1 files changed, 243 insertions, 0 deletions
diff --git a/include/linux/pci-tsm.h b/include/linux/pci-tsm.h
new file mode 100644
index 000000000000..a6435aba03f9
--- /dev/null
+++ b/include/linux/pci-tsm.h
@@ -0,0 +1,243 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PCI_TSM_H
+#define __PCI_TSM_H
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/sockptr.h>
+
+struct pci_tsm;
+struct tsm_dev;
+struct kvm;
+enum pci_tsm_req_scope;
+
+/*
+ * struct pci_tsm_ops - manage confidential links and security state
+ * @link_ops: Coordinate PCIe SPDM and IDE establishment via a platform TSM.
+ *	      Provide a secure session transport for TDISP state management
+ *	      (typically bare metal physical function operations).
+ * @devsec_ops: Lock, unlock, and interrogate the security state of the
+ *		function via the platform TSM (typically virtual function
+ *		operations).
+ *
+ * This operations are mutually exclusive either a tsm_dev instance
+ * manages physical link properties or it manages function security
+ * states like TDISP lock/unlock.
+ */
+struct pci_tsm_ops {
+	/*
+	 * struct pci_tsm_link_ops - Manage physical link and the TSM/DSM session
+	 * @probe: establish context with the TSM (allocate / wrap 'struct
+	 *	   pci_tsm') for follow-on link operations
+	 * @remove: destroy link operations context
+	 * @connect: establish / validate a secure connection (e.g. IDE)
+	 *	     with the device
+	 * @disconnect: teardown the secure link
+	 * @bind: bind a TDI in preparation for it to be accepted by a TVM
+	 * @unbind: remove a TDI from secure operation with a TVM
+	 * @guest_req: marshal TVM information and state change requests
+	 *
+	 * Context: @probe, @remove, @connect, and @disconnect run under
+	 * pci_tsm_rwsem held for write to sync with TSM unregistration and
+	 * mutual exclusion of @connect and @disconnect. @connect and
+	 * @disconnect additionally run under the DSM lock (struct
+	 * pci_tsm_pf0::lock) as well as @probe and @remove of the subfunctions.
+	 * @bind, @unbind, and @guest_req run under pci_tsm_rwsem held for read
+	 * and the DSM lock.
+	 */
+	struct_group_tagged(pci_tsm_link_ops, link_ops,
+		struct pci_tsm *(*probe)(struct tsm_dev *tsm_dev,
+					 struct pci_dev *pdev);
+		void (*remove)(struct pci_tsm *tsm);
+		int (*connect)(struct pci_dev *pdev);
+		void (*disconnect)(struct pci_dev *pdev);
+		struct pci_tdi *(*bind)(struct pci_dev *pdev,
+					struct kvm *kvm, u32 tdi_id);
+		void (*unbind)(struct pci_tdi *tdi);
+		ssize_t (*guest_req)(struct pci_tdi *tdi,
+				     enum pci_tsm_req_scope scope,
+				     sockptr_t req_in, size_t in_len,
+				     sockptr_t req_out, size_t out_len,
+				     u64 *tsm_code);
+	);
+
+	/*
+	 * struct pci_tsm_devsec_ops - Manage the security state of the function
+	 * @lock: establish context with the TSM (allocate / wrap 'struct
+	 *	  pci_tsm') for follow-on security state transitions from the
+	 *	  LOCKED state
+	 * @unlock: destroy TSM context and return device to UNLOCKED state
+	 *
+	 * Context: @lock and @unlock run under pci_tsm_rwsem held for write to
+	 * sync with TSM unregistration and each other
+	 */
+	struct_group_tagged(pci_tsm_devsec_ops, devsec_ops,
+		struct pci_tsm *(*lock)(struct tsm_dev *tsm_dev,
+					struct pci_dev *pdev);
+		void (*unlock)(struct pci_tsm *tsm);
+	);
+};
+
+/**
+ * struct pci_tdi - Core TEE I/O Device Interface (TDI) context
+ * @pdev: host side representation of guest-side TDI
+ * @kvm: TEE VM context of bound TDI
+ * @tdi_id: Identifier (virtual BDF) for the TDI as referenced by the TSM and DSM
+ */
+struct pci_tdi {
+	struct pci_dev *pdev;
+	struct kvm *kvm;
+	u32 tdi_id;
+};
+
+/**
+ * struct pci_tsm - Core TSM context for a given PCIe endpoint
+ * @pdev: Back ref to device function, distinguishes type of pci_tsm context
+ * @dsm_dev: PCI Device Security Manager for link operations on @pdev
+ * @tsm_dev: PCI TEE Security Manager device for Link Confidentiality or Device
+ *	     Function Security operations
+ * @tdi: TDI context established by the @bind link operation
+ *
+ * This structure is wrapped by low level TSM driver data and returned by
+ * probe()/lock(), it is freed by the corresponding remove()/unlock().
+ *
+ * For link operations it serves to cache the association between a Device
+ * Security Manager (DSM) and the functions that manager can assign to a TVM.
+ * That can be "self", for assigning function0 of a TEE I/O device, a
+ * sub-function (SR-IOV virtual function, or non-function0
+ * multifunction-device), or a downstream endpoint (PCIe upstream switch-port as
+ * DSM).
+ */
+struct pci_tsm {
+	struct pci_dev *pdev;
+	struct pci_dev *dsm_dev;
+	struct tsm_dev *tsm_dev;
+	struct pci_tdi *tdi;
+};
+
+/**
+ * struct pci_tsm_pf0 - Physical Function 0 TDISP link context
+ * @base_tsm: generic core "tsm" context
+ * @lock: mutual exclustion for pci_tsm_ops invocation
+ * @doe_mb: PCIe Data Object Exchange mailbox
+ */
+struct pci_tsm_pf0 {
+	struct pci_tsm base_tsm;
+	struct mutex lock;
+	struct pci_doe_mb *doe_mb;
+};
+
+/* physical function0 and capable of 'connect' */
+static inline bool is_pci_tsm_pf0(struct pci_dev *pdev)
+{
+	if (!pdev)
+		return false;
+
+	if (!pci_is_pcie(pdev))
+		return false;
+
+	if (pdev->is_virtfn)
+		return false;
+
+	/*
+	 * Allow for a Device Security Manager (DSM) associated with function0
+	 * of an Endpoint to coordinate TDISP requests for other functions
+	 * (physical or virtual) of the device, or allow for an Upstream Port
+	 * DSM to accept TDISP requests for the Endpoints downstream of the
+	 * switch.
+	 */
+	switch (pci_pcie_type(pdev)) {
+	case PCI_EXP_TYPE_ENDPOINT:
+	case PCI_EXP_TYPE_UPSTREAM:
+	case PCI_EXP_TYPE_RC_END:
+		if (pdev->ide_cap || (pdev->devcap & PCI_EXP_DEVCAP_TEE))
+			break;
+		fallthrough;
+	default:
+		return false;
+	}
+
+	return PCI_FUNC(pdev->devfn) == 0;
+}
+
+/**
+ * enum pci_tsm_req_scope - Scope of guest requests to be validated by TSM
+ *
+ * Guest requests are a transport for a TVM to communicate with a TSM + DSM for
+ * a given TDI. A TSM driver is responsible for maintaining the kernel security
+ * model and limit commands that may affect the host, or are otherwise outside
+ * the typical TDISP operational model.
+ */
+enum pci_tsm_req_scope {
+	/**
+	 * @PCI_TSM_REQ_INFO: Read-only, without side effects, request for
+	 * typical TDISP collateral information like Device Interface Reports.
+	 * No device secrets are permitted, and no device state is changed.
+	 */
+	PCI_TSM_REQ_INFO = 0,
+	/**
+	 * @PCI_TSM_REQ_STATE_CHANGE: Request to change the TDISP state from
+	 * UNLOCKED->LOCKED, LOCKED->RUN, or other architecture specific state
+	 * changes to support those transitions for a TDI. No other (unrelated
+	 * to TDISP) device / host state, configuration, or data change is
+	 * permitted.
+	 */
+	PCI_TSM_REQ_STATE_CHANGE = 1,
+	/**
+	 * @PCI_TSM_REQ_DEBUG_READ: Read-only request for debug information
+	 *
+	 * A method to facilitate TVM information retrieval outside of typical
+	 * TDISP operational requirements. No device secrets are permitted.
+	 */
+	PCI_TSM_REQ_DEBUG_READ = 2,
+	/**
+	 * @PCI_TSM_REQ_DEBUG_WRITE: Device state changes for debug purposes
+	 *
+	 * The request may affect the operational state of the device outside of
+	 * the TDISP operational model. If allowed, requires CAP_SYS_RAW_IO, and
+	 * will taint the kernel.
+	 */
+	PCI_TSM_REQ_DEBUG_WRITE = 3,
+};
+
+#ifdef CONFIG_PCI_TSM
+int pci_tsm_register(struct tsm_dev *tsm_dev);
+void pci_tsm_unregister(struct tsm_dev *tsm_dev);
+int pci_tsm_link_constructor(struct pci_dev *pdev, struct pci_tsm *tsm,
+			     struct tsm_dev *tsm_dev);
+int pci_tsm_pf0_constructor(struct pci_dev *pdev, struct pci_tsm_pf0 *tsm,
+			    struct tsm_dev *tsm_dev);
+void pci_tsm_pf0_destructor(struct pci_tsm_pf0 *tsm);
+int pci_tsm_doe_transfer(struct pci_dev *pdev, u8 type, const void *req,
+			 size_t req_sz, void *resp, size_t resp_sz);
+int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u32 tdi_id);
+void pci_tsm_unbind(struct pci_dev *pdev);
+void pci_tsm_tdi_constructor(struct pci_dev *pdev, struct pci_tdi *tdi,
+			     struct kvm *kvm, u32 tdi_id);
+ssize_t pci_tsm_guest_req(struct pci_dev *pdev, enum pci_tsm_req_scope scope,
+			  sockptr_t req_in, size_t in_len, sockptr_t req_out,
+			  size_t out_len, u64 *tsm_code);
+#else
+static inline int pci_tsm_register(struct tsm_dev *tsm_dev)
+{
+	return 0;
+}
+static inline void pci_tsm_unregister(struct tsm_dev *tsm_dev)
+{
+}
+static inline int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u64 tdi_id)
+{
+	return -ENXIO;
+}
+static inline void pci_tsm_unbind(struct pci_dev *pdev)
+{
+}
+static inline ssize_t pci_tsm_guest_req(struct pci_dev *pdev,
+					enum pci_tsm_req_scope scope,
+					sockptr_t req_in, size_t in_len,
+					sockptr_t req_out, size_t out_len,
+					u64 *tsm_code)
+{
+	return -ENXIO;
+}
+#endif
+#endif /*__PCI_TSM_H */