KVM: use slowpath for cross page cached accesses

kvm_write_guest_cached() does not mark all written pages as dirty and code comments in kvm_gfn_to_hva_cache_init() talk about NULL memslot with cross page accesses. Fix all the easy way. The check is '<= 1' to have the same result for 'len = 0' cache anywhere in the page. (nr_pages_needed is 0 on page boundary.) Fixes: 8f96452 ("KVM: Allow cross page reads and writes from cached translations.") Signed-off-by: Radim Krčmář <[email protected]> Message-Id: <[email protected]> Reviewed-by: Wanpeng Li <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
CamonZ · Apr 10, 2015 · ca3f087 · ca3f087
1 parent 3ea3b7f
commit ca3f087
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
@@ -1637,8 +1637,8 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
 	ghc->generation = slots->generation;
 	ghc->len = len;
 	ghc->memslot = gfn_to_memslot(kvm, start_gfn);
-	ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail);
-	if (!kvm_is_error_hva(ghc->hva) && nr_pages_avail >= nr_pages_needed) {
+	ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
+	if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
 		ghc->hva += offset;
 	} else {
 		/*