Re: [RFC 00/18] vfio: Adopt iommufd

zhangfei.gao
2022-05-11T14:17:46Z

On 2022/5/10 下午10:08, Yi Liu wrote:
> On 2022/5/10 20:45, Jason Gunthorpe wrote:
>> On Tue, May 10, 2022 at 08:35:00PM +0800, Zhangfei Gao wrote:
>>> Thanks Yi and Eric,
>>> Then will wait for the updated iommufd kernel for the PCI MMIO region.
>>>
>>> Another question,
>>> How to get the iommu_domain in the ioctl.
>>
>> The ID of the iommu_domain (called the hwpt) it should be returned by
>> the vfio attach ioctl.
>
> yes, hwpt_id is returned by the vfio attach ioctl and recorded in
> qemu. You can query page table related capabilities with this id.
>
> https://lore.kernel.org/kvm/20220414104710.28534-16-yi.l.liu@intel.com/
>
Thanks Yi,

Do we use iommufd_hw_pagetable_from_id in kernel?

The qemu send hwpt_id via ioctl.
Currently VFIOIOMMUFDContainer has hwpt_list,
Which member is good to save hwpt_id, IOMMUTLBEntry?

In kernel ioctl: iommufd_vfio_ioctl
@dev: Device to get an iommu_domain for
iommufd_hw_pagetable_from_id(struct iommufd_ctx *ictx, u32 pt_id, struct
device *dev)
But iommufd_vfio_ioctl seems no para dev?

Thanks