"Jan Beulich" <jbeul...@suse.com> writes: >>>> On 03.06.15 at 15:35, <vkuzn...@redhat.com> wrote: >> When soft reset is being performed we need to replace all actively >> granted pages with empty pages to prevent possible future memory >> corruption as the newly started kernel won't be aware of these >> granted pages. >> >> We make the tot_pages < max_pages assumption here: previously granted pages >> need to belong to someone and we don't want to implement possible DoS by >> reassigning them to the grantee/anonymous domain/xen/.. (the malicious guest >> will be able to consume all host's memory). > > How is that going to look in practice? I.e. won't this cause frequent > failures? >
I'm not sure we actually need that in practice. In my testing backends (even with persistent grants enabled) collaborate nicely and release all grants. I can see a single page still being held and I suppose it's being held by QEMU (haven't checked what that but I think it is the console ring). In case we go for the toolstack-assisted approach we can restart qemu and add some warning when there are active grants. -- Vitaly _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
