RE: [PATCH v5 3/8] net/gve: add support for device initialization

["Guo, Junfeng" <junfeng.guo@intel.com>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@amd.com>
> Sent: Thursday, October 20, 2022 05:01
> To: Li, Xiaoyun <xiaoyun.li@intel.com>; Guo, Junfeng
> <junfeng.guo@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>; Wu,
> Jingjing <jingjing.wu@intel.com>
> Cc: ferruh.yigit@xilinx.com; dev@dpdk.org; awogbemila@google.com;
> Richardson, Bruce <bruce.richardson@intel.com>; Lin, Xueqin
> <xueqin.lin@intel.com>; Wang, Haiyue <haiyue.wang@intel.com>
> Subject: Re: [PATCH v5 3/8] net/gve: add support for device initialization
> 
> On 10/19/2022 4:59 PM, Li, Xiaoyun wrote:
> 
> >
> > Hi
> >
> >> -----Original Message-----
> >> From: Ferruh Yigit <ferruh.yigit@amd.com>
> >> Sent: Wednesday, October 19, 2022 14:46
> >> To: Guo, Junfeng <junfeng.guo@intel.com>; Zhang, Qi Z
> >> <qi.z.zhang@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>
> >> Cc: ferruh.yigit@xilinx.com; dev@dpdk.org; Li, Xiaoyun
> >> <xiaoyun.li@intel.com>; awogbemila@google.com; Richardson, Bruce
> >> <bruce.richardson@intel.com>; Lin, Xueqin <xueqin.lin@intel.com>;
> Wang,
> >> Haiyue <haiyue.wang@intel.com>
> >> Subject: Re: [PATCH v5 3/8] net/gve: add support for device
> initialization
> >>
> >> On 10/10/2022 11:17 AM, Junfeng Guo wrote:
> >>>
> >>> Support device init and add following devops skeleton:
> >>>    - dev_configure
> >>>    - dev_start
> >>>    - dev_stop
> >>>    - dev_close
> >>>
> >>> Note that build system (including doc) is also added in this patch.
> >>>
> >>> Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> >>> Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
> >>> Signed-off-by: Junfeng Guo <junfeng.guo@intel.com>
> >>
> >> <...>
> >>
> >>> diff --git a/doc/guides/rel_notes/release_22_11.rst
> >>> b/doc/guides/rel_notes/release_22_11.rst
> >>> index fbb575255f..c1162ea1a4 100644
> >>> --- a/doc/guides/rel_notes/release_22_11.rst
> >>> +++ b/doc/guides/rel_notes/release_22_11.rst
> >>> @@ -200,6 +200,11 @@ New Features
> >>>      into single event containing ``rte_event_vector``
> >>>      whose event type is ``RTE_EVENT_TYPE_CRYPTODEV_VECTOR``.
> >>>
> >>> +* **Added GVE net PMD**
> >>> +
> >>> +  * Added the new ``gve`` net driver for Google Virtual Ethernet
> devices.
> >>> +  * See the :doc:`../nics/gve` NIC guide for more details on this new
> driver.
> >>> +
> >>>
> >>
> >> Can you please move the block amaong the other ethdev drivers, as
> >> alphabetically sorted?
> >>
> >> <...>
> >>
> >>> +static int
> >>> +gve_dev_init(struct rte_eth_dev *eth_dev) {
> >>> +       struct gve_priv *priv = eth_dev->data->dev_private;
> >>> +       int max_tx_queues, max_rx_queues;
> >>> +       struct rte_pci_device *pci_dev;
> >>> +       struct gve_registers *reg_bar;
> >>> +       rte_be32_t *db_bar;
> >>> +       int err;
> >>> +
> >>> +       eth_dev->dev_ops = &gve_eth_dev_ops;
> >>> +
> >>> +       if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> >>> +               return 0;
> >>> +
> >>> +       pci_dev = RTE_DEV_TO_PCI(eth_dev->device);
> >>> +
> >>> +       reg_bar = pci_dev->mem_resource[GVE_REG_BAR].addr;
> >>> +       if (!reg_bar) {
> >>> +               PMD_DRV_LOG(ERR, "Failed to map pci bar!");
> >>> +               return -ENOMEM;
> >>> +       }
> >>> +
> >>> +       db_bar = pci_dev->mem_resource[GVE_DB_BAR].addr;
> >>> +       if (!db_bar) {
> >>> +               PMD_DRV_LOG(ERR, "Failed to map doorbell bar!");
> >>> +               return -ENOMEM;
> >>> +       }
> >>> +
> >>> +       gve_write_version(&reg_bar->driver_version);
> >>> +       /* Get max queues to alloc etherdev */
> >>> +       max_tx_queues = ioread32be(&reg_bar->max_tx_queues);
> >>> +       max_rx_queues = ioread32be(&reg_bar->max_rx_queues);
> >>> +
> >>> +       priv->reg_bar0 = reg_bar;
> >>> +       priv->db_bar2 = db_bar;
> >>> +       priv->pci_dev = pci_dev;
> >>> +       priv->state_flags = 0x0;
> >>> +
> >>> +       priv->max_nb_txq = max_tx_queues;
> >>> +       priv->max_nb_rxq = max_rx_queues;
> >>> +
> >>> +       err = gve_init_priv(priv, false);
> >>> +       if (err)
> >>> +               return err;
> >>> +
> >>> +       eth_dev->data->mac_addrs = rte_zmalloc("gve_mac",
> sizeof(struct
> >> rte_ether_addr), 0);
> >>> +       if (!eth_dev->data->mac_addrs) {
> >>> +               PMD_DRV_LOG(ERR, "Failed to allocate memory to store
> mac
> >> address");
> >>> +               return -ENOMEM;
> >>> +       }
> >>> +       rte_ether_addr_copy(&priv->dev_addr,
> >>> + eth_dev->data->mac_addrs);
> >>> +
> >>
> >> Is anything assinged to 'priv->dev_addr' to copy?
> >> Also since there is a 'priv->dev_addr' field, why not use it directly,
> instead of
> >> allocating memory for 'eth_dev->data->mac_addrs'?
> >> I mean why not "eth_dev->data->mac_addrs = &priv->dev_addr"?
> >
> > Makes sense. There's no need to allocate a new memory. @Guo,
> Junfeng Can you update this?

Thanks Xiaoyun and Ferruh for the comments!
I tried to update the code as suggested but may get "Invalid Memory"
warning when quit the testpmd. I found it was caused at the function
rte_eth_dev_release_port with " rte_free(eth_dev->data->mac_addrs); ".
Seems that allocating memory for 'eth_dev->data->mac_addrs' is still
needed. Please help correct me if I misunderstood this. Thanks! I'll keep 
this part unchanged for the coming patchset first.

> >>
> >> <...>
> >>
> >>> +struct gve_priv {
> >>> +       struct gve_irq_db *irq_dbs; /* array of num_ntfy_blks */
> >>> +       const struct rte_memzone *irq_dbs_mz;
> >>> +       uint32_t mgmt_msix_idx;
> >>> +       rte_be32_t *cnt_array; /* array of num_event_counters */
> >>> +       const struct rte_memzone *cnt_array_mz;
> >>> +
> >>> +       uint16_t num_event_counters;
> >>> +       uint16_t tx_desc_cnt; /* txq size */
> >>> +       uint16_t rx_desc_cnt; /* rxq size */
> >>> +       uint16_t tx_pages_per_qpl; /* tx buffer length */
> >>> +       uint16_t rx_data_slot_cnt; /* rx buffer length */
> >>
> >> These fields are not used in this patch, I guess some will be used in
> datapath
> >> patch.
> >
> > This is needed for base code gve_adminq.c not for datapath. Most of
> the stuff in gve_priv is for gve_adminq.c.
> > The adminq will update this info which dpdk pmd will need later.
> Compiler will complain if these don't exsit.
> >
> 
> You are right they are used by 'gve_adminq.c', so OK to keep them, if
> there are ones not used at this stage, can you add them whenever they
> are used, or remove them if not used at all. If all used/required, no
> change required.

Yes, we have already tried to move all the unused items to the corresponding 
stages patch by patch. Thanks for reminding this!

> 
> >>
> >> Can you please only add fields that is used in the patch? This way it will
> be
> >> clear in which functionality that field is used and enable to detect not
> used
> >> fields.
> >> We are accepting batch updates for base code, but this is dpdk related
> code,
> >> lets only add things that are used when they are used.
> >> Same for all data structures.
> >>
> >> <...>
> >>
> >>> diff --git a/drivers/net/gve/version.map
> b/drivers/net/gve/version.map
> >>> new file mode 100644 index 0000000000..c2e0723b4c
> >>> --- /dev/null
> >>> +++ b/drivers/net/gve/version.map
> >>> @@ -0,0 +1,3 @@
> >>> +DPDK_22 {
> >>
> >> DPDK_23