On Mon, 2021-09-27 at 14:34 -0700, Tony Luck wrote: > SGX EPC pages go through the following life cycle: > > DIRTY ---> FREE ---> IN-USE --\ > ^ | > \-----------------/ > > Recovery action for poison for a DIRTY or FREE page is simple. Just > make sure never to allocate the page. IN-USE pages need some extra > handling. > > Add a new flag bit SGX_EPC_PAGE_IN_USE that is set when a page > is allocated and cleared when the page is freed. > > Notes: > > 1) These transitions are made while holding the node->lock so that > future code that checks the flags while holding the node->lock > can be sure that if the SGX_EPC_PAGE_IN_USE bit is set, then the > page is on the free list. > > 2) Initially while the pages are on the dirty list the > SGX_EPC_PAGE_IN_USE bit is set. > > Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> /Jarkko
