lkml.org 
[lkml]   [2023]   [Oct]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRE: [PATCH v4 01/17] iommu: Add hwpt_type with user_data for domain_alloc_user op
    Date
    > From: Liu, Yi L <yi.l.liu@intel.com>
    > Sent: Tuesday, October 17, 2023 4:52 PM
    >
    > On 2023/10/17 02:17, Nicolin Chen wrote:
    > > On Mon, Oct 16, 2023 at 08:54:07AM -0300, Jason Gunthorpe wrote:
    > >> On Mon, Oct 16, 2023 at 11:28:15AM +0800, Yi Liu wrote:
    > >>> On 2023/10/14 01:56, Nicolin Chen wrote:
    > >>>> On Fri, Oct 13, 2023 at 11:04:56AM -0300, Jason Gunthorpe wrote:
    > >>>>> On Fri, Oct 13, 2023 at 12:33:13PM +0800, Yi Liu wrote:
    > >>>>>
    > >>>>>> not really. Below the users of the struct iommu_user_data in my
    > current
    > >>>>>> iommufd_nesting branch. Only the domain_alloc_user op has type as
    > there
    > >>>>>> can be multiple vendor specific alloc data types. Basically, I'm ok to
    > >>>>>> make the change you suggested, just not sure if it is good to add type
    > >>>>>> as it is only needed by one path.
    > >>>>>
    > >>>>> I don't think we should ever have an opaque data blob without a type
    > >>>>> tag..
    > >>>>
    > >>>> I can add those "missing" data types, and then a driver will be
    > >>>> responsible for sanitizing the type along with the data_len.
    > >>>>
    > >>>> I notice that the enum iommu_hwpt_data_type in the posted patch
    > >>>> is confined to the alloc_user uAPI. Perhaps we should share it
    > >>>> with invalidate too:
    > >>>
    > >>> invalidation path does not need a type field today as the data
    > >>> type is vendor specific, vendor driver should know the data type
    > >>> when calls in.
    > >>
    > >> I'm not keen on that, what if a driver needs another type in the
    > >> future? You'd want to make the invalidation data format part of the
    > >> domain allocation?
    > >
    > > The invalidation data has hwpt_id so it's tied to a hwpt and its
    > > hwpt->domain. Would it be reasonable to have a different type of
    > > invalidation data for the same type of hwpt?
    >
    > this seems like what Jason asks. A type of hwpt can have two kinds
    > of invalidation data types. Is it really possible?
    >

    e.g. vhost-iommu may want its own vendor-agnostic format from
    previous discussion...
    \
     
     \ /
      Last update: 2023-10-17 11:30    [W:3.415 / U:0.128 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site