[PATCH v1 09/16] iommufd/viommmu: Add IOMMUFD_CMD_VCMDQ_ALLOC ioctl

[Nicolin Chen <nicolinc@nvidia.com>]

Introduce a new IOMMUFD_CMD_VCMDQ_ALLOC ioctl for user space to allocate
a vCMDQ for a vIOMMU object. Simply increase the refcount of the vIOMMU.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/iommufd/iommufd_private.h |  2 +
 include/uapi/linux/iommufd.h            | 32 +++++++++++++
 drivers/iommu/iommufd/main.c            |  6 +++
 drivers/iommu/iommufd/viommu.c          | 61 +++++++++++++++++++++++++
 4 files changed, 101 insertions(+)

diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 8d96aa514033..da35ffcc212b 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -605,6 +605,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd);
 void iommufd_viommu_destroy(struct iommufd_object *obj);
 int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd);
 void iommufd_vdevice_destroy(struct iommufd_object *obj);
+int iommufd_vcmdq_alloc_ioctl(struct iommufd_ucmd *ucmd);
+void iommufd_vcmdq_destroy(struct iommufd_object *obj);
 
 #ifdef CONFIG_IOMMUFD_TEST
 int iommufd_test(struct iommufd_ucmd *ucmd);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index cc90299a08d9..428f1e9e6239 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -56,6 +56,7 @@ enum {
 	IOMMUFD_CMD_VDEVICE_ALLOC = 0x91,
 	IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92,
 	IOMMUFD_CMD_VEVENTQ_ALLOC = 0x93,
+	IOMMUFD_CMD_VCMDQ_ALLOC = 0x94,
 };
 
 /**
@@ -1147,4 +1148,35 @@ struct iommu_veventq_alloc {
 	__u32 __reserved;
 };
 #define IOMMU_VEVENTQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VEVENTQ_ALLOC)
+
+/**
+ * enum iommu_vcmdq_type - Virtual Queue Type
+ * @IOMMU_VCMDQ_TYPE_DEFAULT: Reserved for future use
+ */
+enum iommu_vcmdq_data_type {
+	IOMMU_VCMDQ_TYPE_DEFAULT = 0,
+};
+
+/**
+ * struct iommu_vcmdq_alloc - ioctl(IOMMU_VCMDQ_ALLOC)
+ * @size: sizeof(struct iommu_vcmdq_alloc)
+ * @flags: Must be 0
+ * @viommu_id: viommu ID to associate the virtual queue with
+ * @type: One of enum iommu_vcmdq_type
+ * @out_vcmdq_id: The ID of the new virtual queue
+ * @data_len: Length of the type specific data
+ * @data_uptr: User pointer to the type specific data
+ *
+ * Allocate a virtual queue object for vIOMMU-specific HW-accelerated queue
+ */
+struct iommu_vcmdq_alloc {
+	__u32 size;
+	__u32 flags;
+	__u32 viommu_id;
+	__u32 type;
+	__u32 out_vcmdq_id;
+	__u32 data_len;
+	__aligned_u64 data_uptr;
+};
+#define IOMMU_VCMDQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VCMDQ_ALLOC)
 #endif
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 2b9ee9b4a424..27473aff150f 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -303,6 +303,7 @@ union ucmd_buffer {
 	struct iommu_ioas_map map;
 	struct iommu_ioas_unmap unmap;
 	struct iommu_option option;
+	struct iommu_vcmdq_alloc vcmdq;
 	struct iommu_vdevice_alloc vdev;
 	struct iommu_veventq_alloc veventq;
 	struct iommu_vfio_ioas vfio_ioas;
@@ -358,6 +359,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
 	IOCTL_OP(IOMMU_IOAS_UNMAP, iommufd_ioas_unmap, struct iommu_ioas_unmap,
 		 length),
 	IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option, val64),
+	IOCTL_OP(IOMMU_VCMDQ_ALLOC, iommufd_vcmdq_alloc_ioctl,
+		 struct iommu_vcmdq_alloc, data_uptr),
 	IOCTL_OP(IOMMU_VDEVICE_ALLOC, iommufd_vdevice_alloc_ioctl,
 		 struct iommu_vdevice_alloc, virt_id),
 	IOCTL_OP(IOMMU_VEVENTQ_ALLOC, iommufd_veventq_alloc,
@@ -501,6 +504,9 @@ static const struct iommufd_object_ops iommufd_object_ops[] = {
 	[IOMMUFD_OBJ_IOAS] = {
 		.destroy = iommufd_ioas_destroy,
 	},
+	[IOMMUFD_OBJ_VCMDQ] = {
+		.destroy = iommufd_vcmdq_destroy,
+	},
 	[IOMMUFD_OBJ_VDEVICE] = {
 		.destroy = iommufd_vdevice_destroy,
 	},
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index a65153458a26..c5a0db132e03 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -170,3 +170,64 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
 	iommufd_put_object(ucmd->ictx, &viommu->obj);
 	return rc;
 }
+
+void iommufd_vcmdq_destroy(struct iommufd_object *obj)
+{
+	struct iommufd_vcmdq *vcmdq =
+		container_of(obj, struct iommufd_vcmdq, obj);
+	struct iommufd_viommu *viommu = vcmdq->viommu;
+
+	if (viommu->ops->vcmdq_free)
+		viommu->ops->vcmdq_free(vcmdq);
+	refcount_dec(&viommu->obj.users);
+}
+
+int iommufd_vcmdq_alloc_ioctl(struct iommufd_ucmd *ucmd)
+{
+	struct iommu_vcmdq_alloc *cmd = ucmd->cmd;
+	const struct iommu_user_data user_data = {
+		.type = cmd->type,
+		.uptr = u64_to_user_ptr(cmd->data_uptr),
+		.len = cmd->data_len,
+	};
+	struct iommufd_vcmdq *vcmdq;
+	struct iommufd_viommu *viommu;
+	int rc;
+
+	if (cmd->flags || cmd->type == IOMMU_VCMDQ_TYPE_DEFAULT)
+		return -EOPNOTSUPP;
+	if (!cmd->data_len)
+		return -EINVAL;
+
+	viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
+	if (IS_ERR(viommu))
+		return PTR_ERR(viommu);
+
+	if (!viommu->ops || !viommu->ops->vcmdq_alloc) {
+		rc = -EOPNOTSUPP;
+		goto out_put_viommu;
+	}
+
+	vcmdq = viommu->ops->vcmdq_alloc(viommu,
+					 user_data.len ? &user_data : NULL);
+	if (IS_ERR(vcmdq)) {
+		rc = PTR_ERR(vcmdq);
+		goto out_put_viommu;
+	}
+
+	vcmdq->viommu = viommu;
+	refcount_inc(&viommu->obj.users);
+	vcmdq->ictx = ucmd->ictx;
+	cmd->out_vcmdq_id = vcmdq->obj.id;
+	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
+	if (rc)
+		goto out_abort;
+	iommufd_object_finalize(ucmd->ictx, &vcmdq->obj);
+	goto out_put_viommu;
+
+out_abort:
+	iommufd_object_abort_and_destroy(ucmd->ictx, &vcmdq->obj);
+out_put_viommu:
+	iommufd_put_object(ucmd->ictx, &viommu->obj);
+	return rc;
+}
-- 
2.43.0