> -----Original Message----- > From: Jan Beulich <[email protected]> > Sent: 20 October 2020 14:54 > To: [email protected] > Cc: Andrew Cooper <[email protected]>; Paul Durrant <[email protected]> > Subject: [PATCH] AMD/IOMMU: correct shattering of super pages > > Fill the new page table _before_ installing into a live page table > hierarchy, as installing a blank page first risks I/O faults on > sub-ranges of the original super page which aren't part of the range > for which mappings are being updated. > > While at it also do away with mapping and unmapping the same fresh > intermediate page table page once per entry to be written. > > Signed-off-by: Jan Beulich <[email protected]> > --- > Afaict this corrects presently dead code: I don't think there are ways > for super pages to be created in the first place, i.e. none could ever > need shattering.
I believe you are correct, yes. Certainly an improvement though so... Reviewed-by: Paul Durrant <[email protected]>
