RE: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs
From: Liu, Yi L
Date: Thu Apr 01 2021 - 14:21:07 EST
> From: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> Sent: Thursday, April 1, 2021 8:05 PM
[...]
>
> Also wondering about:
>
> * Querying IOMMU nesting capabilities before binding page tables (which
> page table formats are supported?). We were planning to have a VFIO cap,
> but I'm guessing we need to go back to the sysfs solution?
I think it can also be with /dev/ioasid.
>
> * Invalidation, probably an ioasid_fd ioctl?
yeah, if we are doing bind/unbind_pagtable via ioasid_fd, then yes,
invalidation should go this way as well. This is why I worried it may
fail to meet the requirement from you and Eric.
> * Page faults, page response. From and to devices, and don't necessarily
> have a PASID. But needed by vdpa as well, so that's also going through
> /dev/ioasid?
page faults should still be per-device, but the fault event fd may be stored
in /dev/ioasid. page response would be in /dev/ioasid just like invalidation.
Regards,
Yi Liu
>
> Thanks,
> Jean