[PATCH 2/6] vfio/iommu_type1: Ignore external domain when promote pinned_scope

From: Keqian Zhu
Date: Wed Jan 06 2021 - 23:45:50 EST


The pinned_scope of external domain's groups are always true, that's
to say we can safely ignore external domain when promote pinned_scope
status of vfio_iommu.

Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
---
drivers/vfio/vfio_iommu_type1.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 334a8240e1da..110ada24ee91 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1637,14 +1637,7 @@ static void promote_pinned_page_dirty_scope(struct vfio_iommu *iommu)
}
}

- if (iommu->external_domain) {
- domain = iommu->external_domain;
- list_for_each_entry(group, &domain->group_list, next) {
- if (!group->pinned_page_dirty_scope)
- return;
- }
- }
-
+ /* The external domain always passes check */
iommu->pinned_page_dirty_scope = true;
}

@@ -2347,7 +2340,6 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
if (iommu->external_domain) {
group = find_iommu_group(iommu->external_domain, iommu_group);
if (group) {
- promote_dirty_scope = !group->pinned_page_dirty_scope;
list_del(&group->next);
kfree(group);

@@ -2360,7 +2352,8 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
kfree(iommu->external_domain);
iommu->external_domain = NULL;
}
- goto detach_group_done;
+ mutex_unlock(&iommu->lock);
+ return;
}
}

@@ -2408,7 +2401,6 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
else
vfio_iommu_iova_free(&iova_copy);

-detach_group_done:
/*
* Removal of a group without dirty tracking may allow the iommu scope
* to be promoted.
--
2.19.1