KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start()

Remove gfn_to_pfn_cache_invalidate_start()'s unused @may_block parameter,
which was leftover from KVM's abandoned (for now) attempt to support guest
usage of gfn_to_pfn caches.

Fixes: a4bff3df51 ("KVM: pfncache: remove KVM_GUEST_USES_PFN usage")
Reported-by: Like Xu <like.xu.linux@gmail.com>
Cc: Paul Durrant <paul@xen.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240305003742.245767-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

virt/kvm/kvm_main.c

@@ -832,8 +832,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 	 * mn_active_invalidate_count (see above) instead of
 	 * mmu_invalidate_in_progress.
 	 */
-	gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end,
-					  hva_range.may_block);
+	gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end);
 
 	/*
 	 * If one or more memslots were found and thus zapped, notify arch code

virt/kvm/kvm_mm.h

@@ -26,13 +26,11 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool interruptible,
 #ifdef CONFIG_HAVE_KVM_PFNCACHE
 void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm,
 				       unsigned long start,
-				       unsigned long end,
-				       bool may_block);
+				       unsigned long end);
 #else
 static inline void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm,
 						     unsigned long start,
-						     unsigned long end,
-						     bool may_block)
+						     unsigned long end)
 {
 }
 #endif /* HAVE_KVM_PFNCACHE */

virt/kvm/pfncache.c

@@ -23,7 +23,7 @@
  * MMU notifier 'invalidate_range_start' hook.
  */
 void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm, unsigned long start,
-				       unsigned long end, bool may_block)
+				       unsigned long end)
 {
 	struct gfn_to_pfn_cache *gpc;