[dpdk-dev] [PATCH] net/tap: remove Linux version check

[Pascal Mazon]

Hi Raslan,

Your patch looks ok at first glance. However, I couldn't test it as it 
does not apply on a
fresh next-net branch. Can you send a v2 after rebase?

Thank you.

Pascal

On 07/10/2017 10:13 AM, Raslan Darawsheh wrote:
> Remove checks of Linux kernel version
> in order to support kernel with backported features.
>
> The expected behavior with a kernel that doesn't
> support flower and other bits is the following:
> 	-flow validate can return successfully.
> 	-flow create using the same rule fails.
>
> Using the  "remote" feature without kernel flower doesn not fail silently.
> The TAP instance is not initialized if the requested parameters cannot be satisfied.
>
> it has been tested on an old kernel without required support:
>
> PMD: Kernel refused TC filter rule creation (2): No such file or directory
> PMD: tap0 failed to create implicit rules.
> PMD: Can't set up remote feature: No such file of directory(2)
> PMD: TAP Unable to initialize net_tap0
>
> Signed-off-by: Raslan Darawsheh <rasland at mellanox.com>
> ---
>   drivers/net/tap/rte_eth_tap.c | 38 +-------------------------------------
>   drivers/net/tap/rte_eth_tap.h |  2 --
>   drivers/net/tap/tap_flow.c    | 13 +------------
>   3 files changed, 2 insertions(+), 51 deletions(-)
>
> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> index e54758e..b9e3ee9 100644
> --- a/drivers/net/tap/rte_eth_tap.c
> +++ b/drivers/net/tap/rte_eth_tap.c
> @@ -77,9 +77,6 @@
>   #define ETH_TAP_MAC_ARG         "mac"
>   #define ETH_TAP_MAC_FIXED       "fixed"
>   
> -#define FLOWER_KERNEL_VERSION KERNEL_VERSION(4, 2, 0)
> -#define FLOWER_VLAN_KERNEL_VERSION KERNEL_VERSION(4, 9, 0)
> -
>   static struct rte_vdev_driver pmd_tap_drv;
>   
>   static const char *valid_arguments[] = {
> @@ -1162,24 +1159,6 @@ static const struct eth_dev_ops ops = {
>   };
>   
>   static int
> -tap_kernel_support(struct pmd_internals *pmd)
> -{
> -	struct utsname utsname;
> -	int ver[3];
> -
> -	if (uname(&utsname) == -1 ||
> -	    sscanf(utsname.release, "%d.%d.%d",
> -		   &ver[0], &ver[1], &ver[2]) != 3)
> -		return 0;
> -	if (KERNEL_VERSION(ver[0], ver[1], ver[2]) >= FLOWER_KERNEL_VERSION)
> -		pmd->flower_support = 1;
> -	if (KERNEL_VERSION(ver[0], ver[1], ver[2]) >=
> -	    FLOWER_VLAN_KERNEL_VERSION)
> -		pmd->flower_vlan_support = 1;
> -	return 1;
> -}
> -
> -static int
>   eth_dev_tap_create(const char *name, char *tap_name, char *remote_iface,
>   		   int fixed_mac_type)
>   {
> @@ -1278,20 +1257,6 @@ eth_dev_tap_create(const char *name, char *tap_name, char *remote_iface,
>   	if (tap_ioctl(pmd, SIOCSIFHWADDR, &ifr, 0, LOCAL_ONLY) < 0)
>   		goto error_exit;
>   
> -	tap_kernel_support(pmd);
> -	if (!pmd->flower_support) {
> -		if (remote_iface[0]) {
> -			RTE_LOG(ERR, PMD,
> -				"%s: kernel does not support TC rules, required for remote feature.",
> -				pmd->name);
> -			goto error_exit;
> -		} else {
> -			RTE_LOG(INFO, PMD,
> -				"%s: kernel too old for Flow API support.\n",
> -				pmd->name);
> -			return 0;
> -		}
> -	}
>   
>   	LIST_INIT(&pmd->flows);
>   	LIST_INIT(&pmd->implicit_flows);
> @@ -1382,7 +1347,6 @@ eth_dev_tap_create(const char *name, char *tap_name, char *remote_iface,
>   		RTE_LOG(ERR, PMD, "Remote feature requires flow support.\n");
>   		goto error_exit;
>   	}
> -	pmd->flower_support = 0;
>   	return 0;
>   
>   error_remote:
> @@ -1546,7 +1510,7 @@ rte_pmd_tap_remove(const char *name)
>   		return 0;
>   
>   	internals = eth_dev->data->dev_private;
> -	if (internals->flower_support && internals->nlsk_fd) {
> +	if (internals->nlsk_fd) {
>   		tap_flow_flush(eth_dev, NULL);
>   		tap_flow_implicit_flush(internals, NULL);
>   		nl_final(internals->nlsk_fd);
> diff --git a/drivers/net/tap/rte_eth_tap.h b/drivers/net/tap/rte_eth_tap.h
> index 2f22b2d..55c0b3f 100644
> --- a/drivers/net/tap/rte_eth_tap.h
> +++ b/drivers/net/tap/rte_eth_tap.h
> @@ -88,8 +88,6 @@ struct pmd_internals {
>   	int ioctl_sock;                   /* socket for ioctl calls */
>   	int nlsk_fd;                      /* Netlink socket fd */
>   	int flow_isolate;                 /* 1 if flow isolation is enabled */
> -	int flower_support;               /* 1 if kernel supports, else 0 */
> -	int flower_vlan_support;          /* 1 if kernel supports, else 0 */
>   	LIST_HEAD(tap_flows, rte_flow) flows;        /* rte_flow rules */
>   	/* implicit rte_flow rules set when a remote device is active */
>   	LIST_HEAD(tap_implicit_flows, rte_flow) implicit_flows;
> diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
> index ebf4564..6ade186 100644
> --- a/drivers/net/tap/tap_flow.c
> +++ b/drivers/net/tap/tap_flow.c
> @@ -1042,16 +1042,13 @@ priv_flow_process(struct pmd_internals *pmd,
>   		if (err)
>   			goto exit_item_not_supported;
>   		if (flow && cur_item->convert) {
> -			if (!pmd->flower_vlan_support &&
> -			    cur_item->convert == tap_flow_create_vlan)
> -				goto exit_item_not_supported;
>   			err = cur_item->convert(items, &data);
>   			if (err)
>   				goto exit_item_not_supported;
>   		}
>   	}
>   	if (flow) {
> -		if (pmd->flower_vlan_support && data.vlan) {
> +		if (data.vlan) {
>   			nlattr_add16(&flow->msg.nh, TCA_FLOWER_KEY_ETH_TYPE,
>   				     htons(ETH_P_8021Q));
>   			nlattr_add16(&flow->msg.nh,
> @@ -1401,10 +1398,6 @@ tap_flow_isolate(struct rte_eth_dev *dev,
>   {
>   	struct pmd_internals *pmd = dev->data->dev_private;
>   
> -	if (!pmd->flower_support)
> -		return -rte_flow_error_set(
> -			error, ENOSYS, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
> -			"rte_flow isolate requires TC flower kernel support");
>   	if (set)
>   		pmd->flow_isolate = 1;
>   	else
> @@ -1650,10 +1643,6 @@ tap_dev_filter_ctrl(struct rte_eth_dev *dev,
>   		    enum rte_filter_op filter_op,
>   		    void *arg)
>   {
> -	struct pmd_internals *pmd = dev->data->dev_private;
> -
> -	if (!pmd->flower_support)
> -		return -ENOTSUP;
>   	switch (filter_type) {
>   	case RTE_ETH_FILTER_GENERIC:
>   		if (filter_op != RTE_ETH_FILTER_GET)