> From: Jason Gunthorpe <[email protected]> > Sent: Saturday, November 8, 2025 12:50 AM > > Once a DMABUF is revoked the domain will be unmapped under the pages > mutex. Double unmapping will trigger a WARN, and mapping while revoked > will fail. > > Check for revoked DMABUFs along all the map and unmap paths to resolve > this. Ensure that map/unmap is always done under the pages mutex so it is > synchronized with the revoke notifier. > > If a revoke happens between allocating the iopt_pages and the population > to a domain then the population will succeed, and leave things unmapped as > though revoke had happened immediately after. > > Currently there is no way to repopulate the domains. Userspace is expected > to know if it is going to do something that would trigger revoke (eg if it > is about to do a FLR) then it should go and remove the DMABUF mappings > before and put the back after. The revoke is only to protect the kernel > from mis-behaving userspace. > > Signed-off-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
