[RFC PATCH v4 12/16] coco: host: arm64: Fetch device measurements via RMI

["Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>]

- define __RHI_DA_VDEV_GET_MEASUREMENTS for guest requests and
  expose the RMI SMC ID/wrapper for RMI_VDEV_GET_DEV_MEASUREMENTS
- teach the CCA host driver to handle the new guest request by fetching
  the device measurements from RMM using rmi_vdev_get_device_measurements()
  and refreshing the cached buffer
- add a helper that submits a DOE work to pull the latest device
  measurements into the cache

This lets guests request up-to-date device measurements via RHI

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 arch/arm64/include/asm/rmi_cmds.h        | 12 +++++
 arch/arm64/include/asm/rmi_smc.h         | 13 +++++
 arch/arm64/include/uapi/asm/rmi-da.h     |  8 +++
 drivers/virt/coco/arm-cca-host/arm-cca.c | 16 ++++++
 drivers/virt/coco/arm-cca-host/rmi-da.c  | 68 ++++++++++++++++++++++++
 drivers/virt/coco/arm-cca-host/rmi-da.h  |  1 +
 6 files changed, 118 insertions(+)

diff --git a/arch/arm64/include/asm/rmi_cmds.h b/arch/arm64/include/asm/rmi_cmds.h
index b3c04029bb47..350fd9bc93a4 100644
--- a/arch/arm64/include/asm/rmi_cmds.h
+++ b/arch/arm64/include/asm/rmi_cmds.h
@@ -981,4 +981,16 @@ static inline unsigned long rmi_vdev_get_interface_report(unsigned long rd,
 	return res.a0;
 }
 
+static inline unsigned long
+rmi_vdev_get_device_measurements(unsigned long rd, unsigned long pdev_phys,
+				 unsigned long vdev_phys,
+				 unsigned long param_phys)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_VDEV_GET_MEASUREMENTS,
+			     rd, pdev_phys, vdev_phys, param_phys, &res);
+
+	return res.a0;
+}
 #endif /* __ASM_RMI_CMDS_H */
diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h
index 6cd5439f56ec..29dbe4e0dfb0 100644
--- a/arch/arm64/include/asm/rmi_smc.h
+++ b/arch/arm64/include/asm/rmi_smc.h
@@ -674,4 +674,17 @@ struct rmi_vdev_params {
 	};
 };
 
+#define RMI_VDEV_MEASURE_HASH	0x0
+#define RMI_VDEV_MEASURE_RAW	0x1
+struct rmi_vdev_measurement_params {
+	union {
+		u64 flags;
+		u8 padding0[256];
+	};
+	union {
+		u8 nonce[32];
+		u8 padding1[256];
+	};
+};
+
 #endif /* __ASM_RMI_SMC_H */
diff --git a/arch/arm64/include/uapi/asm/rmi-da.h b/arch/arm64/include/uapi/asm/rmi-da.h
index 8d36a4c59849..97648928f763 100644
--- a/arch/arm64/include/uapi/asm/rmi-da.h
+++ b/arch/arm64/include/uapi/asm/rmi-da.h
@@ -21,4 +21,12 @@ struct arm64_vdev_object_read_guest_req {
 /* No arguments to this guest request */
 #define __RHI_DA_VDEV_UPDATE_INTERFACE_REPORT 0x3
 
+struct arm64_vdev_device_measurement_guest_req {
+	__u32 req_type;
+	__u32 reserved;
+	__aligned_u64 flags;
+	__aligned_u64 nonce;
+};
+#define __RHI_DA_VDEV_UPDATE_MEASUREMENTS	0x4
+
 #endif
diff --git a/drivers/virt/coco/arm-cca-host/arm-cca.c b/drivers/virt/coco/arm-cca-host/arm-cca.c
index 2955993d29ac..855427935f2d 100644
--- a/drivers/virt/coco/arm-cca-host/arm-cca.c
+++ b/drivers/virt/coco/arm-cca-host/arm-cca.c
@@ -565,6 +565,22 @@ static ssize_t cca_tsm_guest_req(struct pci_tdi *tdi, enum pci_tsm_req_scope sco
 		{
 			return cca_vdev_update_interface_report(pdev);
 		}
+		case __RHI_DA_VDEV_UPDATE_MEASUREMENTS:
+		{
+			int ret;
+			struct arm64_vdev_device_measurement_guest_req req_obj;
+
+			if (req_len != sizeof(req_obj))
+				return -EINVAL;
+
+			if (copy_from_user((void *)&req_obj, req.user, req_len))
+				return -EFAULT;
+
+			ret = cca_vdev_update_device_measurements(pdev,
+								  req_obj.flags,
+								  (u8 *)req_obj.nonce);
+			return ret;
+		}
 		default:
 			return -EINVAL;
 		}
diff --git a/drivers/virt/coco/arm-cca-host/rmi-da.c b/drivers/virt/coco/arm-cca-host/rmi-da.c
index 1862e4ff8cbb..ec7701ff7e03 100644
--- a/drivers/virt/coco/arm-cca-host/rmi-da.c
+++ b/drivers/virt/coco/arm-cca-host/rmi-da.c
@@ -1309,3 +1309,71 @@ int cca_vdev_update_interface_report(struct pci_dev *pdev)
 	/* get and update the interface report cache. */
 	return vdev_update_interface_report_cache(pdev);
 }
+
+static int vdev_update_device_measurements_cache(struct pci_dev *pdev)
+{
+	struct dev_comm_work comm_work;
+	struct cca_host_tdi *host_tdi = to_cca_host_tdi(pdev);
+	struct cca_host_comm_data *comm_data = to_cca_comm_data(pdev);
+
+	INIT_WORK_ONSTACK(&comm_work.work, vdev_fetch_object_workfn);
+	comm_work.tsm = pdev->tsm;
+	if (host_tdi->measurements) {
+		comm_work.cache_buf = host_tdi->measurements->buf;
+		comm_work.cache_offset = &host_tdi->measurements->offset;
+		comm_work.cache_size = host_tdi->measurements->size;
+	} else {
+		comm_work.cache_buf = NULL;
+		comm_work.cache_offset = NULL;
+		comm_work.cache_size = 0;
+	}
+
+	queue_work(comm_data->work_queue, &comm_work.work);
+	flush_work(&comm_work.work);
+	destroy_work_on_stack(&comm_work.work);
+
+	if (comm_work.cache_size == 0)
+		return -ENXIO;
+	return 0;
+}
+
+static inline void vdev_measurement_param_free(struct rmi_vdev_measurement_params *param)
+{
+	return free_page((unsigned long)param);
+}
+DEFINE_FREE(measurement_param_free, struct rmi_vdev_measurement_params *, if (_T) vdev_measurement_param_free(_T))
+
+int cca_vdev_update_device_measurements(struct pci_dev *pdev, unsigned long flags, u8 *nonce)
+{
+	struct realm *realm;
+	phys_addr_t rd_phys;
+	phys_addr_t rmm_pdev_phys;
+	phys_addr_t rmm_vdev_phys;
+	struct cca_host_tdi *host_tdi;
+	struct cca_host_pdev_dsc *pdev_dsc;
+
+	host_tdi = to_cca_host_tdi(pdev);
+	rmm_vdev_phys = virt_to_phys(host_tdi->rmm_vdev);
+	realm = &host_tdi->tdi.kvm->arch.realm;
+	rd_phys = virt_to_phys(realm->rd);
+
+	pdev_dsc = to_cca_pdev_dsc(pdev->tsm->dsm_dev);
+	rmm_pdev_phys = virt_to_phys(pdev_dsc->rmm_pdev);
+
+	struct rmi_vdev_measurement_params *params __free(measurement_param_free) =
+		(struct rmi_vdev_measurement_params *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	if (!params)
+		return -ENOMEM;
+
+	params->flags = flags;
+
+	if (copy_from_user(params->nonce, nonce, sizeof(params->nonce)))
+		return -EFAULT;
+
+	if (rmi_vdev_get_device_measurements(rd_phys, rmm_pdev_phys,
+					     rmm_vdev_phys, virt_to_phys(params)))
+		return -ENXIO;
+
+	/* get and update the interface report cache. */
+	return vdev_update_device_measurements_cache(pdev);
+}
diff --git a/drivers/virt/coco/arm-cca-host/rmi-da.h b/drivers/virt/coco/arm-cca-host/rmi-da.h
index b114bf4d4202..621e0858f0c6 100644
--- a/drivers/virt/coco/arm-cca-host/rmi-da.h
+++ b/drivers/virt/coco/arm-cca-host/rmi-da.h
@@ -249,5 +249,6 @@ int cca_vdev_get_object_size(struct pci_dev *pdev, int type);
 int cca_vdev_read_cached_object(struct pci_dev *pdev, int type, unsigned long offset,
 		unsigned long max_len, void __user *user_buf);
 int cca_vdev_update_interface_report(struct pci_dev *pdev);
+int cca_vdev_update_device_measurements(struct pci_dev *pdev, unsigned long flags, u8 *nonce);
 
 #endif
-- 
2.43.0