On 3/9/25 01:08, Aneesh Kumar K.V wrote:
Dan Williams <dan.j.williams@xxxxxxxxx> writes:The PCIe 7.0 specification, section 11, defines the Trusted Execution Environment (TEE) Device Interface Security Protocol (TDISP). This protocol definition builds upon Component Measurement and Authentication (CMA), and link Integrity and Data Encryption (IDE). It adds support for assigning devices (PCI physical or virtual function) to a confidential VM such that the assigned device is enabled to access guest private memory protected by technologies like Intel TDX, AMD SEV-SNP, RISCV COVE, or ARM CCA. The "TSM" (TEE Security Manager) is a concept in the TDISP specification of an agent that mediates between a "DSM" (Device Security Manager) and system software in both a VMM and a confidential VM. A VMM uses TSM ABIs to setup link security and assign devices. A confidential VM uses TSM ABIs to transition an assigned device into the TDISP "RUN" state and validate its configuration. From a Linux perspective the TSM abstracts many of the details of TDISP, IDE, and CMA. Some of those details leak through at times, but for the most part TDISP is an internal implementation detail of the TSM. CONFIG_PCI_TSM adds an "authenticated" attribute and "tsm/" subdirectory to pci-sysfs. Consider that the TSM driver may itself be a PCI driver. Userspace can watch for the arrival of a "TSM" device, /sys/class/tsm/tsm0/uevent KOBJ_CHANGE, to know when the PCI core has initialized TSM services. The operations that can be executed against a PCI device are split into two mutually exclusive operation sets, "Link" and "Security" (struct pci_tsm_{link,security}_ops). The "Link" operations manage physical link security properties and communication with the device's Device Security Manager firmware. These are the host side operations in TDISP. The "Security" operations coordinate the security state of the assigned virtual device (TDI). These are the guest side operations in TDISP. Only link management operations are defined at this stage and placeholders provided for the security operations. The locking allows for multiple devices to be executing commands simultaneously, one outstanding command per-device and an rwsem synchronizes the implementation relative to TSM registration/unregistration events. Thanks to Wu Hao for his work on an early draft of this support. Cc: Lukas Wunner <lukas@xxxxxxxxx> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxx> Cc: Alexey Kardashevskiy <aik@xxxxxxx> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Co-developed-by: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx> Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>you dropped pci_tsm_doe_transfer from an earlier version of this patch in this series. Any reason for that?
yeah, me, it was rather useless wrapper. https://lore.kernel.org/r/68ae4a0c45650_75db10016@dwillia2-mobl4.notmuch thanks,
-aneesh
-- Alexey
