On 14/11/2019 22:36, Tamas K Lengyel wrote: > On Thu, Nov 14, 2019 at 11:39 AM Andrew Cooper > <andrew.coop...@citrix.com> wrote: >> On 14/11/2019 18:34, Tamas K Lengyel wrote: >>> * Comments: All works, altp2m+introspection requires the ept=pml=0 >>> boot flag specified to workaround a deadlock in Xen >> Is this separate from the general problem with EPT A/D and >> write-protecting pagetables? >> > It sounds like it is, it happens without write-protecting in-guest > pagetables. I didn't have time to investigate where the deadlock > happens and since the workaround is fine for the usecase it wasn't a > priority to figure out.
Thinking about it, PML will do the wrong thing (deadlocks aside) as soon as any altp2m gfn translations are used. I'd be tempted to work around the deadlock by disabling pml the moment altp2m is touched. That would give a sightly less bad user experience, and should be easy to sort for 4.13. Thoughts, (inc. Juergen as RM) ? ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel