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

[Chen Fan]

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 <address@hidden>
> > > > ---
> > > >    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) {
>
>
>
> .