diff mbox series

[v4,10/19] vfio: Add infrastructure for bind_iommufd from userspace

Message ID 20230221034812.138051-11-yi.l.liu@intel.com (mailing list archive)
State New, archived
Headers show
Series Add vfio_device cdev for iommufd support | expand

Commit Message

Yi Liu Feb. 21, 2023, 3:48 a.m. UTC 
For the device fd opened from cdev, userspace needs to bind it to an
iommufd and attach it to IOAS managed by iommufd. With such operations,
userspace can set up a secure DMA context and hence access device.

This changes the existing vfio_iommufd_bind() to accept a pt_id pointer
as an optional input, and also an dev_id pointer to selectively return
the dev_id to prepare for adding bind_iommufd ioctl, which does the bind
first and then attach IOAS.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
 drivers/vfio/group.c     | 17 ++++++++++++++---
 drivers/vfio/iommufd.c   | 21 +++++++++------------
 drivers/vfio/vfio.h      |  9 ++++++---
 drivers/vfio/vfio_main.c | 10 ++++++----
 4 files changed, 35 insertions(+), 22 deletions(-)
diff mbox series

Patch

diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 14e29525e354..77559e035078 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -169,6 +169,7 @@  static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
 static int vfio_device_group_open(struct vfio_device_file *df)
 {
 	struct vfio_device *device = df->device;
+	u32 ioas_id;
 	int ret;
 
 	mutex_lock(&device->group->group_lock);
@@ -177,6 +178,13 @@  static int vfio_device_group_open(struct vfio_device_file *df)
 		goto out_unlock;
 	}
 
+	if (device->group->iommufd) {
+		ret = iommufd_vfio_compat_ioas_id(device->group->iommufd,
+						  &ioas_id);
+		if (ret)
+			goto out_unlock;
+	}
+
 	mutex_lock(&device->dev_set->lock);
 
 	/*
@@ -188,9 +196,12 @@  static int vfio_device_group_open(struct vfio_device_file *df)
 	if (device->open_count == 0)
 		vfio_device_group_get_kvm_safe(device);
 
-	df->iommufd = device->group->iommufd;
-
-	ret = vfio_device_open(df);
+	if (device->group->iommufd) {
+		df->iommufd = device->group->iommufd;
+		ret = vfio_device_open(df, NULL, &ioas_id);
+	} else {
+		ret = vfio_device_open(df, NULL, NULL);
+	}
 	if (ret)
 		df->iommufd = NULL;
 
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 4f82a6fa7c6c..beef6ca21107 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -10,9 +10,9 @@ 
 MODULE_IMPORT_NS(IOMMUFD);
 MODULE_IMPORT_NS(IOMMUFD_VFIO);
 
-int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
+int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx,
+		      u32 *dev_id, u32 *pt_id)
 {
-	u32 ioas_id;
 	u32 device_id;
 	int ret;
 
@@ -29,17 +29,14 @@  int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
 	if (ret)
 		return ret;
 
-	ret = iommufd_vfio_compat_ioas_id(ictx, &ioas_id);
-	if (ret)
-		goto err_unbind;
-	ret = vdev->ops->attach_ioas(vdev, &ioas_id);
-	if (ret)
-		goto err_unbind;
+	if (pt_id) {
+		ret = vdev->ops->attach_ioas(vdev, pt_id);
+		if (ret)
+			goto err_unbind;
+	}
 
-	/*
-	 * The legacy path has no way to return the device id or the selected
-	 * pt_id
-	 */
+	if (dev_id)
+		*dev_id = device_id;
 	return 0;
 
 err_unbind:
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index d56cdb114024..6f063e31d08a 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -26,7 +26,8 @@  struct vfio_device_file {
 
 void vfio_device_put_registration(struct vfio_device *device);
 bool vfio_device_try_get_registration(struct vfio_device *device);
-int vfio_device_open(struct vfio_device_file *df);
+int vfio_device_open(struct vfio_device_file *df,
+		     u32 *dev_id, u32 *pt_id);
 void vfio_device_close(struct vfio_device_file *df);
 struct vfio_device_file *
 vfio_allocate_device_file(struct vfio_device *device);
@@ -224,11 +225,13 @@  static inline void vfio_container_cleanup(void)
 #endif
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
-int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
+int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx,
+		      u32 *dev_id, u32 *pt_id);
 void vfio_iommufd_unbind(struct vfio_device *device);
 #else
 static inline int vfio_iommufd_bind(struct vfio_device *device,
-				    struct iommufd_ctx *ictx)
+				    struct iommufd_ctx *ictx,
+				    u32 *dev_id, u32 *pt_id)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 2c851e172586..fd5b4dfa9615 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -411,7 +411,8 @@  vfio_allocate_device_file(struct vfio_device *device)
 	return df;
 }
 
-static int vfio_device_first_open(struct vfio_device_file *df)
+static int vfio_device_first_open(struct vfio_device_file *df,
+				  u32 *dev_id, u32 *pt_id)
 {
 	struct vfio_device *device = df->device;
 	struct iommufd_ctx *iommufd = df->iommufd;
@@ -423,7 +424,7 @@  static int vfio_device_first_open(struct vfio_device_file *df)
 		return -ENODEV;
 
 	if (iommufd)
-		ret = vfio_iommufd_bind(device, iommufd);
+		ret = vfio_iommufd_bind(device, iommufd, dev_id, pt_id);
 	else
 		ret = vfio_device_group_use_iommu(device);
 	if (ret)
@@ -462,7 +463,8 @@  static void vfio_device_last_close(struct vfio_device_file *df)
 	module_put(device->dev->driver->owner);
 }
 
-int vfio_device_open(struct vfio_device_file *df)
+int vfio_device_open(struct vfio_device_file *df,
+		     u32 *dev_id, u32 *pt_id)
 {
 	struct vfio_device *device = df->device;
 	int ret = 0;
@@ -471,7 +473,7 @@  int vfio_device_open(struct vfio_device_file *df)
 
 	device->open_count++;
 	if (device->open_count == 1) {
-		ret = vfio_device_first_open(df);
+		ret = vfio_device_first_open(df, dev_id, pt_id);
 		if (ret)
 			device->open_count--;
 	}