Re: [PATCH v2 11/13] Documentation: userspace-api: iommufd: Update EVENTQ_IOPF and EVENTQ_VIRQ

[Nicolin Chen <nicolinc@nvidia.com>]

On Wed, Dec 11, 2024 at 08:11:03AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@nvidia.com>
> > Sent: Wednesday, December 4, 2024 6:10 AM
> > 
> > With the introduction of the new objects, update the doc to reflect that.
> > 
> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> > ---
> >  Documentation/userspace-api/iommufd.rst | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> > 
> > diff --git a/Documentation/userspace-api/iommufd.rst
> > b/Documentation/userspace-api/iommufd.rst
> > index 70289d6815d2..798520d9344d 100644
> > --- a/Documentation/userspace-api/iommufd.rst
> > +++ b/Documentation/userspace-api/iommufd.rst
> > @@ -63,6 +63,14 @@ Following IOMMUFD objects are exposed to userspace:
> >    space usually has mappings from guest-level I/O virtual addresses to guest-
> >    level physical addresses.
> > 
> > +- IOMMUFD_OBJ_EVENTQ_IOPF, representing a software queue for an
> > HWPT_NESTED
> 
> now it can be used on paging hwpt too

Oh, that's why it's in the common path in the hwpt allocator...

Seems that we are missing its selftest coverage for paging hwpt?

> > +  reporting IO Page Fault using the IOMMU HW's PRI (Page Request
> > Interface).
> > +  This queue object provides user space an FD to poll the page fault events
> > +  and also to respond to those events. An EVENTQ_IOPF object must be
> > created
> > +  first to get a fault_id that could be then used to allocate an HWPT_NESTED
> > +  via the IOMMU_HWPT_ALLOC command setting
> > IOMMU_HWPT_FAULT_ID_VALID set in
> > +  its flags field.
> > +
> >  - IOMMUFD_OBJ_VIOMMU, representing a slice of the physical IOMMU
> > instance,
> >    passed to or shared with a VM. It may be some HW-accelerated
> > virtualization
> >    features and some SW resources used by the VM. For examples:
> > @@ -109,6 +117,15 @@ Following IOMMUFD objects are exposed to
> > userspace:
> >    vIOMMU, which is a separate ioctl call from attaching the same device to an
> >    HWPT_PAGING that the vIOMMU holds.
> > 
> > +- IOMMUFD_OBJ_EVENTQ_VIRQ, representing a software queue for
> > IOMMUFD_OBJ_VIOMMU
> > +  reporting its non-affiliated events, such as translation faults occurred to a
> 
> non-affiliated is only mentioned here. It's not a standard term in this
> area. Sticking to the later examples in 'such as' is straightforward.

OK.

> > +  nested stage-1 and HW-specific events/irqs e.g. events to invalidation
> > queues
> > +  that are assigned to VMs via vIOMMUs. This queue object provides user
> 
> vcmdq is not supported yet. add it later.

Ack.

Thanks
Nic