KVM: Retry sleeping allocation if atomic allocation fails
This avoids -ENOMEM under memory pressure.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index a368ea8..c814394 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -199,14 +199,15 @@
}
static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
- struct kmem_cache *base_cache, int min)
+ struct kmem_cache *base_cache, int min,
+ gfp_t gfp_flags)
{
void *obj;
if (cache->nobjs >= min)
return 0;
while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
- obj = kmem_cache_zalloc(base_cache, GFP_NOWAIT);
+ obj = kmem_cache_zalloc(base_cache, gfp_flags);
if (!obj)
return -ENOMEM;
cache->objects[cache->nobjs++] = obj;
@@ -220,20 +221,35 @@
kfree(mc->objects[--mc->nobjs]);
}
-static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
+static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags)
{
int r;
r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
- pte_chain_cache, 4);
+ pte_chain_cache, 4, gfp_flags);
if (r)
goto out;
r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
- rmap_desc_cache, 1);
+ rmap_desc_cache, 1, gfp_flags);
out:
return r;
}
+static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
+{
+ int r;
+
+ r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
+ if (r < 0) {
+ spin_unlock(&vcpu->kvm->lock);
+ kvm_arch_ops->vcpu_put(vcpu);
+ r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
+ kvm_arch_ops->vcpu_load(vcpu);
+ spin_lock(&vcpu->kvm->lock);
+ }
+ return r;
+}
+
static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
{
mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);