unsigned long data)
{
u64 *sptep;
- struct rmap_iterator iter;
+ struct rmap_iterator uninitialized_var(iter);
int young = 0;
/*
- * Emulate the accessed bit for EPT, by checking if this page has
+ * In case of absence of EPT Access and Dirty Bits supports,
+ * emulate the accessed bit for EPT, by checking if this page has
* an EPT mapping, and clearing it if it does. On the next access,
* a new EPT mapping will be established.
* This has some overhead, but not as much as the cost of swapping
for (sptep = rmap_get_first(*rmapp, &iter); sptep;
sptep = rmap_get_next(&iter)) {
- BUG_ON(!(*sptep & PT_PRESENT_MASK));
+ BUG_ON(!is_shadow_present_pte(*sptep));
- if (*sptep & PT_ACCESSED_MASK) {
+ if (*sptep & shadow_accessed_mask) {
young = 1;
- clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)sptep);
+ clear_bit((ffs(shadow_accessed_mask) - 1),
+ (unsigned long *)sptep);
}
}
for (sptep = rmap_get_first(*rmapp, &iter); sptep;
sptep = rmap_get_next(&iter)) {
- BUG_ON(!(*sptep & PT_PRESENT_MASK));
+ BUG_ON(!is_shadow_present_pte(*sptep));
- if (*sptep & PT_ACCESSED_MASK) {
+ if (*sptep & shadow_accessed_mask) {
young = 1;
break;
}
static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
{
struct kvm *kvm;
- struct kvm *kvm_freed = NULL;
int nr_to_scan = sc->nr_to_scan;
if (nr_to_scan == 0)
int idx;
LIST_HEAD(invalid_list);
+ /*
+ * n_used_mmu_pages is accessed without holding kvm->mmu_lock
+ * here. We may skip a VM instance errorneosly, but we do not
+ * want to shrink a VM that only started to populate its MMU
+ * anyway.
+ */
+ if (kvm->arch.n_used_mmu_pages > 0) {
+ if (!nr_to_scan--)
+ break;
+ continue;
+ }
+
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
- if (!kvm_freed && nr_to_scan > 0 &&
- kvm->arch.n_used_mmu_pages > 0) {
- kvm_mmu_remove_some_alloc_mmu_pages(kvm,
- &invalid_list);
- kvm_freed = kvm;
- }
- nr_to_scan--;
+ kvm_mmu_remove_some_alloc_mmu_pages(kvm, &invalid_list);
kvm_mmu_commit_zap_page(kvm, &invalid_list);
+
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
+
+ list_move_tail(&kvm->vm_list, &vm_list);
+ break;
}
- if (kvm_freed)
- list_move_tail(&kvm_freed->vm_list, &vm_list);
raw_spin_unlock(&kvm_lock);