kvm: svm: Add memcg accounting to KVM allocations

There are many KVM kernel memory allocations which are tied to the life of
the VM process and should be charged to the VM process's cgroup. If the
allocations aren't tied to the process, the OOM killer will not know
that killing the process will free the associated kernel memory.
Add __GFP_ACCOUNT flags to many of the allocations which are not yet being
charged to the VM process's cgroup.

Tested:
	Ran all kvm-unit-tests on a 64 bit Haswell machine, the patch
	introduced no new failures.
	Ran a kernel memory accounting test which creates a VM to touch
	memory and then checks that the kernel memory allocated for the
	process is within certain bounds.
	With this patch we account for much more of the vmalloc and slab memory
	allocated for the VM.
Signed-off-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm.c

@@ -1795,9 +1795,10 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
 	/* Avoid using vmalloc for smaller buffers. */
 	size = npages * sizeof(struct page *);
 	if (size > PAGE_SIZE)
-		pages = vmalloc(size);
+		pages = __vmalloc(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO,
+				  PAGE_KERNEL);
 	else
-		pages = kmalloc(size, GFP_KERNEL);
+		pages = kmalloc(size, GFP_KERNEL_ACCOUNT);
 
 	if (!pages)
 		return NULL;
@@ -1865,7 +1866,9 @@ static void __unregister_enc_region_locked(struct kvm *kvm,
 
 static struct kvm *svm_vm_alloc(void)
 {
-	struct kvm_svm *kvm_svm = vzalloc(sizeof(struct kvm_svm));
+	struct kvm_svm *kvm_svm = __vmalloc(sizeof(struct kvm_svm),
+					    GFP_KERNEL_ACCOUNT | __GFP_ZERO,
+					    PAGE_KERNEL);
 	return &kvm_svm->kvm;
 }
 
@@ -1940,7 +1943,7 @@ static int avic_vm_init(struct kvm *kvm)
 		return 0;
 
 	/* Allocating physical APIC ID table (4KB) */
-	p_page = alloc_page(GFP_KERNEL);
+	p_page = alloc_page(GFP_KERNEL_ACCOUNT);
 	if (!p_page)
 		goto free_avic;
 
@@ -1948,7 +1951,7 @@ static int avic_vm_init(struct kvm *kvm)
 	clear_page(page_address(p_page));
 
 	/* Allocating logical APIC ID table (4KB) */
-	l_page = alloc_page(GFP_KERNEL);
+	l_page = alloc_page(GFP_KERNEL_ACCOUNT);
 	if (!l_page)
 		goto free_avic;
 
@@ -2120,13 +2123,14 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
 	struct page *nested_msrpm_pages;
 	int err;
 
-	svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
+	svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT);
 	if (!svm) {
 		err = -ENOMEM;
 		goto out;
 	}
 
-	svm->vcpu.arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache, GFP_KERNEL);
+	svm->vcpu.arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
+						     GFP_KERNEL_ACCOUNT);
 	if (!svm->vcpu.arch.guest_fpu) {
 		printk(KERN_ERR "kvm: failed to allocate vcpu's fpu\n");
 		err = -ENOMEM;
@@ -2138,19 +2142,19 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
 		goto free_svm;
 
 	err = -ENOMEM;
-	page = alloc_page(GFP_KERNEL);
+	page = alloc_page(GFP_KERNEL_ACCOUNT);
 	if (!page)
 		goto uninit;
 
-	msrpm_pages = alloc_pages(GFP_KERNEL, MSRPM_ALLOC_ORDER);
+	msrpm_pages = alloc_pages(GFP_KERNEL_ACCOUNT, MSRPM_ALLOC_ORDER);
 	if (!msrpm_pages)
 		goto free_page1;
 
-	nested_msrpm_pages = alloc_pages(GFP_KERNEL, MSRPM_ALLOC_ORDER);
+	nested_msrpm_pages = alloc_pages(GFP_KERNEL_ACCOUNT, MSRPM_ALLOC_ORDER);
 	if (!nested_msrpm_pages)
 		goto free_page2;
 
-	hsave_page = alloc_page(GFP_KERNEL);
+	hsave_page = alloc_page(GFP_KERNEL_ACCOUNT);
 	if (!hsave_page)
 		goto free_page3;
 
@@ -5192,7 +5196,7 @@ static int svm_ir_list_add(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi)
 	 * Allocating new amd_iommu_pi_data, which will get
 	 * add to the per-vcpu ir_list.
 	 */
-	ir = kzalloc(sizeof(struct amd_svm_iommu_ir), GFP_KERNEL);
+	ir = kzalloc(sizeof(struct amd_svm_iommu_ir), GFP_KERNEL_ACCOUNT);
 	if (!ir) {
 		ret = -ENOMEM;
 		goto out;
@@ -6307,7 +6311,7 @@ static int sev_bind_asid(struct kvm *kvm, unsigned int handle, int *error)
 	if (ret)
 		return ret;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		return -ENOMEM;
 
@@ -6357,7 +6361,7 @@ static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
 		return -EFAULT;
 
-	start = kzalloc(sizeof(*start), GFP_KERNEL);
+	start = kzalloc(sizeof(*start), GFP_KERNEL_ACCOUNT);
 	if (!start)
 		return -ENOMEM;
 
@@ -6454,7 +6458,7 @@ static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data, sizeof(params)))
 		return -EFAULT;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		return -ENOMEM;
 
@@ -6531,7 +6535,7 @@ static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (copy_from_user(&params, measure, sizeof(params)))
 		return -EFAULT;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		return -ENOMEM;
 
@@ -6593,7 +6597,7 @@ static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (!sev_guest(kvm))
 		return -ENOTTY;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		return -ENOMEM;
 
@@ -6614,7 +6618,7 @@ static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (!sev_guest(kvm))
 		return -ENOTTY;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		return -ENOMEM;
 
@@ -6642,7 +6646,7 @@ static int __sev_issue_dbg_cmd(struct kvm *kvm, unsigned long src,
 	struct sev_data_dbg *data;
 	int ret;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		return -ENOMEM;
 
@@ -6897,7 +6901,7 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	}
 
 	ret = -ENOMEM;
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		goto e_unpin_memory;
 
@@ -7003,7 +7007,7 @@ static int svm_register_enc_region(struct kvm *kvm,
 	if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
 		return -EINVAL;
 
-	region = kzalloc(sizeof(*region), GFP_KERNEL);
+	region = kzalloc(sizeof(*region), GFP_KERNEL_ACCOUNT);
 	if (!region)
 		return -ENOMEM;