From: Nicolin Chen nicolinc@nvidia.com Sent: Wednesday, February 8, 2023 5:18 AM
Support an access->ioas replacement in iommufd_access_set_ioas(), which sets the access->ioas to NULL provisionally so that any further incoming iommufd_access_pin_pages() callback can be blocked.
Then, call access->ops->unmap() to clean up the entire iopt. To allow an iommufd_access_unpin_pages() callback to happen via this unmap() call, add an ioas_unpin pointer so the unpin routine won't be affected by the "access->ioas = NULL" trick above.
Suggested-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com
move patch10 before this one.
drivers/iommu/iommufd/device.c | 16 ++++++++++++++-- drivers/iommu/iommufd/iommufd_private.h | 1 + 2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index f4bd6f532a90..10ce47484ffa 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -509,11 +509,23 @@ int iommufd_access_set_ioas(struct iommufd_access *access, u32 ioas_id) iommufd_ref_to_users(obj); }
- /*
* Set ioas to NULL to block any further iommufd_access_pin_pages().* iommufd_access_unpin_pages() can continue using access-ioas_unpin.
*/- access->ioas = NULL;
- if (cur_ioas) {
if (new_ioas) {mutex_unlock(&access->ioas_lock);access->ops->unmap(access->data, 0, ULONG_MAX);mutex_lock(&access->ioas_lock);}
why does above only apply to a valid new_ioas? this is the cleanup on cur_ioas then required even when new_ioas=NULL.
Instead here the check should be "if (access->ops->unmap)". with patch10 the cleanup is required only for driver which is allowed to pin pages.