[RFC PATCH 6/8] VFIO: do pasid table binding

["Liu, Yi L" <yi.l.liu@xxxxxxxxx>]

From: "Liu, Yi L" <yi.l.liu@xxxxxxxxxxxxxxx>

This patch adds IOCTL processing in vfio_iommu_type1 for
VFIO_IOMMU_SVM_BIND_TASK. Binds the PASID table bind by
calling iommu_ops->bind_pasid_table to link the whole
PASID table to pIOMMU.

For VT-d, it is linking the guest PASID table to host pIOMMU.
This is key point to support SVM virtualization on VT-d.

Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx>
---
 drivers/vfio/vfio_iommu_type1.c | 72 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index b3cc33f..30b6d48 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1512,6 +1512,50 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
 	return ret;
 }
 
+struct vfio_svm_task {
+	struct iommu_domain *domain;
+	void *payload;
+};
+
+static int bind_pasid_tbl_fn(struct device *dev, void *data)
+{
+	int ret = 0;
+	struct vfio_svm_task *task = data;
+	struct pasid_table_info *pasidt_binfo;
+
+	pasidt_binfo = task->payload;
+	ret = iommu_bind_pasid_table(task->domain, dev, pasidt_binfo);
+	return ret;
+}
+
+static int vfio_do_svm_task(struct vfio_iommu *iommu, void *data,
+				int (*fn)(struct device *, void *))
+{
+	int ret = 0;
+	struct vfio_domain *d;
+	struct vfio_group *g;
+	struct vfio_svm_task task;
+
+	task.payload = data;
+
+	mutex_lock(&iommu->lock);
+
+	list_for_each_entry(d, &iommu->domain_list, next) {
+		list_for_each_entry(g, &d->group_list, next) {
+			if (g->iommu_group != NULL) {
+				task.domain = d->domain;
+				ret = iommu_group_for_each_dev(
+					g->iommu_group, &task, fn);
+				if (ret != 0)
+					break;
+			}
+		}
+	}
+
+	mutex_unlock(&iommu->lock);
+	return ret;
+}
+
 static long vfio_iommu_type1_ioctl(void *iommu_data,
 				   unsigned int cmd, unsigned long arg)
 {
@@ -1582,6 +1626,34 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 		return copy_to_user((void __user *)arg, &unmap, minsz) ?
 			-EFAULT : 0;
+	} else if (cmd == VFIO_IOMMU_SVM_BIND_TASK) {
+		struct vfio_device_svm hdr;
+		u8 *data = NULL;
+		int ret = 0;
+
+		minsz = offsetofend(struct vfio_device_svm, length);
+		if (copy_from_user(&hdr, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (hdr.length == 0)
+			return -EINVAL;
+
+		data = memdup_user((void __user *)(arg + minsz),
+					hdr.length);
+		if (IS_ERR(data))
+			return PTR_ERR(data);
+
+		switch (hdr.flags & VFIO_SVM_TYPE_MASK) {
+		case VFIO_SVM_BIND_PASIDTBL:
+			ret = vfio_do_svm_task(iommu, data,
+						bind_pasid_tbl_fn);
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		kfree(data);
+		return ret;
 	}
 
 	return -ENOTTY;
-- 
1.9.1