提交 d91ffee9 编写于 作者: K Kai Huang 提交者: Paolo Bonzini

Optimize TLB flush in kvm_mmu_slot_remove_write_access.

No TLB flush is needed when there's no valid rmap in memory slot.
Signed-off-by: NKai Huang <kai.huang@linux.intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
上级 0c55d6d9
......@@ -4302,6 +4302,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
struct kvm_memory_slot *memslot;
gfn_t last_gfn;
int i;
bool flush = false;
memslot = id_to_memslot(kvm->memslots, slot);
last_gfn = memslot->base_gfn + memslot->npages - 1;
......@@ -4318,7 +4319,8 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
for (index = 0; index <= last_index; ++index, ++rmapp) {
if (*rmapp)
__rmap_write_protect(kvm, rmapp, false);
flush |= __rmap_write_protect(kvm, rmapp,
false);
if (need_resched() || spin_needbreak(&kvm->mmu_lock))
cond_resched_lock(&kvm->mmu_lock);
......@@ -4345,7 +4347,8 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
* instead of PT_WRITABLE_MASK, that means it does not depend
* on PT_WRITABLE_MASK anymore.
*/
kvm_flush_remote_tlbs(kvm);
if (flush)
kvm_flush_remote_tlbs(kvm);
}
#define BATCH_ZAP_PAGES 10
......
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