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authorAlex Williamson <alex.williamson@redhat.com>2016-02-23 02:02:30 +0300
committerAlex Williamson <alex.williamson@redhat.com>2016-02-23 02:10:08 +0300
commit7c435b46c29a0240616cd1ad15d23341f9a341f4 (patch)
tree11d934d01e8efa1deb8c9bf29e7f84d3362ba98a
parentb95d9305e8cb8d432ca02da1b759fef59bc50ace (diff)
downloadlinux-7c435b46c29a0240616cd1ad15d23341f9a341f4.tar.xz
vfio: If an IOMMU backend fails, keep looking
Consider an IOMMU to be an API rather than an implementation, we might have multiple implementations supporting the same API, so try another if one fails. The expectation here is that we'll really only have one implementation per device type. For instance the existing type1 driver works with any PCI device where the IOMMU API is available. A vGPU vendor may have a virtual PCI device which provides DMA isolation and mapping through other mechanisms, but can re-use userspaces that make use of the type1 VFIO IOMMU API. This allows that to work. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
-rw-r--r--drivers/vfio/vfio.c16
1 files changed, 6 insertions, 10 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index ecca316386f5..4cc961b894af 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1080,30 +1080,26 @@ static long vfio_ioctl_set_iommu(struct vfio_container *container,
continue;
}
- /* module reference holds the driver we're working on */
- mutex_unlock(&vfio.iommu_drivers_lock);
-
data = driver->ops->open(arg);
if (IS_ERR(data)) {
ret = PTR_ERR(data);
module_put(driver->ops->owner);
- goto skip_drivers_unlock;
+ continue;
}
ret = __vfio_container_attach_groups(container, driver, data);
- if (!ret) {
- container->iommu_driver = driver;
- container->iommu_data = data;
- } else {
+ if (ret) {
driver->ops->release(data);
module_put(driver->ops->owner);
+ continue;
}
- goto skip_drivers_unlock;
+ container->iommu_driver = driver;
+ container->iommu_data = data;
+ break;
}
mutex_unlock(&vfio.iommu_drivers_lock);
-skip_drivers_unlock:
up_write(&container->group_lock);
return ret;