[RFC PATCH v4 15/16] coco: host: arm64: Transition vdevs to TDISP RUN state

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

Add host-side support for guest requests that move a vdev into the TDISP
RUN state.

Introduce the RMI helper for VDEV_START and a matching guest request
payload for VDEV_SET_TDI_STATE. In the host CCA TSM request handler, accept
only RHI_DA_TDI_CONFIG_RUN on the state-change path and invoke a new
cca_vdev_device_start() helper.

The start helper issues RMI_VDEV_START for the bound pdev/vdev pair and
then waits until firmware reports the vdev in the RMI_VDEV_STARTED state
before returning to the caller.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 arch/arm64/include/asm/rmi_cmds.h        | 11 +++++++++++
 arch/arm64/include/uapi/asm/rmi-da.h     |  6 ++++++
 drivers/virt/coco/arm-cca-host/arm-cca.c | 15 +++++++++++++++
 drivers/virt/coco/arm-cca-host/rmi-da.c  | 22 ++++++++++++++++++++++
 drivers/virt/coco/arm-cca-host/rmi-da.h  |  1 +
 5 files changed, 55 insertions(+)

diff --git a/arch/arm64/include/asm/rmi_cmds.h b/arch/arm64/include/asm/rmi_cmds.h
index 350fd9bc93a4..19eba97a6c7b 100644
--- a/arch/arm64/include/asm/rmi_cmds.h
+++ b/arch/arm64/include/asm/rmi_cmds.h
@@ -993,4 +993,15 @@ rmi_vdev_get_device_measurements(unsigned long rd, unsigned long pdev_phys,
 
 	return res.a0;
 }
+
+static inline unsigned long rmi_vdev_start(unsigned long rd, unsigned long pdev_phys,
+					   unsigned long vdev_phys)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_VDEV_START, rd, pdev_phys, vdev_phys, &res);
+
+	return res.a0;
+}
+
 #endif /* __ASM_RMI_CMDS_H */
diff --git a/arch/arm64/include/uapi/asm/rmi-da.h b/arch/arm64/include/uapi/asm/rmi-da.h
index 572afb4095f2..c0cfcadfae47 100644
--- a/arch/arm64/include/uapi/asm/rmi-da.h
+++ b/arch/arm64/include/uapi/asm/rmi-da.h
@@ -38,4 +38,10 @@ struct arm64_vdev_device_memmap_guest_req {
 };
 #define __REC_DA_VDEV_MAP		0x5
 
+struct arm64_vdev_set_tdi_state_guest_req {
+	__u32 req_type;
+	__u32 tdi_state;
+};
+#define __RHI_DA_VDEV_SET_TDI_STATE	0x6
+
 #endif
diff --git a/drivers/virt/coco/arm-cca-host/arm-cca.c b/drivers/virt/coco/arm-cca-host/arm-cca.c
index 66e0acadf743..3a682352fb68 100644
--- a/drivers/virt/coco/arm-cca-host/arm-cca.c
+++ b/drivers/virt/coco/arm-cca-host/arm-cca.c
@@ -608,6 +608,21 @@ static ssize_t cca_tsm_guest_req(struct pci_tdi *tdi, enum pci_tsm_req_scope sco
 						   req_obj.gpa_top,
 						   req_obj.pa_base);
 		}
+		case __RHI_DA_VDEV_SET_TDI_STATE:
+		{
+			struct arm64_vdev_set_tdi_state_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;
+
+			if (req_obj.tdi_state != RHI_DA_TDI_CONFIG_RUN)
+				return -EINVAL;
+
+			return cca_vdev_device_start(pdev);
+		}
 		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 543c40fb1160..60b750c961ea 100644
--- a/drivers/virt/coco/arm-cca-host/rmi-da.c
+++ b/drivers/virt/coco/arm-cca-host/rmi-da.c
@@ -1398,3 +1398,25 @@ int cca_vdev_device_map(struct pci_dev *pdev, unsigned long gpa_base,
 	return realm_dev_mem_map(kvm, rmm_pdev_phys, rmm_vdev_phys,
 				 gpa_base, gpa_top, pa_base);
 }
+
+int cca_vdev_device_start(struct pci_dev *pdev)
+{
+	phys_addr_t rmm_pdev_phys;
+	phys_addr_t rmm_vdev_phys;
+	struct cca_host_pdev_dsc *pdev_dsc;
+	struct cca_host_tdi *host_tdi;
+	struct realm *realm;
+	phys_addr_t rd_phys;
+
+	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);
+
+	if (rmi_vdev_start(rd_phys, rmm_pdev_phys, rmm_vdev_phys))
+		return -ENXIO;
+	return submit_vdev_state_transition_work(pdev, RMI_VDEV_STARTED);
+}
diff --git a/drivers/virt/coco/arm-cca-host/rmi-da.h b/drivers/virt/coco/arm-cca-host/rmi-da.h
index 3dfb6b3cc2ef..3082166038c3 100644
--- a/drivers/virt/coco/arm-cca-host/rmi-da.h
+++ b/drivers/virt/coco/arm-cca-host/rmi-da.h
@@ -252,5 +252,6 @@ 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);
 int cca_vdev_device_map(struct pci_dev *pdev, unsigned long gpa_base,
 		unsigned long gpa_top, unsigned long pa_base);
+int cca_vdev_device_start(struct pci_dev *pdev);
 
 #endif
-- 
2.43.0