Re: [PATCH v3 12/13] PCI/TSM: support TDI related operations for host TSM driver

[Aneesh Kumar K.V <aneesh.kumar@kernel.org>]

Jason Gunthorpe <jgg@nvidia.com> writes:

> On Wed, May 28, 2025 at 01:42:25PM -0300, Jason Gunthorpe wrote:
>> > +int iommufd_vdevice_tsm_bind_ioctl(struct iommufd_ucmd *ucmd)
>> > +{
>> > +	struct iommu_vdevice_id *cmd = ucmd->cmd;
>> > +	struct iommufd_vdevice *vdev;
>> > +	int rc = 0;
>> > +
>> > +	vdev = container_of(iommufd_get_object(ucmd->ictx, cmd->vdevice_id,
>> > +					       IOMMUFD_OBJ_VDEVICE),
>> > +			    struct iommufd_vdevice, obj);
>> > +	if (IS_ERR(vdev))
>> > +		return PTR_ERR(vdev);
>> > +
>> > +	rc = tsm_bind(vdev->dev, vdev->viommu->kvm, vdev->id);
>> 
>> Yeah, that makes alot of sense now, you are passing in the KVM for the
>> VIOMMU and both the vBDF and pBDF to the TSM layer, that should be
>> enough for it to figure out what to do. The only other data would be
>> the TSM's VIOMMU handle..
>
> Actually it should also check that the viommu type is compatible with
> the TSM, somehow.
>
> The way I imagine this working is userspace would create a 
> IOMMU_VIOMMU_TYPE_TSM_VTD (for example) viommu object which will do a
> TSM call to setup the secure vIOMMU
>
> Then when you create a VDEVICE against the IOMMU_VIOMMU_TYPE_TSM_VTD
> it will do a TSM call to create the secure vPCI function attached to
> the vIOMMU and register the vBDF. [1]
>

Don’t we create the vdevice before the guest starts? If I
understand correctly, we expect tsm_bind to be triggered by the guest’s
request—specifically, when it writes to /sys/bus/pci/devices/X/tsm/connect.

-aneesh