Subject: Re: [PATCH net-next] igb: Change how we check for pre-existing and assigned VFs

From: Greg Rose <[email-masked]>
Date: Wed, 15 Aug 2012 09:03:21 -0700

On Wed, 15 Aug 2012 07:51:26 +0200
Stefan Assmann <[email-masked]> wrote:

> Adapt the pre-existing and assigned VFs code to the ixgbe way
> introduced in commit 9297127b9cdd8d30c829ef5fd28b7cc0323a7bcd.
> 
> Instead of searching the enabled VFs we use pci_num_vf to determine
> enabled VFs. By comparing to which PF an assigned VF is owned it's
> possible to decide whether to leave it enabled or not.
> 
> Signed-off-by: Stefan Assmann <[email-masked]>

Acked-by: Greg Rose <[email-masked]>

> ---
>  drivers/net/ethernet/intel/igb/igb.h      |    1 -
>  drivers/net/ethernet/intel/igb/igb_main.c |  104
> ++++++----------------------- 2 files changed, 22 insertions(+), 83
> deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb.h
> b/drivers/net/ethernet/intel/igb/igb.h index 9e572dd..d15576a 100644
> --- a/drivers/net/ethernet/intel/igb/igb.h
> +++ b/drivers/net/ethernet/intel/igb/igb.h
> @@ -99,7 +99,6 @@ struct vf_data_storage {
>  	u16 pf_vlan; /* When set, guest VLAN config not allowed. */
>  	u16 pf_qos;
>  	u16 tx_rate;
> -	struct pci_dev *vfdev;
>  };
>  
>  #define IGB_VF_FLAG_CTS            0x00000001 /* VF is clear to send
> data */ diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
> b/drivers/net/ethernet/intel/igb/igb_main.c index b7c2d50..9e312da
> 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -172,8 +172,7 @@ static void igb_check_vf_rate_limit(struct
> igb_adapter *); 
>  #ifdef CONFIG_PCI_IOV
>  static int igb_vf_configure(struct igb_adapter *adapter, int vf);
> -static int igb_find_enabled_vfs(struct igb_adapter *adapter);
> -static int igb_check_vf_assignment(struct igb_adapter *adapter);
> +static bool igb_vfs_are_assigned(struct igb_adapter *adapter);
>  #endif
>  
>  #ifdef CONFIG_PM
> @@ -2295,11 +2294,11 @@ static void __devexit igb_remove(struct
> pci_dev *pdev) /* reclaim resources allocated to VFs */
>  	if (adapter->vf_data) {
>  		/* disable iov and allow time for transactions to
> clear */
> -		if (!igb_check_vf_assignment(adapter)) {
> +		if (igb_vfs_are_assigned(adapter)) {
> +			dev_info(&pdev->dev, "Unloading driver while
> VFs are assigned - VFs will not be deallocated\n");
> +		} else {
>  			pci_disable_sriov(pdev);
>  			msleep(500);
> -		} else {
> -			dev_info(&pdev->dev, "VF(s) assigned to
> guests!\n"); }
>  
>  		kfree(adapter->vf_data);
> @@ -2339,7 +2338,7 @@ static void __devinit igb_probe_vfs(struct
> igb_adapter * adapter) #ifdef CONFIG_PCI_IOV
>  	struct pci_dev *pdev = adapter->pdev;
>  	struct e1000_hw *hw = &adapter->hw;
> -	int old_vfs = igb_find_enabled_vfs(adapter);
> +	int old_vfs = pci_num_vf(adapter->pdev);
>  	int i;
>  
>  	/* Virtualization features not supported on i210 family. */
> @@ -5003,102 +5002,43 @@ static int igb_notify_dca(struct
> notifier_block *nb, unsigned long event, static int
> igb_vf_configure(struct igb_adapter *adapter, int vf) {
>  	unsigned char mac_addr[ETH_ALEN];
> -	struct pci_dev *pdev = adapter->pdev;
> -	struct e1000_hw *hw = &adapter->hw;
> -	struct pci_dev *pvfdev;
> -	unsigned int device_id;
> -	u16 thisvf_devfn;
>  
>  	eth_random_addr(mac_addr);
>  	igb_set_vf_mac(adapter, vf, mac_addr);
>  
> -	switch (adapter->hw.mac.type) {
> -	case e1000_82576:
> -		device_id = IGB_82576_VF_DEV_ID;
> -		/* VF Stride for 82576 is 2 */
> -		thisvf_devfn = (pdev->devfn + 0x80 + (vf << 1)) |
> -			(pdev->devfn & 1);
> -		break;
> -	case e1000_i350:
> -		device_id = IGB_I350_VF_DEV_ID;
> -		/* VF Stride for I350 is 4 */
> -		thisvf_devfn = (pdev->devfn + 0x80 + (vf << 2)) |
> -				(pdev->devfn & 3);
> -		break;
> -	default:
> -		device_id = 0;
> -		thisvf_devfn = 0;
> -		break;
> -	}
> -
> -	pvfdev = pci_get_device(hw->vendor_id, device_id, NULL);
> -	while (pvfdev) {
> -		if (pvfdev->devfn == thisvf_devfn)
> -			break;
> -		pvfdev = pci_get_device(hw->vendor_id,
> -					device_id, pvfdev);
> -	}
> -
> -	if (pvfdev)
> -		adapter->vf_data[vf].vfdev = pvfdev;
> -	else
> -		dev_err(&pdev->dev,
> -			"Couldn't find pci dev ptr for VF %4.4x\n",
> -			thisvf_devfn);
> -	return pvfdev != NULL;
> +	return 0;
>  }
>  
> -static int igb_find_enabled_vfs(struct igb_adapter *adapter)
> +static bool igb_vfs_are_assigned(struct igb_adapter *adapter)
>  {
> -	struct e1000_hw *hw = &adapter->hw;
>  	struct pci_dev *pdev = adapter->pdev;
> -	struct pci_dev *pvfdev;
> -	u16 vf_devfn = 0;
> -	u16 vf_stride;
> -	unsigned int device_id;
> -	int vfs_found = 0;
> +	struct pci_dev *vfdev;
> +	int dev_id;
>  
>  	switch (adapter->hw.mac.type) {
>  	case e1000_82576:
> -		device_id = IGB_82576_VF_DEV_ID;
> -		/* VF Stride for 82576 is 2 */
> -		vf_stride = 2;
> +		dev_id = IGB_82576_VF_DEV_ID;
>  		break;
>  	case e1000_i350:
> -		device_id = IGB_I350_VF_DEV_ID;
> -		/* VF Stride for I350 is 4 */
> -		vf_stride = 4;
> +		dev_id = IGB_I350_VF_DEV_ID;
>  		break;
>  	default:
> -		device_id = 0;
> -		vf_stride = 0;
> -		break;
> -	}
> -
> -	vf_devfn = pdev->devfn + 0x80;
> -	pvfdev = pci_get_device(hw->vendor_id, device_id, NULL);
> -	while (pvfdev) {
> -		if (pvfdev->devfn == vf_devfn &&
> -		    (pvfdev->bus->number >= pdev->bus->number))
> -			vfs_found++;
> -		vf_devfn += vf_stride;
> -		pvfdev = pci_get_device(hw->vendor_id,
> -					device_id, pvfdev);
> +		return false;
>  	}
>  
> -	return vfs_found;
> -}
> -
> -static int igb_check_vf_assignment(struct igb_adapter *adapter)
> -{
> -	int i;
> -	for (i = 0; i < adapter->vfs_allocated_count; i++) {
> -		if (adapter->vf_data[i].vfdev) {
> -			if (adapter->vf_data[i].vfdev->dev_flags &
> -			    PCI_DEV_FLAGS_ASSIGNED)
> +	/* loop through all the VFs to see if we own any that are
> assigned */
> +	vfdev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id, NULL);
> +	while (vfdev) {
> +		/* if we don't own it we don't care */
> +		if (vfdev->is_virtfn && vfdev->physfn == pdev) {
> +			/* if it is assigned we cannot release it */
> +			if (vfdev->dev_flags &
> PCI_DEV_FLAGS_ASSIGNED) return true;
>  		}
> +
> +		vfdev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id,
> vfdev); }
> +
>  	return false;
>  }
>