On 11/17/2011 01:52 AM, Paul Mackerras wrote: > This implements the low-level functions called by the MMU notifiers in > the generic KVM code, and defines KVM_ARCH_WANT_MMU_NOTIFIER if > CONFIG_KVM_BOOK3S_64_HV so that the generic KVM MMU notifiers get > included. > > That means we also have to take notice of when PTE invalidations are > in progress, as indicated by mmu_notifier_retry(). In kvmppc_h_enter, > if any invalidation is in progress we just install a non-present HPTE. > In kvmppc_book3s_hv_page_fault, if an invalidation is in progress we > just return without resolving the guest, causing it to encounter another > page fault immediately. This is better than spinning inside > kvmppc_book3s_hv_page_fault because this way the guest can get preempted > by a hypervisor decrementer interrupt without us having to do any > special checks. > > We currently maintain a referenced bit in the rmap array, and when we > clear it, we make all the HPTEs that map the corresponding page be > non-present, as if the page were invalidated. In future we could use > the hardware reference bit in the guest HPT instead. > > The kvm_set_spte_hva function is implemented as kvm_unmap_hva. The > former appears to be unused anyway. This is mostly used for COW (after ksm, not fork). So if you want to use ksm, this avoids an exit. > This all means that on processors that support virtual partition > memory (POWER7), we can claim support for the KVM_CAP_SYNC_MMU > capability, and we no longer have to pin all the guest memory. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
