Re: [Qemu-devel] [PATCH v8 11/12] vfio: register aer resume notification handler for aer resume

[Zhou Jie]

Hi Alex,

> > > > I will use workable state support flag
> > > > to let user know whether the kenerl support block feature.
> > > > And make configure space writing and ioctl function blocked.
> > >
> > > And what of my suggestion that a user may desire to poll the state of
> > > the device?
> > I will also add a poll function to vfio_fops.
>
> Can you explain how this will work?  I was only suggesting that one of
> the flag bits in vfio_device_info be allocated to report the current
> state of blocking and the user could poll by repeatedly calling the
> DEVICE_INFO ioctl.  Are you thinking of using POLLOUT/POLLIN?  I'm not
> sure if those are a perfect match since it's really only the PCI config
> region and a few ioctls where access is blocked, other operations may
> proceed normally.
Sorry, I had misunderstood your meaning.
I will use one of the flag bits in vfio_device_info to
 report the current state of blocking.

> > The following code will be modified.
> > 1. vfio_pci_ioctl
> >     add a flag in vfio_device_info for workable_state support
> > 2. vfio_pci_ioctl
> >     During err occurs and resume:
> >     if (cmd == VFIO_DEVICE_SET_IRQS || VFIO_DEVICE_RESET
> >     || VFIO_DEVICE_GET_PCI_HOT_RESET_INFO || VFIO_DEVICE_PCI_HOT_RESET)
> >     block for workable_state clearing
> > 3. vfio_pci_write
> >     During err occurs and resume:
> >     block write to configure space
> > 4. vfio_pci_aer_err_detected
> >     Set workable_state to false in "struct vfio_pci_device"
> >     teardown the interrupt
> > 5. vfio_pci_aer_resume
> >     Set workable_state to true in "struct vfio_pci_device"
> > 6. vfio_fops
> >     Add poll function
>
> I would still suggest that the name "workable_state" is quite vague.
> Something like aer_error_in_progress is much more specific.  Thanks,
OK, I will alter the name.

Sincerely
Zhou Jie