From 6ce1f4e295dd06b19443341b1684d361739ec117 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Wed, 13 May 2015 14:42:22 +0800 Subject: [PATCH] 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: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 97 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 75 insertions(+), 22 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index b1f5f09..316c432 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1412,6 +1412,74 @@ restart: 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; -- 2.7.4