[PATCH v1 05/14] vfio: Create a vfio_device from vma lookup
From: Alex Williamson <hidden>
Date: 2021-03-08 21:48:49
Also in:
lkml
Subsystem:
the rest, vfio driver · Maintainers:
Linus Torvalds, Alex Williamson
Creating an address space mapping onto our vfio pseudo fs for each device file descriptor means that we can universally retrieve a vfio_device from a vma mapping this file. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Alex Williamson <redacted> --- drivers/vfio/vfio.c | 19 +++++++++++++++++-- include/linux/vfio.h | 1 + 2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 3852e57b9e04..3a3e85a0dc3e 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c@@ -927,6 +927,23 @@ struct vfio_device *vfio_device_get_from_dev(struct device *dev) } EXPORT_SYMBOL_GPL(vfio_device_get_from_dev); +static const struct file_operations vfio_device_fops; + +struct vfio_device *vfio_device_get_from_vma(struct vm_area_struct *vma) +{ + struct vfio_device *device; + + if (!vma->vm_file || vma->vm_file->f_op != &vfio_device_fops) + return ERR_PTR(-ENODEV); + + device = vma->vm_file->private_data; + + vfio_device_get(device); + + return device; +} +EXPORT_SYMBOL_GPL(vfio_device_get_from_vma); + static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, char *buf) {
@@ -1486,8 +1503,6 @@ static int vfio_group_add_container_user(struct vfio_group *group) return 0; } -static const struct file_operations vfio_device_fops; - static int vfio_group_get_device_fd(struct vfio_group *group, char *buf) { struct vfio_device *device;
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index f435dfca15eb..660b8adf90a6 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h@@ -58,6 +58,7 @@ extern void vfio_device_put(struct vfio_device *device); extern void *vfio_device_data(struct vfio_device *device); extern void vfio_device_unmap_mapping_range(struct vfio_device *device, loff_t start, loff_t len); +extern struct vfio_device *vfio_device_get_from_vma(struct vm_area_struct *vma); /* events for the backend driver notify callback */ enum vfio_iommu_notify_type {