KVM: PPC: Book3S PR: Reduce number of shadow PTEs invalidated by MMU notifiers

[~andy/linux] / arch / powerpc / kvm / book3s_pr.c

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 2f84ed807184b9f3dffac0ee7f5be3c350926a10..6075dbd0b364a9620592bb7f4f40a3f02289f0d7 100644 (file)
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -150,24 +150,48 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu)
 }
 
 /************* MMU Notifiers *************/
+static void do_kvm_unmap_hva(struct kvm *kvm, unsigned long start,
+                            unsigned long end)
+{
+       long i;
+       struct kvm_vcpu *vcpu;
+       struct kvm_memslots *slots;
+       struct kvm_memory_slot *memslot;
+
+       slots = kvm_memslots(kvm);
+       kvm_for_each_memslot(memslot, slots) {
+               unsigned long hva_start, hva_end;
+               gfn_t gfn, gfn_end;
+
+               hva_start = max(start, memslot->userspace_addr);
+               hva_end = min(end, memslot->userspace_addr +
+                                       (memslot->npages << PAGE_SHIFT));
+               if (hva_start >= hva_end)
+                       continue;
+               /*
+                * {gfn(page) | page intersects with [hva_start, hva_end)} =
+                * {gfn, gfn+1, ..., gfn_end-1}.
+                */
+               gfn = hva_to_gfn_memslot(hva_start, memslot);
+               gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
+               kvm_for_each_vcpu(i, vcpu, kvm)
+                       kvmppc_mmu_pte_pflush(vcpu, gfn << PAGE_SHIFT,
+                                             gfn_end << PAGE_SHIFT);
+       }
+}
 
 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 {
        trace_kvm_unmap_hva(hva);
 
-       /*
-        * Flush all shadow tlb entries everywhere. This is slow, but
-        * we are 100% sure that we catch the to be unmapped page
-        */
-       kvm_flush_remote_tlbs(kvm);
+       do_kvm_unmap_hva(kvm, hva, hva + PAGE_SIZE);
 
        return 0;
 }
 
 int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
 {
-       /* kvm_unmap_hva flushes everything anyways */
-       kvm_unmap_hva(kvm, start);
+       do_kvm_unmap_hva(kvm, start, end);
 
        return 0;
 }
@@ -187,7 +211,7 @@ int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
 {
        /* The page will get remapped properly on its next fault */
-       kvm_unmap_hva(kvm, hva);
+       do_kvm_unmap_hva(kvm, hva, hva + PAGE_SIZE);
 }
 
 /*****************************************/