4 Nov
2022
4 Nov
'22
7:42 p.m.
On Fri, Nov 04, 2022 at 05:43:29AM +0000, Tian, Kevin wrote:
From: Jason Gunthorpe jgg@nvidia.com Sent: Friday, November 4, 2022 9:01 AM
The only way I can see to solve this is to hold a serializing lock across iommufd_access_pin_pages() so that neither iommufd_test_access_unmap() can progress until both the pin is completed and the record of the pin is stored.
same as gvt does which maintains an internal mapping cache and conducts pin/unmap with cache update under the mutex protection.
Yeah, that does actually look OK
Jason