Re: [Qemu-devel] [RFC v9 14/18] vfio: improve vfio_pci_hot_reset to support more case

[Chen Fan <chen.fan.fnst@cn.fujitsu.com>]

On 06/16/2015 10:08 PM, Alex Williamson wrote:
> On Tue, 2015-06-16 at 16:10 +0800, Chen Fan wrote:
>> On 06/10/2015 05:24 AM, Alex Williamson wrote:
>>> On Tue, 2015-06-09 at 11:37 +0800, Chen Fan wrote:
>>>> the vfio_pci_hot_reset differentiate the single and multi in-used
>>>> devices for reset. but sometimes we own the group without any devices,
>>>> that also should support hot reset.
>>> Nope, did you try it?  It can be done, but the group still needs to be
>>> connected to a container for isolation.
>> I'm sorry for that. because I have no such host in hand. but I think if
>> we can keep connect container for each affected group, we also able
>> to use this method to do host bus reset.
>
> All you need is a dual-port card with isolation, which includes all
> Intel 1G NICs (igb & e1000e) as of the quirks that are currently in
> linux-next to be pushed for v4.2.  Intel 10G NICs are already quirked
> upstream.  There are certainly ways to fake isolation for testing as
> well.  Thanks,

I just have a Intel Corporation 82576 dual-port card, but how can I fake
isolation group for this card in linux-next kernel? can you tell me the
document link?

Thanks,
Chen


>
> Alex
>
>>>> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
>>>> ---
>>>>    hw/vfio/pci.c | 11 +++++++++++
>>>>    1 file changed, 11 insertions(+)
>>>>
>>>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>>>> index a4e8658..6507f39 100644
>>>> --- a/hw/vfio/pci.c
>>>> +++ b/hw/vfio/pci.c
>>>> @@ -3398,6 +3398,7 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
>>>>            PCIHostDeviceAddress host;
>>>>            VFIOPCIDevice *tmp;
>>>>            VFIODevice *vbasedev_iter;
>>>> +        bool found;
>>>>    
>>>>            host.domain = devices[i].segment;
>>>>            host.bus = devices[i].bus;
>>>> @@ -3427,6 +3428,7 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
>>>>                goto out;
>>>>            }
>>>>    
>>>> +        found = false;
>>>>            /* Prep dependent devices for reset and clear our marker. */
>>>>            QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
>>>>                if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
>>>> @@ -3438,12 +3440,21 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
>>>>                        ret = -EINVAL;
>>>>                        goto out_single;
>>>>                    }
>>>> +                found = true;
>>>>                    vfio_pci_pre_reset(tmp);
>>>>                    tmp->vbasedev.needs_reset = false;
>>>>                    multi = true;
>>>>                    break;
>>>>                }
>>>>            }
>>>> +
>>>> +        /*
>>>> +         * If we own the group but does not own the device, we also
>>>> +         * should call hot reset with multi.
>>>> +         */
>>>> +        if (!single && !found) {
>>>> +            multi = true;
>>>> +        }
>>>>        }
>>>>    
>>>>        if (!single && !multi) {
>>>
>>>
>>>
>
>
>
> .
>