David Hildenbrand
2021-May-03 08:11 UTC
[PATCH v1 5/7] mm: introduce page_offline_(begin|end|freeze|unfreeze) to synchronize setting PageOffline()
On 02.05.21 08:33, Mike Rapoport wrote:> On Thu, Apr 29, 2021 at 02:25:17PM +0200, David Hildenbrand wrote: >> A driver might set a page logically offline -- PageOffline() -- and >> turn the page inaccessible in the hypervisor; after that, access to page >> content can be fatal. One example is virtio-mem; while unplugged memory >> -- marked as PageOffline() can currently be read in the hypervisor, this >> will no longer be the case in the future; for example, when having >> a virtio-mem device backed by huge pages in the hypervisor. >> >> Some special PFN walkers -- i.e., /proc/kcore -- read content of random >> pages after checking PageOffline(); however, these PFN walkers can race >> with drivers that set PageOffline(). >> >> Let's introduce page_offline_(begin|end|freeze|unfreeze) for > > Bikeshed: freeze|thaw? >Sure :) -- Thanks, David / dhildenb