lkml.org 
[lkml]   [2022]   [May]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v1] vdpa: Warn if MTU configured is too low
Date
Following the recommendation in virio spec 1.1, a device offering
VIRTIO_NET_F_MTU should set the mtu to at least 1280 bytes.

Print a warning if this recommendation is not met.

Signed-off-by: Eli Cohen <elic@nvidia.com>
---
v0 -> v1:
chage pr_warn to netlink warning to userspace

drivers/vdpa/vdpa.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 91f4c13c7c7c..0fb4a615f267 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -583,6 +583,9 @@ vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU) | \
BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP))

+/* Recommended virtio spec 1.1 section 5.1.4.1 */
+#define VIRTIO_MIN_PREFERRED_MTU 1280
+
static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
{
struct vdpa_dev_set_config config = {};
@@ -634,6 +637,10 @@ static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *i
err = PTR_ERR(mdev);
goto err;
}
+ if ((mdev->supported_features & BIT_ULL(VIRTIO_NET_F_MTU)) &&
+ (config.mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU) &&
+ config.net.mtu < VIRTIO_MIN_PREFERRED_MTU))
+ NL_SET_ERR_MSG_MOD(info->extack, "MTU is below recommended value\n");
if ((config.mask & mdev->config_attr_mask) != config.mask) {
NL_SET_ERR_MSG_MOD(info->extack,
"All provided attributes are not supported");
@@ -1135,7 +1142,7 @@ static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
[VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
/* virtio spec 1.1 section 5.1.4.1 for valid MTU range */
- [VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68),
+ [VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, ETH_MIN_MTU),
};

static const struct genl_ops vdpa_nl_ops[] = {
--
2.35.1
\
 
 \ /
  Last update: 2022-05-11 12:58    [W:0.065 / U:1.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site