[Intel-gfx] [PATCH v7 7/9] vfio: Add helper to search vfio_device in a dev_set

Yi Liu
2023-06-02T12:15:31Z

There are drivers that need to search vfio_device within a given dev_set.
e.g. vfio-pci. So add a helper.

vfio_pci_is_device_in_set() now returns -EBUSY in commit a882c16a2b7e
("vfio/pci: Change vfio_pci_try_bus_reset() to use the dev_set") where
it was trying to preserve the return of vfio_pci_try_zap_and_vma_lock_cb().
However, it makes more sense to return -ENODEV.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/pci/vfio_pci_core.c | 6 +-----
drivers/vfio/vfio_main.c | 15 +++++++++++++++
include/linux/vfio.h | 3 +++
3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 39e7823088e7..3a2f67675036 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -2335,12 +2335,8 @@ static bool vfio_dev_in_groups(struct vfio_pci_core_device *vdev,
static int vfio_pci_is_device_in_set(struct pci_dev *pdev, void *data)
{
struct vfio_device_set *dev_set = data;
- struct vfio_device *cur;

- list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
- if (cur->dev == &pdev->dev)
- return 0;
- return -EBUSY;
+ return vfio_find_device_in_devset(dev_set, &pdev->dev) ? 0 : -ENODEV;
}

/*
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index f0ca33b2e1df..ab4f3a794f78 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -141,6 +141,21 @@ unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
}
EXPORT_SYMBOL_GPL(vfio_device_set_open_count);

+struct vfio_device *
+vfio_find_device_in_devset(struct vfio_device_set *dev_set,
+ struct device *dev)
+{
+ struct vfio_device *cur;
+
+ lockdep_assert_held(&dev_set->lock);
+
+ list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
+ if (cur->dev == dev)
+ return cur;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_find_device_in_devset);
+
/*
* Device objects - create, release, get, put, search
*/
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 2a45853773a6..ee120d2d530b 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -244,6 +244,9 @@ void vfio_unregister_group_dev(struct vfio_device *device);

int vfio_assign_device_set(struct vfio_device *device, void *set_id);
unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);
+struct vfio_device *
+vfio_find_device_in_devset(struct vfio_device_set *dev_set,
+ struct device *dev);

int vfio_mig_get_next_state(struct vfio_device *device,
enum vfio_device_mig_state cur_fsm,
--
2.34.1