[07/40] net/virtio: move MSIX detection to PCI ethdev

  There is no point it detecting whether we can use MSIX
every time the interrupt is enabled/disabled/masked.

Let's do it once for all at PCI device init time.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/net/virtio/virtio_ethdev.c | 15 ---------------
 drivers/net/virtio/virtio_pci.c    |  5 ++++-
 2 files changed, 4 insertions(+), 16 deletions(-)
  

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Monday, December 21, 2020 5:14 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 07/40] net/virtio: move MSIX detection to PCI ethdev
> 
> There is no point it detecting whether we can use MSIX
> every time the interrupt is enabled/disabled/masked.
> 
> Let's do it once for all at PCI device init time.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_ethdev.c | 15 ---------------
>  drivers/net/virtio/virtio_pci.c    |  5 ++++-
>  2 files changed, 4 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c
> b/drivers/net/virtio/virtio_ethdev.c
> index 4032a89396..67f6be3fa8 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -1282,42 +1282,27 @@ virtio_vlan_filter_set(struct rte_eth_dev *dev,
> uint16_t vlan_id, int on)
>  static int
>  virtio_intr_unmask(struct rte_eth_dev *dev)
>  {
> -	struct virtio_hw *hw = dev->data->dev_private;
> -
>  	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));
> -
>  	return 0;
>  }
> 
>  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->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));
> -
>  	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->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));
> -
>  	return 0;
>  }
> 
> diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
> index 1692268f30..8605254e53 100644
> --- a/drivers/net/virtio/virtio_pci.c
> +++ b/drivers/net/virtio/virtio_pci.c
> @@ -698,7 +698,7 @@ vtpci_init(struct rte_pci_device *dev, struct virtio_hw
> *hw)
>  		PMD_INIT_LOG(INFO, "modern virtio pci detected.");
>  		virtio_hw_internal[hw->port_id].vtpci_ops = &modern_ops;
>  		hw->bus_type = VIRTIO_BUS_PCI_MODERN;
> -		return 0;
> +		goto msix_detect;
>  	}
> 
>  	PMD_INIT_LOG(INFO, "trying with legacy virtio pci.");
> @@ -718,6 +718,9 @@ vtpci_init(struct rte_pci_device *dev, struct virtio_hw
> *hw)
>  	virtio_hw_internal[hw->port_id].vtpci_ops = &legacy_ops;
>  	hw->bus_type = VIRTIO_BUS_PCI_LEGACY;
> 
> +msix_detect:
> +	hw->use_msix = vtpci_msix_detect(dev);
> +
>  	return 0;
>  }
> 
> --
> 2.29.2

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
  

On Sun, Dec 20, 2020 at 10:14 PM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> There is no point it detecting whether we can use MSIX
> every time the interrupt is enabled/disabled/masked.
>
> Let's do it once for all at PCI device init time.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Is this a rework/fix of fe19d49cb525 ("net/virtio: fix Rx interrupt
with VFIO") ?
  

On 1/6/21 9:22 AM, David Marchand wrote:
> On Sun, Dec 20, 2020 at 10:14 PM Maxime Coquelin
> <maxime.coquelin@redhat.com> wrote:
>>
>> There is no point it detecting whether we can use MSIX
>> every time the interrupt is enabled/disabled/masked.
>>
>> Let's do it once for all at PCI device init time.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> Is this a rework/fix of fe19d49cb525 ("net/virtio: fix Rx interrupt
> with VFIO") ?

Hmm, that was only planned as a rework, but it is likely to introduce a
regression by reverting the fix you mention.

I think I'll have to introduce a new callback so that drivers can update
their status.

Good catch, thanks!
Maxime