hw/pci/pci.c but this would not
>> be correct as "ibmveth" is not PCI and it must appear only on pseries machine.
>>
>> 2. implemement short version of qdev_print_category_devices() and call it
>> with DEVICE_CATEGORY_NETWORK but that would print more devices than
>> pci_nic_init_nofail() can handle (vmxnet3, usb-bt-dongle).
>>
>> 3. fix qemu_check_nic_model() to specifically say that this is a list of
>> PCI devices and there might be some other devices which "-net nic,model+"
>> supports but there are not PCI but that could break compatibility (some
>> management software may rely on this exact string).
>>
>> 4. Reject the patch and just say that people must stop using "-net". Ok for me :)
>>
>> Since "-net" is kind of obsolete interface and does not seem to be extended ever,
>> the proposed patch does not look too ugly, does not it?
>> ---
>> hw/ppc/spapr.c | 15 +++++++++++++++
>> 1 file changed, 15 insertions(+)
>>
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index c0613e4..45ed3da 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -1276,6 +1276,21 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
>>
>>         if (strcmp(nd->model, "ibmveth") == 0) {
>>             spapr_vlan_create(spapr->vio_bus, nd);
>> +        } else if (is_help_option(nd->model)) {
>> +            static const char * const nic_models[] = {
>> +                "ibmveth",
>> +                "ne2k_pci",
>> +                "i82551",
>> +                "i82557b",
>> +                "i82559er",
>> +                "rtl8139",
>> +                "e1000",
>> +                "pcnet",
>> +                "virtio",
>> +                NULL
>> +            };
> 
> I don't like the idea of duplicating that list.

Neither do I :) But the list itself already looks quite ugly.

> Basically the list of supported -net models is incorrect today even on
> x86 where you can say -net nic,model=ne2k_isa. It really is only a list
> of PCI devices.


> I can think of a number of convoluted ways to fix this up, but I think
> that ignoring fully accuracy of the output of -net model=? is the most
> straight forward thing to do.

Does any of your "convoluted" ways include adding a new category
(DEVICE_CATEGORY_NETWORK_LEGACY?) into enum DeviceCategory, adding devices
from the list above and fixing qemu_show_nic_models() to show what is in
the category?

Or "-net" interface is "deprecated" and we do not want even touch it?



-- 
Alexey