[PATCH] KVM: MMU: Detect oom conditions and propagate error to userspace

[pandora-kernel.git] / drivers / kvm / mmu.c

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index e96362a..7761089 100644 (file)
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -166,19 +166,20 @@ static int is_rmap_pte(u64 pte)
                == (PT_WRITABLE_MASK | PT_PRESENT_MASK);
 }
 
-static void mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
-                                  size_t objsize, int min)
+static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
+                                 size_t objsize, int min)
 {
        void *obj;
 
        if (cache->nobjs >= min)
-               return;
+               return 0;
        while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
                obj = kzalloc(objsize, GFP_NOWAIT);
                if (!obj)
-                       BUG();
+                       return -ENOMEM;
                cache->objects[cache->nobjs++] = obj;
        }
+       return 0;
 }
 
 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
@@ -187,12 +188,18 @@ static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
                kfree(mc->objects[--mc->nobjs]);
 }
 
-static void mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
+static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 {
-       mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
-                              sizeof(struct kvm_pte_chain), 4);
-       mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
-                              sizeof(struct kvm_rmap_desc), 1);
+       int r;
+
+       r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
+                                  sizeof(struct kvm_pte_chain), 4);
+       if (r)
+               goto out;
+       r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
+                                  sizeof(struct kvm_rmap_desc), 1);
+out:
+       return r;
 }
 
 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
@@ -824,8 +831,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
 {
        gpa_t addr = gva;
        hpa_t paddr;
+       int r;
 
-       mmu_topup_memory_caches(vcpu);
+       r = mmu_topup_memory_caches(vcpu);
+       if (r)
+               return r;
 
        ASSERT(vcpu);
        ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
@@ -1052,7 +1062,7 @@ int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
        r = init_kvm_mmu(vcpu);
        if (r < 0)
                goto out;
-       mmu_topup_memory_caches(vcpu);
+       r = mmu_topup_memory_caches(vcpu);
 out:
        return r;
 }