Re: [PATCH 2/3] net/vmxnet3: fix vmxnet3 dev_uninit() hot-unplug

[Luca Boccassi <bluca@debian.org>]

Hi,

The application must already stop and close before detaching (which
will call uninit). Quoting from the documentation:

"*  Before detaching, they must be stopped and closed.

    DPDK applications must call "rte_eth_dev_stop()" and
    "rte_eth_dev_close()" APIs before detaching ports. These functions will
    start finalization sequence of the PMDs."

http://doc.dpdk.org/guides/prog_guide/port_hotplug_framework.html

On Mon, 2018-09-17 at 19:06 +0000, Louis Luo wrote:
> Hi Luca,
> 
> When eth_vmxnet3_dev_uninit() is called, is it guaranteed that
> vmxnet3_dev_close/ vmxnet3_dev_stop must have been called? I'm not
> familiar with the hot-plug procedure, so just wonder if there is any
> chance that eth_vmxnet3_dev_uninit() is called without calling
> vmxnet3_dev_close/ vmxnet3_dev_stop.
> 
> Thanks,
> Louis
> 
> On 8/16/18, 6:51 AM, "dev on behalf of Luca Boccassi" <dev-bounces@d
> pdk.org on behalf of bluca@debian.org> wrote:
> 
>     The vmxnet3 driver can't call back into dev_close(), and possibly
>     dev_stop(), in dev_uninit().  When dev_uninit() is called,
> anything
>     that those routines would want to clean up has already been
> released.
>     Further, for complete cleanup, it is necessary to release any of
> the
>     queue resources during dev_close().
>     This allows a vmxnet3 device to be hot-unplugged without leaking
>     queues.
>     
>     Fixes: dfaff37fc46d ("vmxnet3: import new vmxnet3 poll mode
> driver implementation")
>     Cc: stable@dpdk.org
>     
>     Signed-off-by: Brian Russell <brussell@brocade.com>
>     Signed-off-by: Luca Boccassi <bluca@debian.org>
>     ---
>      drivers/net/vmxnet3/vmxnet3_ethdev.c | 36 ++++++++++++++++++++
> --------
>      1 file changed, 26 insertions(+), 10 deletions(-)
>     
>     diff --git a/drivers/net/vmxnet3/vmxnet3_ethdev.c
> b/drivers/net/vmxnet3/vmxnet3_ethdev.c
>     index 2613cd1358..b5d4be5e24 100644
>     --- a/drivers/net/vmxnet3/vmxnet3_ethdev.c
>     +++ b/drivers/net/vmxnet3/vmxnet3_ethdev.c
>     @@ -348,16 +348,11 @@ eth_vmxnet3_dev_init(struct rte_eth_dev
> *eth_dev)
>      static int
>      eth_vmxnet3_dev_uninit(struct rte_eth_dev *eth_dev)
>      {
>     -	struct vmxnet3_hw *hw = eth_dev->data->dev_private;
>     -
>      	PMD_INIT_FUNC_TRACE();
>      
>      	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
>      		return 0;
>      
>     -	if (hw->adapter_stopped == 0)
>     -		vmxnet3_dev_close(eth_dev);
>     -
>      	eth_dev->dev_ops = NULL;
>      	eth_dev->rx_pkt_burst = NULL;
>      	eth_dev->tx_pkt_burst = NULL;
>     @@ -803,7 +798,7 @@ vmxnet3_dev_stop(struct rte_eth_dev *dev)
>      	PMD_INIT_FUNC_TRACE();
>      
>      	if (hw->adapter_stopped == 1) {
>     -		PMD_INIT_LOG(DEBUG, "Device already closed.");
>     +		PMD_INIT_LOG(DEBUG, "Device already stopped.");
>      		return;
>      	}
>      
>     @@ -827,7 +822,6 @@ vmxnet3_dev_stop(struct rte_eth_dev *dev)
>      	/* reset the device */
>      	VMXNET3_WRITE_BAR1_REG(hw, VMXNET3_REG_CMD,
> VMXNET3_CMD_RESET_DEV);
>      	PMD_INIT_LOG(DEBUG, "Device reset.");
>     -	hw->adapter_stopped = 0;
>      
>      	vmxnet3_dev_clear_queues(dev);
>      
>     @@ -837,6 +831,30 @@ vmxnet3_dev_stop(struct rte_eth_dev *dev)
>      	link.link_speed = ETH_SPEED_NUM_10G;
>      	link.link_autoneg = ETH_LINK_FIXED;
>      	rte_eth_linkstatus_set(dev, &link);
>     +
>     +	hw->adapter_stopped = 1;
>     +}
>     +
>     +static void
>     +vmxnet3_free_queues(struct rte_eth_dev *dev)
>     +{
>     +	int i;
>     +
>     +	PMD_INIT_FUNC_TRACE();
>     +
>     +	for (i = 0; i < dev->data->nb_rx_queues; i++) {
>     +		void *rxq = dev->data->rx_queues[i];
>     +
>     +		vmxnet3_dev_rx_queue_release(rxq);
>     +	}
>     +	dev->data->nb_rx_queues = 0;
>     +
>     +	for (i = 0; i < dev->data->nb_tx_queues; i++) {
>     +		void *txq = dev->data->tx_queues[i];
>     +
>     +		vmxnet3_dev_tx_queue_release(txq);
>     +	}
>     +	dev->data->nb_tx_queues = 0;
>      }
>      
>      /*
>     @@ -845,12 +863,10 @@ vmxnet3_dev_stop(struct rte_eth_dev *dev)
>      static void
>      vmxnet3_dev_close(struct rte_eth_dev *dev)
>      {
>     -	struct vmxnet3_hw *hw = dev->data->dev_private;
>     -
>      	PMD_INIT_FUNC_TRACE();
>      
>      	vmxnet3_dev_stop(dev);
>     -	hw->adapter_stopped = 1;
>     +	vmxnet3_free_queues(dev);
>      }
>      
>      static void
>     -- 
>     2.18.0
>     
>     
> 

-- 
Kind regards,
Luca Boccassi