On Fri, Apr 08, 2022 at 09:02:54PM +0800, Chao Peng wrote: > > I think the correct approach is to not do the locking automatically for SHM_F_INACCESSIBLE, > > and instead require userspace to do shmctl(.., SHM_LOCK, ...) if userspace knows the > > consumers don't support migrate/swap. That'd require wrapping migrate_page() and then > > wiring up notifier hooks for migrate/swap, but IMO that's a good thing to get sorted > > out sooner than later. KVM isn't planning on support migrate/swap for TDX or SNP, > > but supporting at least migrate for a software-only implementation a la pKVM should > > be relatively straightforward. On the notifiee side, KVM can terminate the VM if it > > gets an unexpected migrate/swap, e.g. so that TDX/SEV VMs don't die later with > > exceptions and/or data corruption (pre-SNP SEV guests) in the guest. > > SHM_LOCK sounds like a good match. Emm, no. shmctl(2) and SHM_LOCK are SysV IPC thing. I don't see how they fit here. -- Kirill A. Shutemov
