[dpdk-dev] [PATCH v2 04/24] virtio: Add support for Link State interrupt

[Xie, Huawei]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Ouyang Changchun
> Sent: Tuesday, January 27, 2015 10:36 AM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH v2 04/24] virtio: Add support for Link State interrupt
> 
> Virtio has link state interrupt which can be used.
> 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> Signed-off-by: Changchun Ouyang <changchun.ouyang at intel.com>
> ---
>  lib/librte_pmd_virtio/virtio_ethdev.c | 78 +++++++++++++++++++++++++++------
> --
>  lib/librte_pmd_virtio/virtio_pci.c    | 22 ++++++++++
>  lib/librte_pmd_virtio/virtio_pci.h    |  4 ++
>  3 files changed, 86 insertions(+), 18 deletions(-)
> 
> diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c
> b/lib/librte_pmd_virtio/virtio_ethdev.c
> index 5df3b54..ef87ff8 100644
> --- a/lib/librte_pmd_virtio/virtio_ethdev.c
> +++ b/lib/librte_pmd_virtio/virtio_ethdev.c
> @@ -845,6 +845,34 @@ static int virtio_resource_init(struct rte_pci_device
> *pci_dev __rte_unused)
>  #endif
> 
>  /*
> + * Process Virtio Config changed interrupt and call the callback
> + * if link state changed.
> + */
> +static void
> +virtio_interrupt_handler(__rte_unused struct rte_intr_handle *handle,
> +			 void *param)
> +{
> +	struct rte_eth_dev *dev = param;
> +	struct virtio_hw *hw =
> +		VIRTIO_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> +	uint8_t isr;
> +
> +	/* Read interrupt status which clears interrupt */
> +	isr = vtpci_isr(hw);
> +	PMD_DRV_LOG(INFO, "interrupt status = %#x", isr);
> +
> +	if (rte_intr_enable(&dev->pci_dev->intr_handle) < 0)
> +		PMD_DRV_LOG(ERR, "interrupt enable failed");
> +

Is it better to put rte_intr_enable after we have handled the interrupt.
Is there the possibility of interrupt reentrant in uio intr framework?

> +	if (isr & VIRTIO_PCI_ISR_CONFIG) {
> +		if (virtio_dev_link_update(dev, 0) == 0)
> +			_rte_eth_dev_callback_process(dev,
> +
> RTE_ETH_EVENT_INTR_LSC);
> +	}
> +
> +}
> +
>