[RFC v2 5/5] virtio/vsock: add sysfs for rx buf len for dgram

Jiang Wang
2021-09-14T05:56:03Z

Make rx buf len configurable via sysfs

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
---
net/vmw_vsock/virtio_transport.c | 46 ++++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 8d5bfcd79555..55216d979080 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -29,6 +29,16 @@ static struct virtio_vsock __rcu *the_virtio_vsock;
static struct virtio_vsock *the_virtio_vsock_dgram;
static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */

+static int rx_buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+static struct kobject *kobj_ref, *kobj_ref2;
+static ssize_t dgram_sysfs_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf);
+static ssize_t dgram_sysfs_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf,
+ size_t count);
+static struct kobj_attribute rxbuf_attr = __ATTR(dgram_rx_buf_size, 0660, dgram_sysfs_show,
+ dgram_sysfs_store);
+
struct virtio_vsock {
struct virtio_device *vdev;
struct virtqueue **vqs;
@@ -362,7 +372,7 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk)

static void virtio_vsock_rx_fill(struct virtio_vsock *vsock, bool is_dgram)
{
- int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+ int buf_len = rx_buf_len;
struct virtio_vsock_pkt *pkt;
struct scatterlist hdr, buf, *sgs[2];
struct virtqueue *vq;
@@ -1027,6 +1037,23 @@ static struct virtio_driver virtio_vsock_driver = {
.remove = virtio_vsock_remove,
};

+static ssize_t dgram_sysfs_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d", rx_buf_len);
+}
+
+static ssize_t dgram_sysfs_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf,
+ size_t count)
+{
+ if (kstrtou32(buf, 0, &rx_buf_len) < 0)
+ return -EINVAL;
+ if (rx_buf_len < 1024)
+ rx_buf_len = 1024;
+ return count;
+}
+
static int __init virtio_vsock_init(void)
{
int ret;
@@ -1044,8 +1071,19 @@ static int __init virtio_vsock_init(void)
if (ret)
goto out_vci;

- return 0;
+ kobj_ref = kobject_create_and_add("vsock", kernel_kobj);
+ kobj_ref2 = kobject_create_and_add("virtio", kobj_ref);
+
+ /*Creating sysfs file for etx_value*/
+ ret = sysfs_create_file(kobj_ref2, &rxbuf_attr.attr);
+ if (ret)
+ goto out_sysfs;

+ return 0;
+out_sysfs:
+ kobject_put(kobj_ref);
+ kobject_put(kobj_ref2);
+ sysfs_remove_file(kobj_ref2, &rxbuf_attr.attr);
out_vci:
vsock_core_unregister(&virtio_transport.transport);
out_wq:
@@ -1058,6 +1096,10 @@ static void __exit virtio_vsock_exit(void)
unregister_virtio_driver(&virtio_vsock_driver);
vsock_core_unregister(&virtio_transport.transport);
destroy_workqueue(virtio_vsock_workqueue);
+ kobject_put(kobj_ref);
+ kobject_put(kobj_ref2);
+ sysfs_remove_file(kobj_ref2, &rxbuf_attr.attr);
+
}

module_init(virtio_vsock_init);
--
2.20.1