> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Tuesday, December 12, 2023 10:40 PM > > On Tue, Dec 12, 2023 at 01:45:16PM +0000, Liu, Yi L wrote: > > > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > > Sent: Monday, December 11, 2023 9:22 PM > > > > > > On Mon, Dec 11, 2023 at 03:53:40PM +0800, Yi Liu wrote: > > > > > > > > > From that thread Jason mentioned to make the invalidation format > > > > > > part of domain allocation. If that is the direction to go then there > > > > > > won't be multiple invalidation formats per hwpt. The user should > > > > > > create multiple hwpt's per invalidation format (though mixing > > > > > > formats in one virtual platform is very unlikely)? > > > > > > > > > > I think we could do either, but I have a vauge cleanness preference > > > > > that the enums are just different? That would follow a pretty typical > > > > > pattern for a structure tag to reflect the content of the structure. > > > > > > > > Is this still following the direction to make the invalidation format > > > > part of domain allocation? > > > > > > I think you should make it seperate > > > > Sure. I'll add a separate enum for cache invalidation format. Just to > > see if it is good to pass down the invalidation format in the hwpt > > alloc path? So iommu driver can check if the invalidation format > > can be used for the hwpt to be allocated. > > I would skip it in the invalidation. If necessary drivers can push a 0 > length invalidation to do 'try and fail' discovery of supported types. I think you mean keep passing the req_type in cache invalidation path instead of the way I proposed. For the 'try and fail' discovery, we should allow a zero-length array, is it? If the req_type is supported by the iommu driver, then return successful, otherwise fail the ioctl. Is it? Regards, Yi Liu
