Re: [PATCH v2 07/19] PCI/TSM: Add Device Security (TVM Guest) ACCEPT operation support

[Baolu Lu <baolu.lu@linux.intel.com>]

On 3/3/26 08:01, Dan Williams wrote:
> The final operation of the PCIe Trusted Execution Environment (TEE) Device
> Interface Security Protocol (TDISP) is asking the TEE Security Manager
> (TEE) to enable private DMA and MMIO.
> 
> The story so far in the security lifecycle of the device is that the VMM
> setup an SPDM session and link encryption with the device's physical
> function0. The VMM then assigned either that physical function or other
> virtual function of that device to a VM. The VM asked the TSM to transition
> the device from TDISP UNLOCKED->LOCKED. With the device LOCKED the VM
> validated signed fresh device evidence and expected MMIO mappings.
> 
> The VM now accepts the device to transition it from LOCKED to RUN and tell
> the TSM to unblock DMA to VM private memory.
> 
> Implement a sysfs trigger to flip the device to private operation and plumb
> that to a 'struct pci_tsm_ops::accept()' operation.
> 
> Co-developed-by: Xu Yilun<yilun.xu@linux.intel.com>
> Signed-off-by: Xu Yilun<yilun.xu@linux.intel.com>
> Co-developed-by: Aneesh Kumar K.V (Arm)<aneesh.kumar@kernel.org>
> Signed-off-by: Aneesh Kumar K.V (Arm)<aneesh.kumar@kernel.org>
> Signed-off-by: Dan Williams<dan.j.williams@intel.com>
> ---
>   drivers/pci/Kconfig                     |  2 +
>   Documentation/ABI/testing/sysfs-bus-pci | 13 +++++
>   include/linux/pci-tsm.h                 |  7 ++-
>   drivers/pci/tsm.c                       | 69 ++++++++++++++++++++++++-
>   4 files changed, 88 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index e3f848ffb52a..c45c6b978e1d 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -127,6 +127,8 @@ config PCI_IDE
>   
>   config PCI_TSM
>   	bool "PCI TSM: Device security protocol support"
> +	depends on ARCH_HAS_CC_PLATFORM
> +	select CONFIDENTIAL_DEVICES
>   	select PCI_IDE
>   	select PCI_DOE
>   	select TSM
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index 1ed77b9402a6..c2a5c4fe9373 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -732,3 +732,16 @@ Description:
>   		'lock' to teardown the connection. Writes fail with EBUSY if
>   		this device is bound to a driver. This is a "devsec" TSM
>   		attribute, see Documentation/ABI/testing/sysfs-class-tsm.
> +
> +What:		/sys/bus/pci/devices/.../tsm/accept
> +Contact:	linux-coco@lists.linux.dev
> +Description:
> +		(RW) Write "1" (or any boolean "true" string) to this file to
> +		request that TSM transition the device from the TDISP LOCKED
> +		state to the RUN state and arrange the for the secure IOMMU to

Nit: remove the typo extra 'the'

"...and arrange for the secure IOMMU to..."

> +		accept requests with T=1 in the PCIe packet header (TLP)
> +		targeting private memory. Per TDISP the only exits from the RUN
> +		state are via an explicit unlock request or an event that
> +		transitions the device to the ERROR state. Writes fail with
> +		EBUSY if this device is bound to a driver. This is a "devsec"
> +		TSM attribute, see Documentation/ABI/testing/sysfs-class-tsm.

Thanks,
baolu