On Mon, Jan 12, 2015 at 08:14:12AM +0000, Ard Biesheuvel wrote: > On 11 January 2015 at 13:33, Christoffer Dall > <christoffer.dall@xxxxxxxxxx> wrote: > > Hi Ard and Marc, > > > > In KVM/ARM we are currently still checking kvm_is_device_pfn() in > > user_mem_abort(). But after Ard's commit (8eef912 arm/arm64: KVM: map > > MMIO regions at creation time), shouldn't we always create these > > mappings at memregion creation time and never fault here? > > > > Good question. My patch only ensures that VM_PFNMAP regions are stage2 > mapped right away, i.e., host mappings made via remap_pfn_range() > I wonder if there are other valid cases where a pfn without an > associated struct page could be part of a region that is exposed to > the guest by the host as a memslot. > Perhaps we should wait for the device passthrough stuff etc to > materialize before adding BUG()s like this? > I haven't been enable to decide one way or the other, so I agree, we should probably keep the code path as it is and Mario should adapt his patches accordingly (which means not setting IOMAP flags from user_mem_abort() and thus not having to worry about getting a NULL pmd back). -Christoffer _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
