[dpdk-dev] [PATCH v4] net/virtio: fix rxq intr config fails using vfio-pci

[Tan, Jianfeng]

> -----Original Message-----
> From: Yang, Zhiyong
> Sent: Thursday, November 9, 2017 12:46 PM
> To: dev at dpdk.org
> Cc: stable at dpdk.org; Tan, Jianfeng; yliu at fridaylinux.org;
> maxime.coquelin at redhat.com; Yang, Zhiyong
> Subject: [PATCH v4] net/virtio: fix rxq intr config fails using vfio-pci
> 
> When running l3fwd-power to test virtio rxq interrupt using vfio
> pci noiommu mode, startup fails. In the function virtio_read_caps,
> the code if (flags & PCI_MSIX_ENABLE) intends to double check
> if vfio msix is enabled or not. However, it is not enable at that
> time. So use_msix is assigned to "0", not "1", which causes the
> failure of configuring rxq intr in l3fwd-power.
> This patch adds the function "vtpci_msix_detect" to detect the status
> of msix when interrupt changes happen.
> In the meanwhile, virtio_intr_enable/disable are introduced to wrap
> rte_intr_enable/disable to enhance the ability to detect msix.
> use_msix can indicate three different msix status by:
> VIRTIO_MSIX_NONE (0)
> VIRTIO_MSIX_DISABLED (1)
> VIRTIO_MSIX_ENABLED (2)
> 
> CC: stable at dpdk.org
> CC: jianfeng.tan at intel.com
> CC: yliu at fridaylinux.org
> CC: maxime.coquelin at redhat.com
> 
> Fixes: cb482cb3a305 ("net/virtio: fix MAC address read")
> Signed-off-by: Zhiyong Yang <zhiyong.yang at intel.com>

Except a small nit, looks good to me:

Acked-by: Jianfeng Tan <jianfeng.tan at intel.com>

> ---
> 
> Changes in v4:
> Enhance the commit log description.
> 
> Changes in v3:
> Simply the code according to jianfeng's comments.
> 
> Changes in v2:
> Add the capability to detect msix if virtio intr changes.
> 
>  drivers/net/virtio/virtio_ethdev.c | 46
> ++++++++++++++++++++++++++++++------
>  drivers/net/virtio/virtio_pci.c    | 48
> ++++++++++++++++++++++++++++++++++++--
>  drivers/net/virtio/virtio_pci.h    |  6 +++++
>  3 files changed, 91 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c
> b/drivers/net/virtio/virtio_ethdev.c
> index d2576d5e0..87ac2bee6 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -97,6 +97,9 @@ static void virtio_mac_addr_remove(struct rte_eth_dev
> *dev, uint32_t index);
>  static void virtio_mac_addr_set(struct rte_eth_dev *dev,
>  				struct ether_addr *mac_addr);
> 
> +static int virtio_intr_enable(struct rte_eth_dev *dev);
> +static int virtio_intr_disable(struct rte_eth_dev *dev);
> +
>  static int virtio_dev_queue_stats_mapping_set(
>  	struct rte_eth_dev *eth_dev,
>  	uint16_t queue_id,
> @@ -618,7 +621,7 @@ virtio_dev_close(struct rte_eth_dev *dev)
>  		virtio_queues_unbind_intr(dev);
> 
>  	if (intr_conf->lsc || intr_conf->rxq) {
> -		rte_intr_disable(dev->intr_handle);
> +		virtio_intr_disable(dev);
>  		rte_intr_efd_disable(dev->intr_handle);
>  		rte_free(dev->intr_handle->intr_vec);
>  		dev->intr_handle->intr_vec = NULL;
> @@ -1160,6 +1163,34 @@ virtio_vlan_filter_set(struct rte_eth_dev *dev,
> uint16_t vlan_id, int on)
>  }
> 
>  static int
> +virtio_intr_enable(struct rte_eth_dev *dev)
> +{
> +	struct virtio_hw *hw = dev->data->dev_private;
> +
> +	if (rte_intr_enable(dev->intr_handle) < 0)
> +		return -1;
> +
> +	if (!hw->virtio_user_dev)
> +		hw->use_msix =
> vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));
> +
> +	return 0;
> +}
> +
> +static int
> +virtio_intr_disable(struct rte_eth_dev *dev)
> +{
> +	struct virtio_hw *hw = dev->data->dev_private;
> +
> +	if (rte_intr_disable(dev->intr_handle) < 0)
> +		return -1;
> +
> +	if (!hw->virtio_user_dev)
> +		hw->use_msix =
> vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));
> +
> +	return 0;
> +}
> +
> +static int
>  virtio_negotiate_features(struct virtio_hw *hw, uint64_t req_features)
>  {
>  	uint64_t host_features;
> @@ -1228,7 +1259,7 @@ virtio_interrupt_handler(void *param)
>  	isr = vtpci_isr(hw);
>  	PMD_DRV_LOG(INFO, "interrupt status = %#x", isr);
> 
> -	if (rte_intr_enable(dev->intr_handle) < 0)
> +	if (virtio_intr_enable(dev) < 0)
>  		PMD_DRV_LOG(ERR, "interrupt enable failed");
> 
>  	if (isr & VIRTIO_PCI_ISR_CONFIG) {
> @@ -1348,7 +1379,7 @@ virtio_configure_intr(struct rte_eth_dev *dev)
>  	 * to change the config size from 20 to 24, or
> VIRTIO_MSI_QUEUE_VECTOR
>  	 * (22) will be ignored.
>  	 */
> -	if (rte_intr_enable(dev->intr_handle) < 0) {
> +	if (virtio_intr_enable(dev) < 0) {
>  		PMD_DRV_LOG(ERR, "interrupt enable failed");
>  		return -1;
>  	}
> @@ -1388,7 +1419,8 @@ virtio_init_device(struct rte_eth_dev *eth_dev,
> uint64_t req_features)
>  	}
> 
>  	/* If host does not support both status and MSI-X then disable LSC */
> -	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) && hw-
> >use_msix)
> +	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) &&
> +	    hw->use_msix != VIRTIO_MSIX_NONE)
>  		eth_dev->data->dev_flags |= RTE_ETH_DEV_INTR_LSC;
>  	else
>  		eth_dev->data->dev_flags &= ~RTE_ETH_DEV_INTR_LSC;
> @@ -1801,9 +1833,9 @@ virtio_dev_start(struct rte_eth_dev *dev)
>  	 */
>  	if (dev->data->dev_conf.intr_conf.lsc ||
>  	    dev->data->dev_conf.intr_conf.rxq) {
> -		rte_intr_disable(dev->intr_handle);
> +		virtio_intr_disable(dev);
> 
> -		if (rte_intr_enable(dev->intr_handle) < 0) {
> +		if (virtio_intr_enable(dev) < 0) {
>  			PMD_DRV_LOG(ERR, "interrupt enable failed");
>  			return -EIO;
>  		}
> @@ -1912,7 +1944,7 @@ virtio_dev_stop(struct rte_eth_dev *dev)
>  	PMD_INIT_LOG(DEBUG, "stop");
> 
>  	if (intr_conf->lsc || intr_conf->rxq)
> -		rte_intr_disable(dev->intr_handle);
> +		virtio_intr_disable(dev);
> 
>  	hw->started = 0;
>  	memset(&link, 0, sizeof(link));
> diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
> index 55b717c03..10c45228c 100644
> --- a/drivers/net/virtio/virtio_pci.c
> +++ b/drivers/net/virtio/virtio_pci.c
> @@ -57,7 +57,8 @@
>   * The remaining space is defined by each driver as the per-driver
>   * configuration space.
>   */
> -#define VIRTIO_PCI_CONFIG(hw) (((hw)->use_msix) ? 24 : 20)
> +#define VIRTIO_PCI_CONFIG(hw) \
> +		(((hw)->use_msix == VIRTIO_MSIX_ENABLED) ? 24 : 20)
> 
>  static inline int
>  check_vq_phys_addr_ok(struct virtqueue *vq)
> @@ -617,7 +618,9 @@ virtio_read_caps(struct rte_pci_device *dev, struct
> virtio_hw *hw)
>  			uint16_t flags = ((uint16_t *)&cap)[1];
> 
>  			if (flags & PCI_MSIX_ENABLE)
> -				hw->use_msix = 1;
> +				hw->use_msix = VIRTIO_MSIX_ENABLED;
> +			else
> +				hw->use_msix = VIRTIO_MSIX_DISABLED;
>  		}
> 
>  		if (cap.cap_vndr != PCI_CAP_ID_VNDR) {
> @@ -710,3 +713,44 @@ vtpci_init(struct rte_pci_device *dev, struct
> virtio_hw *hw)
> 
>  	return 0;
>  }
> +
> +/* Return 0 (VIRTIO_MSIX_NONE)
> + * Return 1 (VIRTIO_MSIX_DISABLED)
> + * Return 2 (VIRTIO_MSIX_ENABLED)
> + */

Above comments seems not necessary as it just repeat it's just the macro's definition.

Thanks,
Jianfeng