From: souvikdey33 <sodey@sonusnet.com>
To: <dev@dpdk.org>, <stephen@networkplumber.org>,
<yuanhan.liu@linux.intel.com>, <mark.b.kavanagh@intel.com>
Cc: souvikdey33 <sodey@sonusnet.com>
Subject: [dpdk-dev] [PATCH v5]net/virtio: add mtu set in virtio
Date: Fri, 16 Sep 2016 13:13:57 -0400 [thread overview]
Message-ID: <20160916171357.69640-1-sodey@sonusnet.com> (raw)
Virtio interfaces should also support setting of mtu, as in case of cloud
it is expected to have the consistent mtu across the infrastructure that
the dhcp server sends and not hardcoded to 1500(default).
In case when GRE/VXLAN tunneling is used, it adds overheads to the total
size of 1518, and in that cases the DHCP server corrects the L3 MTU to 1454
to take care of the overhead. BUt since virtio interfaces was not having the
mtu set that mtu sent by dhcp was ignored and teh instance will still send
packets with 1500 mtu which afetr encapsulation will become more than 1518
and eventually gets dropped in the infrastructure. This issue can be solved
by honoring the mtu 1454 sent by dhcp server, which this below patch will
take care.
Changes in v5: Incorporated review comments.
Changes in v4: Incorporated review comments.
Changes in v3: Corrected few style errors as reported by sys-stv.
Changes in v2: Incorporated review comments.
Signed-off-by: Souvik Dey <sodey@sonusnet.com>
---
drivers/net/virtio/virtio_ethdev.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 07d6449..da16ad4 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -653,12 +653,20 @@ virtio_dev_allmulticast_disable(struct rte_eth_dev *dev)
PMD_INIT_LOG(ERR, "Failed to disable allmulticast");
}
+#define VLAN_TAG_SIZE 4 /* 802.3ac tag (not DMA'd) */
+
+static int virtio_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
+{
+ struct rte_eth_dev_info dev_info;
+ uint32_t ether_hdr_len = ETHER_HDR_LEN + ETHER_CRC_LEN + VLAN_TAG_SIZE;
+ uint32_t frame_size = mtu + ether_hdr_len;
+
+ virtio_dev_info_get(dev, &dev_info);
+
+ if (frame_size < ETHER_MIN_MTU || frame_size > dev_info.max_rx_pktlen) {
+ PMD_INIT_LOG(ERR, "MTU should be between %d and %d\n",
+ (ETHER_MIN_MTU - ether_hdr_len),
+ (dev_info.max_rx_pktlen - ether_hdr_len));
+ return -EINVAL;
+ }
+ return 0;
+}
@@ -677,7 +685,6 @@ static const struct eth_dev_ops virtio_eth_dev_ops = {
.allmulticast_enable = virtio_dev_allmulticast_enable,
.allmulticast_disable = virtio_dev_allmulticast_disable,
+ .mtu_set = virtio_mtu_set,
.dev_infos_get = virtio_dev_info_get,
.stats_get = virtio_dev_stats_get,
.xstats_get = virtio_dev_xstats_get,
--
2.9.3.windows.1
next reply other threads:[~2016-09-16 17:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-16 17:13 souvikdey33 [this message]
2016-09-21 15:22 ` Kavanagh, Mark B
2016-09-22 13:56 ` [dpdk-dev] [PATCH v6] net/virtio: add set_mtu " Dey
2016-09-29 20:31 ` [dpdk-dev] [PATCH v7] " Dey
2016-10-01 14:08 ` Dey, Souvik
2016-10-04 23:18 ` Dey, Souvik
2016-10-05 8:15 ` Kavanagh, Mark B
2016-10-05 14:05 ` Dey, Souvik
2016-10-06 13:39 ` Dey, Souvik
2016-10-06 13:58 ` Kavanagh, Mark B
2016-10-06 22:29 ` Stephen Hemminger
2016-10-07 2:06 ` Dey, Souvik
2016-10-09 3:52 ` Yuanhan Liu
2016-10-10 10:49 ` Kavanagh, Mark B
2016-10-11 4:01 ` Yuanhan Liu
2016-10-11 8:12 ` Kavanagh, Mark B
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