Commit 6ce1f4e2 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Paolo Bonzini
Browse files

KVM: MMU: introduce for_each_slot_rmap_range 



It's used to abstract the code from kvm_handle_hva_range and it will be
used by later patch

Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8a3d08f1

arch/x86/kvm/mmu.c

+75 −22
Original line number Diff line number Diff line
@@ -1412,6 +1412,74 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, 
	return 0;

}



struct slot_rmap_walk_iterator {

	/* input fields. */

	struct kvm_memory_slot *slot;

	gfn_t start_gfn;

	gfn_t end_gfn;

	int start_level;

	int end_level;



	/* output fields. */

	gfn_t gfn;

	unsigned long *rmap;

	int level;



	/* private field. */

	unsigned long *end_rmap;

};



static void

rmap_walk_init_level(struct slot_rmap_walk_iterator *iterator, int level)

{

	iterator->level = level;

	iterator->gfn = iterator->start_gfn;

	iterator->rmap = __gfn_to_rmap(iterator->gfn, level, iterator->slot);

	iterator->end_rmap = __gfn_to_rmap(iterator->end_gfn, level,

					   iterator->slot);

}



static void

slot_rmap_walk_init(struct slot_rmap_walk_iterator *iterator,

		    struct kvm_memory_slot *slot, int start_level,

		    int end_level, gfn_t start_gfn, gfn_t end_gfn)

{

	iterator->slot = slot;

	iterator->start_level = start_level;

	iterator->end_level = end_level;

	iterator->start_gfn = start_gfn;

	iterator->end_gfn = end_gfn;



	rmap_walk_init_level(iterator, iterator->start_level);

}



static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator)

{

	return !!iterator->rmap;

}



static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator)

{

	if (++iterator->rmap <= iterator->end_rmap) {

		iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level));

		return;

	}



	if (++iterator->level > iterator->end_level) {

		iterator->rmap = NULL;

		return;

	}



	rmap_walk_init_level(iterator, iterator->level);

}



#define for_each_slot_rmap_range(_slot_, _start_level_, _end_level_,	\

	   _start_gfn, _end_gfn, _iter_)				\

	for (slot_rmap_walk_init(_iter_, _slot_, _start_level_,		\

				 _end_level_, _start_gfn, _end_gfn);	\

	     slot_rmap_walk_okay(_iter_);				\

	     slot_rmap_walk_next(_iter_))



static int kvm_handle_hva_range(struct kvm *kvm,

				unsigned long start,

				unsigned long end,
@@ -1423,10 +1491,10 @@ static int kvm_handle_hva_range(struct kvm *kvm, 
					       int level,

					       unsigned long data))

{

	int j;

	int ret = 0;

	struct kvm_memslots *slots;

	struct kvm_memory_slot *memslot;

	struct slot_rmap_walk_iterator iterator;

	int ret = 0;



	slots = kvm_memslots(kvm);
@@ -1446,26 +1514,11 @@ static int kvm_handle_hva_range(struct kvm *kvm, 
		gfn_start = hva_to_gfn_memslot(hva_start, memslot);

		gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);



		for (j = PT_PAGE_TABLE_LEVEL;

		     j <= PT_MAX_HUGEPAGE_LEVEL; ++j) {

			unsigned long idx, idx_end;

			unsigned long *rmapp;

			gfn_t gfn = gfn_start;



			/*

			 * {idx(page_j) | page_j intersects with

			 *  [hva_start, hva_end)} = {idx, idx+1, ..., idx_end}.

			 */

			idx = gfn_to_index(gfn_start, memslot->base_gfn, j);

			idx_end = gfn_to_index(gfn_end - 1, memslot->base_gfn, j);



			rmapp = __gfn_to_rmap(gfn_start, j, memslot);



			for (; idx <= idx_end;

			       ++idx, gfn += (1UL << KVM_HPAGE_GFN_SHIFT(j)))

				ret |= handler(kvm, rmapp++, memslot,

					       gfn, j, data);

		}

		for_each_slot_rmap_range(memslot, PT_PAGE_TABLE_LEVEL,

				PT_MAX_HUGEPAGE_LEVEL, gfn_start, gfn_end - 1,

				&iterator)

			ret |= handler(kvm, iterator.rmap, memslot,

				       iterator.gfn, iterator.level, data);

	}



	return ret;