drm/virtio: use kvmalloc for large allocations

stable inclusion
from stable-5.10.21
commit 63d0afae74c4335b7ede9de92a3f8687ab987378
bugzilla: 50609

--------------------------------

commit ea86f3de upstream.

We observed that some of virtio_gpu_object_shmem_init() allocations
can be rather costly - order 6 - which can be difficult to fulfill
under memory pressure conditions. Switch to kvmalloc_array() in
virtio_gpu_object_shmem_init() and let the kernel vmalloc the entries
array.
Signed-off-by: NSergey Senozhatsky <senozhatsky@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20201105014744.1662226-1-senozhatsky@chromium.orgSigned-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NDoug Horn <doughorn@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/gpu/drm/virtio/virtgpu_object.c

@@ -172,8 +172,9 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 		*nents = shmem->pages->orig_nents;
 	}
 
-	*ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry),
-			      GFP_KERNEL);
+	*ents = kvmalloc_array(*nents,
+			       sizeof(struct virtio_gpu_mem_entry),
+			       GFP_KERNEL);
 	if (!(*ents)) {
 		DRM_ERROR("failed to allocate ent list\n");
 		return -ENOMEM;