> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Sent: Friday, March 24, 2023 5:25 PM > > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Sent: Thursday, March 23, 2023 8:02 PM > > > > On Thu, Mar 23, 2023 at 03:15:20AM +0000, Liu, Yi L wrote: > > > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > > > Sent: Wednesday, March 22, 2023 9:43 PM > > > > > > > > On Wed, Mar 22, 2023 at 01:33:09PM +0000, Liu, Yi L wrote: > > > > > > > > > Thanks. So this new _INFO only reports a limited scope instead of > > > > > the full list of affected devices. Also, it is not static scope since device > > > > > may be opened just after the _INFO returns. > > > > > > > > Yes, it would be simplest for qemu to do the query after it gains a > > > > new dev_id and then it can add the new dev_id with the correct reset > > > > group. > > > > > > I see. QEMU can decide. For now, it seems like QEMU doesn't store > > > such the info return by the existing _INFO ioctl. It is used in the hot > > > reset helper and freed before it returns. Though, I'm not sure whether > > > QEMU will store the dev_id info returned by the new _INFO. Perhaps > > > Alex can give some guidance. > > > > That seems a bit confusing, qemu should take the reset group > > information and encode it so that the guest can know it as well. > > > > If all it does is blindly invoke the hot_reset with the right > > parameters then what was the point of all this discussion? > > > > > btw. Another question about this new _INFO ioctl. If there are affected > > > devices that have not been bound to vfio driver yet, should this new > _INFO > > > ioctl fail all the same with EPERM? > > > > Yeah, it should EPERM the same as the normal hot reset if it can't > > marshal the device list. > > Hi Jason, Alex, > > I got a draft patch to add the new _INFO? It checks if all the affected devices > are in the dev_set, and then gets the dev_id of all the opened devices within > the dev_set. There is still one thing not quite clear. It is the noiommu mode. > In this mode, there is no iommufd bind, so no dev_id. For now, I just fail this > new _INFO ioctl if there is no iommufd_device. Hence, this new _INFO is not > available for users that operating in noiommu mode. Is this acceptable? The latest _INFO ioctl is in below link. https://lore.kernel.org/kvm/20230327093458.44939-11-yi.l.liu@xxxxxxxxx/
