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

["Xia, Chenbo" <chenbo.xia@intel.com>]

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Thursday, May 5, 2022 6:27 PM
> To: dev@dpdk.org; jasowang@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>;
> david.marchand@redhat.com; olivier.matz@6wind.com
> Cc: stable@dpdk.org; Maxime Coquelin <maxime.coquelin@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.coquelin@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
> 
>  static const char *valid_arguments[] = {
> @@ -1563,6 +1564,7 @@ rte_pmd_vhost_probe(struct rte_vdev_device *dev)
>  	int tso = 0;
>  	int linear_buf = 0;
>  	int ext_buf = 0;
> +	int legacy_ol_flags = 0;
>  	struct rte_eth_dev *eth_dev;
>  	const char *name = rte_vdev_device_name(dev);
> 
> @@ -1672,6 +1674,17 @@ rte_pmd_vhost_probe(struct rte_vdev_device *dev)
>  			flags |= RTE_VHOST_USER_EXTBUF_SUPPORT;
>  	}
> 
> +	if (rte_kvargs_count(kvlist, ETH_VHOST_LEGACY_OL_FLAGS) == 1) {
> +		ret = rte_kvargs_process(kvlist,
> +				ETH_VHOST_LEGACY_OL_FLAGS,
> +				&open_int, &legacy_ol_flags);
> +		if (ret < 0)
> +			goto out_free;
> +	}
> +
> +	if (legacy_ol_flags == 0)
> +		flags |= RTE_VHOST_USER_NET_COMPLIANT_OL_FLAGS;

Putting this check into above '{}' like other option does, will look better.

Thanks,
Chenbo

> +
>  	if (dev->device.numa_node == SOCKET_ID_ANY)
>  		dev->device.numa_node = rte_socket_id();
> 
> --
> 2.35.1