On Fri, Aug 12, 2011 at 07:38:54AM +0200, Alexander Graf wrote: > > Am 12.08.2011 um 05:35 schrieb David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>: > > > On Tue, Aug 09, 2011 at 06:31:45PM +0200, Alexander Graf wrote: > >> When running a PAPR guest, we need to handle a few hypercalls in kernel space, > >> most prominently the page table invalidation (to sync the shadows). > >> > >> So this patch adds handling for a few PAPR hypercalls to PR mode KVM. I tried > >> to share the code with HV mode, but it ended up being a lot easier this way > >> around, as the two differ too much in those details. > > > > Are these strictly necessary, or just an optimization? Because you're > > using the space allocated by qemu for the guest hash table, it seems > > to be you could just let h_enter fall through to qemu which will put > > the right thing into the guest hash table which you can then walk in > > the kernel translation code. > > Every time a PTE can be invalidated, we need to do so in kvm to keep > the SPT in sync. IIRC h_enter can evict/overwrite a previous entry, > so we need to handle it in kvm as well :). Removal definitely needs > to happin in-kernel. True. I think you could actually delay this invalidation until the guest issues the tlbie, but it's probably not worth it. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson -- 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
