Re: [PATCH net-next] net: mana: Add handler for sriov configure

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, May 08, 2026 at 03:04:06PM -0700, Haiyang Zhang wrote:
> From: Haiyang Zhang <haiyangz@microsoft.com>
> 
> Add callback function for the pci_driver, sriov_configure.
> 
> Also disable VF autoprobe when it runs as PF driver on bare metal,
> since the hardware side may not have the VF ready immediately.
> 
> Export pci_vf_drivers_autoprobe() so the driver can toggle the VF
> autoprobe flag.

Technically pci_vf_drivers_autoprobe() doesn't *toggle* the autoprobe
flag.  That would mean setting it to the opposite of its current
value.

Here I would say "so the driver can prevent autoprobing of the VFs",
which is the intent.

Out of curiosity, how do the VFs eventually get probed?  I guess
there's some other mechanism that tells you when they're ready, and
you manually use sysfs 'sriov_drivers_autoprobe' to enable probing,
then bind drivers to them via sysfs?

The prevention of autoprobing sounds like a critical part of this
change; might be worth saying something in the subject, because "add
sriov configure" doesn't include much information.

> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

I assume this would go via a net tree since that's where the bulk of
the changes are.

> ---
>  .../net/ethernet/microsoft/mana/gdma_main.c   | 20 +++++++++++++++++++
>  drivers/pci/iov.c                             |  1 +
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> index 3bc3fff55999..767f11d5b351 100644
> --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> @@ -2094,6 +2094,11 @@ static int mana_gd_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  
>  	gc->numa_node = dev_to_node(&pdev->dev);
>  	gc->is_pf = mana_is_pf(pdev->device);
> +
> +	/* Disable VF autoprobe on BM */
> +	if (gc->is_pf)
> +		pci_vf_drivers_autoprobe(pdev, false);
> +
>  	gc->bar0_va = bar0_va;
>  	gc->dev = &pdev->dev;
>  	xa_init(&gc->irq_contexts);
> @@ -2262,6 +2267,20 @@ static void mana_gd_shutdown(struct pci_dev *pdev)
>  	pci_disable_device(pdev);
>  }
>  
> +static int mana_sriov_configure(struct pci_dev *pdev, int numvfs)
> +{
> +	int err = 0;
> +
> +	dev_info(&pdev->dev, "Requested num VFs: %d\n", numvfs);
> +
> +	if (numvfs > 0)
> +		err = pci_enable_sriov(pdev, numvfs);
> +	else
> +		pci_disable_sriov(pdev);
> +
> +	return err ? err : numvfs;
> +}
> +
>  static const struct pci_device_id mana_id_table[] = {
>  	{ PCI_DEVICE(PCI_VENDOR_ID_MICROSOFT, MANA_PF_DEVICE_ID) },
>  	{ PCI_DEVICE(PCI_VENDOR_ID_MICROSOFT, MANA_VF_DEVICE_ID) },
> @@ -2276,6 +2295,7 @@ static struct pci_driver mana_driver = {
>  	.suspend	= mana_gd_suspend,
>  	.resume		= mana_gd_resume,
>  	.shutdown	= mana_gd_shutdown,
> +	.sriov_configure = mana_sriov_configure,
>  };
>  
>  static int __init mana_driver_init(void)
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index 91ac4e37ecb9..5a701f44b8fd 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -1127,6 +1127,7 @@ void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool auto_probe)
>  	if (dev->is_physfn)
>  		dev->sriov->drivers_autoprobe = auto_probe;
>  }
> +EXPORT_SYMBOL_GPL(pci_vf_drivers_autoprobe);
>  
>  /**
>   * pci_iov_bus_range - find bus range used by Virtual Function
> -- 
> 2.34.1
>