[PATCH v2 09/22] iommufd/viommu: Introduce IOMMUFD_OBJ_VCMDQ and its related struct

[Nicolin Chen]

On Mon, Apr 28, 2025 at 09:09:19AM +0800, Baolu Lu wrote:
> On 4/26/25 13:58, Nicolin Chen wrote:
> > Add a new IOMMUFD_OBJ_VCMDQ with an iommufd_vcmdq structure, representing
> > a command queue type of physical HW passed to a user space VM. This vCMDQ
> > object, is a subset of vIOMMU resources of a physical IOMMU's, such as:
> >   - NVIDIA's virtual command queue
> >   - AMD vIOMMU's command buffer
> > 
> > Inroduce a struct iommufd_vcmdq and its allocator iommufd_vcmdq_alloc().
> > Also add a pair of viommu ops for iommufd to forward user space ioctls to
> > IOMMU drivers.
> > 
> > Signed-off-by: Nicolin Chen<nicolinc at nvidia.com>
> 
> Reviewed-by: Lu Baolu <baolu.lu at linux.intel.com>
> 
> with a small nit below ...
> 
> > ---
> >   include/linux/iommufd.h | 35 +++++++++++++++++++++++++++++++++++
> >   1 file changed, 35 insertions(+)
> > 
> > diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
> > index ef0d3c4765cf..e91381aaec5a 100644
> > --- a/include/linux/iommufd.h
> > +++ b/include/linux/iommufd.h
> > @@ -37,6 +37,7 @@ enum iommufd_object_type {
> >   	IOMMUFD_OBJ_VIOMMU,
> >   	IOMMUFD_OBJ_VDEVICE,
> >   	IOMMUFD_OBJ_VEVENTQ,
> > +	IOMMUFD_OBJ_VCMDQ,
> >   #ifdef CONFIG_IOMMUFD_TEST
> >   	IOMMUFD_OBJ_SELFTEST,
> >   #endif
> > @@ -112,6 +113,14 @@ struct iommufd_vdevice {
> >   	u64 id; /* per-vIOMMU virtual ID */
> >   };
> > +struct iommufd_vcmdq {
> > +	struct iommufd_object obj;
> > +	struct iommufd_ctx *ictx;
> > +	struct iommufd_viommu *viommu;
> > +	dma_addr_t addr;
> 
> It's better to add a comment to state that @addr is a guest physical
> address. Or not?

Yea. Let's add one:

	dma_addr_t addr; /* in guest physical address space */

Thanks
Nicolin