4 files changed, 206 insertions, 94 deletions

diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c
index 8772dad68085..7f3961fd4b5a 100644
--- a/drivers/vfio/container.c
+++ b/drivers/vfio/container.c
@@ -540,113 +540,41 @@ void vfio_group_unuse_container(struct vfio_group *group)
 	fput(group->opened_file);
 }
 
-/*
- * Pin contiguous user pages and return their associated host pages for local
- * domain only.
- * @device [in]  : device
- * @iova [in]    : starting IOVA of user pages to be pinned.
- * @npage [in]   : count of pages to be pinned.  This count should not
- *		   be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
- * @prot [in]    : protection flags
- * @pages[out]   : array of host pages
- * Return error or number of pages pinned.
- *
- * A driver may only call this function if the vfio_device was created
- * by vfio_register_emulated_iommu_dev().
- */
-int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
-		   int npage, int prot, struct page **pages)
+int vfio_container_pin_pages(struct vfio_container *container,
+			     struct iommu_group *iommu_group, dma_addr_t iova,
+			     int npage, int prot, struct page **pages)
 {
-	struct vfio_container *container;
-	struct vfio_group *group = device->group;
-	struct vfio_iommu_driver *driver;
-	int ret;
-
-	if (!pages || !npage || !vfio_assert_device_open(device))
-		return -EINVAL;
+	struct vfio_iommu_driver *driver = container->iommu_driver;
 
 	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
 		return -E2BIG;
 
-	/* group->container cannot change while a vfio device is open */
-	container = group->container;
-	driver = container->iommu_driver;
-	if (likely(driver && driver->ops->pin_pages))
-		ret = driver->ops->pin_pages(container->iommu_data,
-					     group->iommu_group, iova,
-					     npage, prot, pages);
-	else
-		ret = -ENOTTY;
-
-	return ret;
+	if (unlikely(!driver || !driver->ops->pin_pages))
+		return -ENOTTY;
+	return driver->ops->pin_pages(container->iommu_data, iommu_group, iova,
+				      npage, prot, pages);
 }
-EXPORT_SYMBOL(vfio_pin_pages);
 
-/*
- * Unpin contiguous host pages for local domain only.
- * @device [in]  : device
- * @iova [in]    : starting address of user pages to be unpinned.
- * @npage [in]   : count of pages to be unpinned.  This count should not
- *                 be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
- */
-void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
+void vfio_container_unpin_pages(struct vfio_container *container,
+				dma_addr_t iova, int npage)
 {
-	struct vfio_container *container;
-	struct vfio_iommu_driver *driver;
-
 	if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES))
 		return;
 
-	if (WARN_ON(!vfio_assert_device_open(device)))
-		return;
-
-	/* group->container cannot change while a vfio device is open */
-	container = device->group->container;
-	driver = container->iommu_driver;
-
-	driver->ops->unpin_pages(container->iommu_data, iova, npage);
+	container->iommu_driver->ops->unpin_pages(container->iommu_data, iova,
+						  npage);
 }
-EXPORT_SYMBOL(vfio_unpin_pages);
 
-/*
- * This interface allows the CPUs to perform some sort of virtual DMA on
- * behalf of the device.
- *
- * CPUs read/write from/into a range of IOVAs pointing to user space memory
- * into/from a kernel buffer.
- *
- * As the read/write of user space memory is conducted via the CPUs and is
- * not a real device DMA, it is not necessary to pin the user space memory.
- *
- * @device [in]		: VFIO device
- * @iova [in]		: base IOVA of a user space buffer
- * @data [in]		: pointer to kernel buffer
- * @len [in]		: kernel buffer length
- * @write		: indicate read or write
- * Return error code on failure or 0 on success.
- */
-int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
-		size_t len, bool write)
+int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
+			  void *data, size_t len, bool write)
 {
-	struct vfio_container *container;
-	struct vfio_iommu_driver *driver;
-	int ret = 0;
-
-	if (!data || len <= 0 || !vfio_assert_device_open(device))
-		return -EINVAL;
-
-	/* group->container cannot change while a vfio device is open */
-	container = device->group->container;
-	driver = container->iommu_driver;
+	struct vfio_iommu_driver *driver = container->iommu_driver;
 
-	if (likely(driver && driver->ops->dma_rw))
-		ret = driver->ops->dma_rw(container->iommu_data,
-					  iova, data, len, write);
-	else
-		ret = -ENOTTY;
-	return ret;
+	if (unlikely(!driver || !driver->ops->dma_rw))
+		return -ENOTTY;
+	return driver->ops->dma_rw(container->iommu_data, iova, data, len,
+				   write);
 }
-EXPORT_SYMBOL(vfio_dma_rw);
 
 int __init vfio_container_init(void)
 {
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 6e47a3df1a71..4f82a6fa7c6c 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -98,3 +98,61 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);
+
+/*
+ * The emulated standard ops mean that vfio_device is going to use the
+ * "mdev path" and will call vfio_pin_pages()/vfio_dma_rw(). Drivers using this
+ * ops set should call vfio_register_emulated_iommu_dev().
+ */
+
+static void vfio_emulated_unmap(void *data, unsigned long iova,
+				unsigned long length)
+{
+	struct vfio_device *vdev = data;
+
+	vdev->ops->dma_unmap(vdev, iova, length);
+}
+
+static const struct iommufd_access_ops vfio_user_ops = {
+	.needs_pin_pages = 1,
+	.unmap = vfio_emulated_unmap,
+};
+
+int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
+			       struct iommufd_ctx *ictx, u32 *out_device_id)
+{
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	vdev->iommufd_ictx = ictx;
+	iommufd_ctx_get(ictx);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_bind);
+
+void vfio_iommufd_emulated_unbind(struct vfio_device *vdev)
+{
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	if (vdev->iommufd_access) {
+		iommufd_access_destroy(vdev->iommufd_access);
+		vdev->iommufd_access = NULL;
+	}
+	iommufd_ctx_put(vdev->iommufd_ictx);
+	vdev->iommufd_ictx = NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_unbind);
+
+int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
+{
+	struct iommufd_access *user;
+
+	lockdep_assert_held(&vdev->dev_set->lock);
+
+	user = iommufd_access_create(vdev->iommufd_ictx, *pt_id, &vfio_user_ops,
+				     vdev);
+	if (IS_ERR(user))
+		return PTR_ERR(user);
+	vdev->iommufd_access = user;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas);
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 9766f70a12c5..b1ef84249637 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -111,8 +111,6 @@ struct vfio_iommu_driver {
 int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
 void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops);
 
-bool vfio_assert_device_open(struct vfio_device *device);
-
 struct vfio_container *vfio_container_from_file(struct file *filep);
 int vfio_group_use_container(struct vfio_group *group);
 void vfio_group_unuse_container(struct vfio_group *group);
@@ -121,6 +119,14 @@ int vfio_container_attach_group(struct vfio_container *container,
 void vfio_group_detach_container(struct vfio_group *group);
 void vfio_device_container_register(struct vfio_device *device);
 void vfio_device_container_unregister(struct vfio_device *device);
+int vfio_container_pin_pages(struct vfio_container *container,
+			     struct iommu_group *iommu_group, dma_addr_t iova,
+			     int npage, int prot, struct page **pages);
+void vfio_container_unpin_pages(struct vfio_container *container,
+				dma_addr_t iova, int npage);
+int vfio_container_dma_rw(struct vfio_container *container, dma_addr_t iova,
+			  void *data, size_t len, bool write);
+
 int __init vfio_container_init(void);
 void vfio_container_cleanup(void);
 
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index a74c34232c03..fd5e969ab653 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -770,7 +770,7 @@ out_unlock:
 static const struct file_operations vfio_device_fops;
 
 /* true if the vfio_device has open_device() called but not close_device() */
-bool vfio_assert_device_open(struct vfio_device *device)
+static bool vfio_assert_device_open(struct vfio_device *device)
 {
 	return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
 }
@@ -1877,6 +1877,126 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
 
 /*
+ * Pin contiguous user pages and return their associated host pages for local
+ * domain only.
+ * @device [in]  : device
+ * @iova [in]    : starting IOVA of user pages to be pinned.
+ * @npage [in]   : count of pages to be pinned.  This count should not
+ *		   be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
+ * @prot [in]    : protection flags
+ * @pages[out]   : array of host pages
+ * Return error or number of pages pinned.
+ *
+ * A driver may only call this function if the vfio_device was created
+ * by vfio_register_emulated_iommu_dev() due to vfio_container_pin_pages().
+ */
+int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
+		   int npage, int prot, struct page **pages)
+{
+	/* group->container cannot change while a vfio device is open */
+	if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device)))
+		return -EINVAL;
+	if (device->group->container)
+		return vfio_container_pin_pages(device->group->container,
+						device->group->iommu_group,
+						iova, npage, prot, pages);
+	if (device->iommufd_access) {
+		int ret;
+
+		if (iova > ULONG_MAX)
+			return -EINVAL;
+		/*
+		 * VFIO ignores the sub page offset, npages is from the start of
+		 * a PAGE_SIZE chunk of IOVA. The caller is expected to recover
+		 * the sub page offset by doing:
+		 *     pages[0] + (iova % PAGE_SIZE)
+		 */
+		ret = iommufd_access_pin_pages(
+			device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE),
+			npage * PAGE_SIZE, pages,
+			(prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0);
+		if (ret)
+			return ret;
+		return npage;
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL(vfio_pin_pages);
+
+/*
+ * Unpin contiguous host pages for local domain only.
+ * @device [in]  : device
+ * @iova [in]    : starting address of user pages to be unpinned.
+ * @npage [in]   : count of pages to be unpinned.  This count should not
+ *                 be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
+ */
+void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
+{
+	if (WARN_ON(!vfio_assert_device_open(device)))
+		return;
+
+	if (device->group->container) {
+		vfio_container_unpin_pages(device->group->container, iova,
+					   npage);
+		return;
+	}
+	if (device->iommufd_access) {
+		if (WARN_ON(iova > ULONG_MAX))
+			return;
+		iommufd_access_unpin_pages(device->iommufd_access,
+					   ALIGN_DOWN(iova, PAGE_SIZE),
+					   npage * PAGE_SIZE);
+		return;
+	}
+}
+EXPORT_SYMBOL(vfio_unpin_pages);
+
+/*
+ * This interface allows the CPUs to perform some sort of virtual DMA on
+ * behalf of the device.
+ *
+ * CPUs read/write from/into a range of IOVAs pointing to user space memory
+ * into/from a kernel buffer.
+ *
+ * As the read/write of user space memory is conducted via the CPUs and is
+ * not a real device DMA, it is not necessary to pin the user space memory.
+ *
+ * @device [in]		: VFIO device
+ * @iova [in]		: base IOVA of a user space buffer
+ * @data [in]		: pointer to kernel buffer
+ * @len [in]		: kernel buffer length
+ * @write		: indicate read or write
+ * Return error code on failure or 0 on success.
+ */
+int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
+		size_t len, bool write)
+{
+	if (!data || len <= 0 || !vfio_assert_device_open(device))
+		return -EINVAL;
+
+	if (device->group->container)
+		return vfio_container_dma_rw(device->group->container, iova,
+					     data, len, write);
+
+	if (device->iommufd_access) {
+		unsigned int flags = 0;
+
+		if (iova > ULONG_MAX)
+			return -EINVAL;
+
+		/* VFIO historically tries to auto-detect a kthread */
+		if (!current->mm)
+			flags |= IOMMUFD_ACCESS_RW_KTHREAD;
+		if (write)
+			flags |= IOMMUFD_ACCESS_RW_WRITE;
+		return iommufd_access_rw(device->iommufd_access, iova, data,
+					 len, flags);
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL(vfio_dma_rw);
+
+/*
  * Module/class support
  */
 static char *vfio_devnode(struct device *dev, umode_t *mode)