[dpdk-dev] [RFC] ethdev: configure SR-IOV VF from host
Iremonger, Bernard
bernard.iremonger at intel.com
Thu Aug 29 17:02:11 CEST 2019
Hi Thomas,
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas at monjalon.net]
> Sent: Thursday, August 15, 2019 4:06 PM
> To: Yigit, Ferruh <ferruh.yigit at intel.com>; Andrew Rybchenko
> <arybchenko at solarflare.com>
> Cc: dev at dpdk.org; Iremonger, Bernard <bernard.iremonger at intel.com>;
> Shahaf Shuler <shahafs at mellanox.com>; E. Scott Daniels
> <daniels at research.att.com>; Lu, Wenzhuo <wenzhuo.lu at intel.com>; Alex
> Zelezniak <alexz at att.com>; Ajit Khaparde <ajit.khaparde at broadcom.com>;
> Doherty, Declan <declan.doherty at intel.com>
> Subject: [RFC] ethdev: configure SR-IOV VF from host
>
> In a virtual environment, the network controller may have to configure some
> SR-IOV VF parameters for security reasons.
>
> When the PF (host port) is drived by DPDK (OVS-DPDK case), we face two
> different cases:
> - driver is bifurcated (Mellanox case),
> so the VF can be configured via the kernel.
> - driver is on top of UIO or VFIO, so DPDK API is required.
>
> This RFC proposes to use generic DPDK API for VF configuration.
> The impacted functions are (can be extended):
>
> - rte_eth_dev_is_valid_port
> - rte_eth_promiscuous_enable
> - rte_eth_promiscuous_disable
> - rte_eth_promiscuous_get
> - rte_eth_allmulticast_enable
> - rte_eth_allmulticast_disable
> - rte_eth_allmulticast_get
> - rte_eth_dev_set_mc_addr_list
> - rte_eth_dev_default_mac_addr_set
> - rte_eth_macaddr_get
> - rte_eth_dev_mac_addr_add
> - rte_eth_dev_mac_addr_remove
> - rte_eth_dev_vlan_filter
> - rte_eth_dev_get_mtu
> - rte_eth_dev_set_mtu
>
> In order to target these functions to a VF (which has no port id in the host),
> the higher bit of port id is reserved:
>
> #define RTE_ETH_VF_PORT_FLAG (1 << 15)
>
> This bit can be combined only with the port id of a representor.
> The meaning is to target the VF connected with the representor port, instead
> of the representor port itself.
>
> If a function is not expected to support VF configuration, it will return -
> EINVAL, i.e. there is no code change.
> If an API function (listed above) can support VF configuration, but the PMD
> does not support it, then -ENOTSUP must be returned.
>
> As an example, this is the change required in rte_eth_dev_is_valid_port:
>
> int
> rte_eth_dev_is_valid_port(uint16_t port_id) {
> + uint32_t dev_flags;
> + uint16_t vf_flag;
> +
> + vf_flag = port_id & RTE_ETH_VF_PORT_FLAG;
> + port_id &= RTE_ETH_VF_PORT_FLAG - 1; /* remove VF flag */
> +
> if (port_id >= RTE_MAX_ETHPORTS ||
> (rte_eth_devices[port_id].state == RTE_ETH_DEV_UNUSED))
> return 0;
> - else
> - return 1;
> +
> + dev_flags = rte_eth_dev_shared_data->data[port_id].dev_flags;
> + if (vf_flag != 0 && (dev_flags & RTE_ETH_DEV_REPRESENTOR) == 0)
> + return 0; /* VF flag has no meaning if not a representor
> + */
> +
> + return 1;
> }
>
>
Some of the functions in the list above for example, rte_eth_dev_promiscuous_enable() use the dev_ops structure, is it intended to add more rte_eth_dev_* functions to the dev_ops structure?
At present the ixgbe and i40e PMD's have sets of private functions for configuring SRIOV VF's from the DPDK PF, rte_pmd_ixgbe_* and rte_pmd_i40e_* functions (see rte_pmd_ixgbe.h and rte_pmd_i40e.h).
At the time these functions were not allowed to be added to the dev_ops structure as there were so many of them. There was a proposal to add a dev_ctrl function to the dev_ops structure which would access the private functions. Maybe adding the dev_ctrl function should be considered again.
Having two ways (through dev_ops and private PMD functions) to configure DPDK VF's from the DPDK PF will be confusing for developers.
Regards,
Bernard.
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