On Tue, Nov 23, 2021, Borislav Petkov wrote: > On Mon, Nov 22, 2021 at 02:51:35PM -0800, Dave Hansen wrote: > > By "supporting", do you mean doing something functional? I don't really > > care if ptrace() to guest private memory returns -EINVAL or whatever. > > The most important thing is not crashing the host. > > > > Also, as Sean mentioned, this isn't really about ptrace() itself. It's > > really about ensuring that no kernel or devices accesses to guest > > private memory can induce bad behavior. > > I keep repeating this suggestion of mine that we should treat > guest-private pages as hw-poisoned pages which have experienced a > uncorrectable error in the past. > > mm already knows how to stay away from those. Kirill posted a few RFCs that did exactly that. It's definitely a viable approach, but it's a bit of a dead end, e.g. doesn't help solve page migration, is limited to struct page, doesn't capture which KVM guest owns the memory, etc... https://lore.kernel.org/kvm/20210416154106.23721-1-kirill.shutemov@xxxxxxxxxxxxxxx/
