Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx> writes:
> On Tue, May 20, 2025 at 12:47:05PM +0530, Aneesh Kumar K.V wrote:
>> Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx> writes:
>>
>> > On Thu, May 15, 2025 at 10:47:31PM -0700, Dan Williams wrote:
>> >> From: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx>
>> >>
>> >> Add kAPIs pci_tsm_{bind,unbind,guest_req}() for PCI devices.
>> >>
>> >> pci_tsm_bind/unbind() are supposed to be called by kernel components
>> >> which manages the virtual device. The verb 'bind' means VMM does extra
>> >> configurations to make the assigned device ready to be validated by
>> >> CoCo VM as TDI (TEE Device Interface). Usually these configurations
>> >> include assigning device ownership and MMIO ownership to CoCo VM, and
>> >> move the TDI to CONFIG_LOCKED TDISP state by LOCK_INTERFACE_REQUEST
>> >> TDISP message. The detailed operations are specific to platform TSM
>> >> firmware so need to be supported by vendor TSM drivers.
>> >>
>> >> pci_tsm_guest_req() supports a channel for CoCo VM to directly talk
>> >> to TSM firmware about further TDI operations after TDI is bound, e.g.
>> >> get device interface report, certifications & measurements. So this kAPI
>> >> is supposed to be called from KVM vmexit handler.
>> >
>> > To clarify, this commit message is staled. We are proposing existing to
>> > QEMU, then pass to TSM through IOMMUFD VDEVICE.
>> >
>>
>> Can you share the POC code/git repo implementing that? I am looking for
>> pci_tsm_bind()/pci_tsm_unbind() example usage.
>
> The usage of these kAPIs should be in IOMMUFD, that's what I'm doing for
> Stage 2 patchset. I need to rebase this series, adopt suggestions from
> Jason, and make TDX Connect work to verify, so need more time...
>
Since the bind/unbind operations are PCI-specific callbacks, and iommufd
doesn’t seem to have a PCI-specific abstraction layer (unlike vfio,
which uses vfio_pci.c), I’m wondering how iommufd intends to support
PCI-specific TSM binding. Will there be a new interface for this, or is
it expected to hook into something existing?
-aneesh
