On 2013-09-02 20:09, Gleb Natapov wrote: > On Mon, Sep 02, 2013 at 07:58:30PM +0200, Jan Kiszka wrote: >> On 2013-09-02 15:16, Gleb Natapov wrote: >>> On Thu, Aug 08, 2013 at 04:26:30PM +0200, Jan Kiszka wrote: >>>> We need to update EFER.NX before building the nEPT state via >>>> nested_ept_init_mmu_context. Otherwise, we risk to create an MMU context >>>> that claims to have NX disabled while the guest EPT used NX. This will >>>> cause spurious faults for L2. >>>> >>> Hmm, I do not see how nested ept mmu depends on guests EFER.NX setting. >>> It just sets mmu->nx to true. >> >> Don't ask me for the details behind this, but update_permission_bitmask >> called by kvm_init_shadow_ept_mmu is using it e.g. And the > It uses it only in !ept case though and never looks at a guest setting > as far as I can tell. Is it possible that this was an artifact of all > nEPT code and the latest one does not need this patch? Hmm, possibly. Let me recheck, hope I can find the reproduction pattern again... Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
