[RFC 04/13] vfio: VFIO_IOMMU_BIND_GUEST_STAGE

[Eric Auger <eric.auger-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

From: "Liu, Yi L" <yi.l.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

This patch adds VFIO_IOMMU_BIND_GUEST_STAGE ioctl which aims at
passing the virtual iommu guest configuration to the VFIO driver
downto to the iommu subsystem.

Signed-off-by: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Liu, Yi L <yi.l.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Eric Auger <eric.auger-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

---

for SMMUV3 S1 config data passing the device parameter is not needed.
---
 drivers/vfio/vfio_iommu_type1.c | 56 +++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/vfio.h       |  8 ++++++
 2 files changed, 64 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index d9fd318..83c7f96 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1673,6 +1673,48 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
 	return ret;
 }
 
+struct vfio_iommu_task {
+	struct iommu_domain *domain;
+	void *payload;
+};
+
+static int bind_guest_stage_fn(struct device *dev, void *data)
+{
+	struct vfio_iommu_type1_bind_guest_stage *ustruct;
+	struct vfio_iommu_task *task = data;
+
+	ustruct = task->payload;
+	return iommu_bind_guest_stage(task->domain, dev, &ustruct->config);
+}
+
+static int vfio_iommu_dispatch_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_iommu_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)
 {
@@ -1743,6 +1785,20 @@ 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_BIND_GUEST_STAGE) {
+		struct vfio_iommu_type1_bind_guest_stage ustruct;
+
+		minsz = offsetofend(struct vfio_iommu_type1_bind_guest_stage,
+				    config);
+
+		if (copy_from_user(&ustruct, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (ustruct.argsz < minsz || ustruct.flags)
+			return -EINVAL;
+
+		return vfio_iommu_dispatch_task(iommu, (u8 *)&ustruct,
+						bind_guest_stage_fn);
 	}
 
 	return -ENOTTY;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 1aa7b82..a5801ed 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -14,6 +14,7 @@
 
 #include <linux/types.h>
 #include <linux/ioctl.h>
+#include <linux/iommu.h>
 
 #define VFIO_API_VERSION	0
 
@@ -665,6 +666,13 @@ struct vfio_iommu_type1_dma_unmap {
 #define VFIO_IOMMU_ENABLE	_IO(VFIO_TYPE, VFIO_BASE + 15)
 #define VFIO_IOMMU_DISABLE	_IO(VFIO_TYPE, VFIO_BASE + 16)
 
+struct vfio_iommu_type1_bind_guest_stage {
+	__u32	argsz;
+	__u32	flags;
+	struct iommu_guest_stage_config config;
+};
+#define VFIO_IOMMU_BIND_GUEST_STAGE	_IO(VFIO_TYPE, VFIO_BASE + 22)
+
 /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
 
 /*
-- 
2.5.5