Re: [PATCH 3/6] net/vhost: enable compliant offloading mode

[Maxime Coquelin]

Hi Wenwu,

On 6/7/22 03:19, Ma, WenwuX wrote:

Hi Maxime,

-----Original Message-----
From: Xia, Chenbo <chenbo....@intel.com>
Sent: 2022年5月16日 21:40
To: Maxime Coquelin <maxime.coque...@redhat.com>; dev@dpdk.org;
jasow...@redhat.com; david.march...@redhat.com;
olivier.m...@6wind.com
Cc: sta...@dpdk.org
Subject: RE: [PATCH 3/6] net/vhost: enable compliant offloading mode

-----Original Message-----
From: Maxime Coquelin <maxime.coque...@redhat.com>
Sent: Monday, May 16, 2022 9:29 PM
To: Xia, Chenbo <chenbo....@intel.com>; dev@dpdk.org;
jasow...@redhat.com; david.march...@redhat.com;

olivier.m...@6wind.com

Cc: sta...@dpdk.org
Subject: Re: [PATCH 3/6] net/vhost: enable compliant offloading mode

Hi Chenbo,

On 5/16/22 15:26, Xia, Chenbo wrote:

Hi Maxime,

-----Original Message-----
From: Maxime Coquelin <maxime.coque...@redhat.com>
Sent: Thursday, May 5, 2022 6:27 PM
To: dev@dpdk.org; jasow...@redhat.com; Xia, Chenbo

<chenbo....@intel.com>;

david.march...@redhat.com; olivier.m...@6wind.com
Cc: sta...@dpdk.org; Maxime Coquelin <maxime.coque...@redhat.com>
Subject: [PATCH 3/6] net/vhost: enable compliant offloading mode

This patch enables the compliant offloading flags mode by default,
which prevents the Rx path to set Tx offload flags, which is
illegal. A new legacy-ol-flags devarg is introduced to enable the
legacy behaviour.

Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
   doc/guides/nics/vhost.rst         |  6 ++++++
   drivers/net/vhost/rte_eth_vhost.c | 19 ++++++++++++++++---
   2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/doc/guides/nics/vhost.rst b/doc/guides/nics/vhost.rst
index ee802ec4a8..d7c0e2ade8 100644
--- a/doc/guides/nics/vhost.rst
+++ b/doc/guides/nics/vhost.rst
@@ -64,6 +64,12 @@ The user can specify below arguments in `--vdev`

option.

       It is used to enable external buffer support in vhost library.
       (Default: 0 (disabled))

+#.  ``legacy-ol-flags``:
+
+    It is used to restore legacy behavior for offloading that was not
+    compliant with offloading API.
+    (Default: 0 (disabled))
+
   Vhost PMD event handling
   ------------------------

diff --git a/drivers/net/vhost/rte_eth_vhost.c
b/drivers/net/vhost/rte_eth_vhost.c
index 070f0e6dfd..0a2e8d9b29 100644
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -31,9 +31,10 @@ enum {VIRTIO_RXQ, VIRTIO_TXQ,

VIRTIO_QNUM};

   #define ETH_VHOST_CLIENT_ARG         "client"
   #define ETH_VHOST_IOMMU_SUPPORT              "iommu-support"
   #define ETH_VHOST_POSTCOPY_SUPPORT   "postcopy-support"
-#define ETH_VHOST_VIRTIO_NET_F_HOST_TSO "tso"
-#define ETH_VHOST_LINEAR_BUF  "linear-buffer"
-#define ETH_VHOST_EXT_BUF  "ext-buffer"
+#define ETH_VHOST_VIRTIO_NET_F_HOST_TSO        "tso"
+#define ETH_VHOST_LINEAR_BUF           "linear-buffer"
+#define ETH_VHOST_EXT_BUF              "ext-buffer"
+#define ETH_VHOST_LEGACY_OL_FLAGS      "legacy-ol-flags"
   #define VHOST_MAX_PKT_BURST 32

ETH_VHOST_LEGACY_OL_FLAGS should be added into valid_arguments array.

static const char *valid_arguments[] = {
         ETH_VHOST_IFACE_ARG,
         ETH_VHOST_QUEUES_ARG,
         ETH_VHOST_CLIENT_ARG,
         ETH_VHOST_IOMMU_SUPPORT,
         ETH_VHOST_POSTCOPY_SUPPORT,
         ETH_VHOST_VIRTIO_NET_F_HOST_TSO,
         ETH_VHOST_LINEAR_BUF,
         ETH_VHOST_EXT_BUF,
         NULL
};

Thanks, good catch!
I missed to test this new devarg addition, fixing it for v2.

Maxime