Re: [dpdk-dev] [PATCH v2 09/44] net/virtio: move MSIX detection to PCI ethdev

["Xia, Chenbo" <chenbo.xia@intel.com>]

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, January 20, 2021 5:25 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; olivier.matz@6wind.com;
> amorenoz@redhat.com; david.marchand@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v2 09/44] net/virtio: move MSIX detection to PCI ethdev
> 
> This patch introduces a new callback to notify the bus
> driver some interrupt related operation was done.
> 
> This is used by Virtio PCI driver to check msix status.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_ethdev.c     |  12 +--
>  drivers/net/virtio/virtio_pci.c        | 120 ++++++++++++++-----------
>  drivers/net/virtio/virtio_pci.h        |   6 +-
>  drivers/net/virtio/virtio_pci_ethdev.c |   2 +
>  4 files changed, 82 insertions(+), 58 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c
> b/drivers/net/virtio/virtio_ethdev.c
> index a3e81f336d..13d5a76376 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -1287,8 +1287,8 @@ virtio_intr_unmask(struct rte_eth_dev *dev)
>  	if (rte_intr_ack(dev->intr_handle) < 0)
>  		return -1;
> 
> -	if (hw->bus_type == VIRTIO_BUS_PCI_LEGACY || hw->bus_type ==
> VIRTIO_BUS_PCI_MODERN)
> -		hw->use_msix = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));
> +	if (VTPCI_OPS(hw)->intr_event)

Emmm.. why is callback called intr_event? The callback detects/checks msix and lsc.
IMHO, maybe intr_detect? Or another similar verb you like 😊

> +		VTPCI_OPS(hw)->intr_event(hw);
> 
>  	return 0;

<snip>

> 
> +msix_detect:
> +	hw->use_msix = vtpci_msix_detect(dev);
> +

Just use use the callback introduced? Should also work later when intr_lsc is added.

Thanks,
Chenbo

>  	return 0;
>  }
> 
> -enum virtio_msix_status
> -vtpci_msix_detect(struct rte_pci_device *dev)
> -{
> -	uint8_t pos;
> -	int ret;
> -
> -	ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST);
> -	if (ret != 1) {
> -		PMD_INIT_LOG(DEBUG,
> -			     "failed to read pci capability list, ret %d", ret);
> -		return VIRTIO_MSIX_NONE;
> -	}
> -
> -	while (pos) {
> -		uint8_t cap[2];
> -
> -		ret = rte_pci_read_config(dev, cap, sizeof(cap), pos);
> -		if (ret != sizeof(cap)) {
> -			PMD_INIT_LOG(DEBUG,
> -				     "failed to read pci cap at pos: %x ret %d",
> -				     pos, ret);
> -			break;
> -		}
> -
> -		if (cap[0] == PCI_CAP_ID_MSIX) {
> -			uint16_t flags;
> -
> -			ret = rte_pci_read_config(dev, &flags, sizeof(flags),
> -					pos + sizeof(cap));
> -			if (ret != sizeof(flags)) {
> -				PMD_INIT_LOG(DEBUG,
> -					     "failed to read pci cap at pos:"
> -					     " %x ret %d", pos + 2, ret);
> -				break;
> -			}
> -
> -			if (flags & PCI_MSIX_ENABLE)
> -				return VIRTIO_MSIX_ENABLED;
> -			else
> -				return VIRTIO_MSIX_DISABLED;
> -		}
> -
> -		pos = cap[1];
> -	}
> -
> -	return VIRTIO_MSIX_NONE;
> -}
> diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
> index 59f6688218..6f5c53c4b7 100644
> --- a/drivers/net/virtio/virtio_pci.h
> +++ b/drivers/net/virtio/virtio_pci.h
> @@ -239,6 +239,7 @@ struct virtio_pci_ops {
>  	int (*setup_queue)(struct virtio_hw *hw, struct virtqueue *vq);
>  	void (*del_queue)(struct virtio_hw *hw, struct virtqueue *vq);
>  	void (*notify_queue)(struct virtio_hw *hw, struct virtqueue *vq);
> +	void (*intr_event)(struct virtio_hw *hw);
>  };
> 
>  struct virtio_net_config;
> @@ -303,10 +304,13 @@ struct virtio_pci_dev {
>  struct virtio_hw_internal {
>  	const struct virtio_pci_ops *vtpci_ops;
>  	struct rte_pci_ioport io;
> +	struct rte_pci_device *dev;
>  };
> 
>  #define VTPCI_OPS(hw)	(virtio_hw_internal[(hw)->port_id].vtpci_ops)
>  #define VTPCI_IO(hw)	(&virtio_hw_internal[(hw)->port_id].io)
> +#define VTPCI_DEV(hw)	(virtio_hw_internal[(hw)->port_id].dev)
> +
> 
>  extern struct virtio_hw_internal virtio_hw_internal[RTE_MAX_ETHPORTS];
> 
> @@ -383,8 +387,6 @@ void vtpci_read_dev_config(struct virtio_hw *, size_t,
> void *, int);
> 
>  uint8_t vtpci_isr(struct virtio_hw *);
> 
> -enum virtio_msix_status vtpci_msix_detect(struct rte_pci_device *dev);
> -
>  extern const struct virtio_pci_ops legacy_ops;
>  extern const struct virtio_pci_ops modern_ops;
>  extern const struct virtio_pci_ops virtio_user_ops;
> diff --git a/drivers/net/virtio/virtio_pci_ethdev.c
> b/drivers/net/virtio/virtio_pci_ethdev.c
> index 6a0ef6edc3..045b134ef2 100644
> --- a/drivers/net/virtio/virtio_pci_ethdev.c
> +++ b/drivers/net/virtio/virtio_pci_ethdev.c
> @@ -73,6 +73,8 @@ eth_virtio_pci_init(struct rte_eth_dev *eth_dev)
>  	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(eth_dev);
>  	int ret;
> 
> +	VTPCI_DEV(hw) = pci_dev;
> +
>  	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
>  		ret = vtpci_init(RTE_ETH_DEV_TO_PCI(eth_dev), hw);
>  		if (ret) {
> --
> 2.29.2