Subject: Re: [PATCH v2 6/7] PCI: Make sure VF's driver get attached after PF's

From: Greg Rose <[email-masked]>
Date: Wed, 15 May 2013 09:12:48 -0700

On Tue, 14 May 2013 19:48:22 -0700
Yinghai Lu <[email-masked]> wrote:

> Found kernel try to load mlx4 drivers for VFs before
> PF's is loaded when the drivers are built-in, and kernel
> command line include probe_vfs=63, num_vfs=63.
> 
> [  169.581682] calling  mlx4_init+0x0/0x119 @ 1
> [  169.595681] mlx4_core: Mellanox ConnectX core driver v1.1 (Dec,
> 2011) [  169.600194] mlx4_core: Initializing 0000:02:00.0
> [  169.616322] mlx4_core 0000:02:00.0: Enabling SR-IOV with 63 VFs
> [  169.724084] pci 0000:02:00.1: [15b3:1002] type 00 class 0x0c0600
> [  169.732442] mlx4_core: Initializing 0000:02:00.1
> [  169.734345] mlx4_core 0000:02:00.1: enabling device (0000 -> 0002)
> [  169.747060] mlx4_core 0000:02:00.1: enabling bus mastering
> [  169.764283] mlx4_core 0000:02:00.1: Detected virtual function -
> running in slave mode [  169.767409] mlx4_core 0000:02:00.1: with
> iommu 3 : domain 11 [  169.785589] mlx4_core 0000:02:00.1: Sending
> reset [  179.790131] mlx4_core 0000:02:00.1: Got slave FLRed from
> Communication channel (ret:0x1) [  181.798661] mlx4_core
> 0000:02:00.1: slave is currently in themiddle of FLR. retrying...(try
> num:1) [  181.803336] mlx4_core 0000:02:00.1: Communication channel
> is not idle.my toggle is 1 (cmd:0x0) ... [  182.078710] mlx4_core
> 0000:02:00.1: slave is currently in themiddle of FLR. retrying...(try
> num:10) [  182.096657] mlx4_core 0000:02:00.1: Communication channel
> is not idle.my toggle is 1 (cmd:0x0) [  182.104935] mlx4_core
> 0000:02:00.1: slave driver version is not supported by the master
> [  182.118570] mlx4_core 0000:02:00.1: Communication channel is not
> idle.my toggle is 1 (cmd:0x0) [  182.138190] mlx4_core 0000:02:00.1:
> Failed to initialize slave [  182.141728] mlx4_core: probe of
> 0000:02:00.1 failed with error -5
> 
> It turns that this also happen for hotadd path even drivers are
> compiled as modules and if they are loaded. Esp some VF share the
> same driver with PF.
> 
> calling path:
> 	device driver probe
> 		==> pci_enable_sriov
> 			==> virtfn_add
> 				==> pci_dev_add
> 				==> pci_bus_device_add
> when pci_bus_device_add is called, the VF's driver will be attached.
> and at that time PF's driver does not finish yet.
> 
> Need to move out pci_bus_device_add from virtfn_add and call it
> later.
> 
> bnx2x and qlcnic are ok, because it does not modules command line
> to enable sriov. They must use sysfs to enable it.
> 
> be2net is ok, according to Sathya Perla,
> he fixed this issue in be2net with the following patch (commit
> b4c1df93) http://marc.info/?l=linux-netdev&m=136801459808765&w=2
> 
> For igb and ixgbe is ok, as Alex Duyck said:
> | The VF driver should be able to be loaded when the PF driver is not
> | present.  We handle it in igb and ixgbe last I checked, and I don't
> see | any reason why it cannot be handled in all other VF drivers.
> I'm not | saying the VF has to be able to fully functional, but it
> should be able | to detect the PF becoming enabled and then bring
> itself to a fully | functional state.  To not handle that case is a
> bug.
> 
> Looks like the patch will help enic, mlx4, efx, vxge and lpfc now.
> 
> -v2: don't use schedule_callback, and initcall after Alex's patch.
> 	pci: Avoid reentrant calls to work_on_cpu
> 
> Signed-off-by: Yinghai Lu <[email-masked]>
> Cc: Alexander Duyck <[email-masked]>
> Cc: Yan Burman <[email-masked]>
> Cc: Sathya Perla <[email-masked]>
> Cc: [email-masked]

I'm really not a fan of this.  Seems to me the tail is wagging the dog
here.  Fix the driver to work without a PF driver being present.

- Greg

> 
> ---
>  drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c    |    7 ++
>  drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c      |    4 +
>  drivers/net/ethernet/cisco/enic/enic_main.c          |    2 
>  drivers/net/ethernet/emulex/benet/be_main.c          |    4 +
>  drivers/net/ethernet/intel/igb/igb_main.c            |   11 +++-
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c        |    2 
>  drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c       |    9 ++-
>  drivers/net/ethernet/mellanox/mlx4/main.c            |    3 +
>  drivers/net/ethernet/neterion/vxge/vxge-main.c       |    3 +
>  drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c |    5 +-
>  drivers/net/ethernet/sfc/efx.c                       |    1 
>  drivers/pci/iov.c                                    |   47
> ++++++++++++++++---
> drivers/scsi/lpfc/lpfc_init.c                        |    2
> include/linux/pci.h                                  |    4 + 14
> files changed, 90 insertions(+), 14 deletions(-)
> 
> Index: linux-2.6/drivers/net/ethernet/mellanox/mlx4/main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/mellanox/mlx4/main.c
> +++ linux-2.6/drivers/net/ethernet/mellanox/mlx4/main.c
> @@ -2308,6 +2308,9 @@ slave_start:
>  	priv->pci_dev_data = pci_dev_data;
>  	pci_set_drvdata(pdev, dev);
>  
> +	if (dev->flags & MLX4_FLAG_SRIOV)
> +		pci_bus_add_device_vfs(pdev);
> +
>  	return 0;
>  
>  err_port:
> Index: linux-2.6/drivers/pci/iov.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/iov.c
> +++ linux-2.6/drivers/pci/iov.c
> @@ -66,7 +66,8 @@ static void virtfn_remove_bus(struct pci
>  		pci_remove_bus(child);
>  }
>  
> -static int virtfn_add(struct pci_dev *dev, int id, int reset)
> +static int virtfn_add(struct pci_dev *dev, int id, int reset,
> +			struct pci_dev **ret)
>  {
>  	int i;
>  	int rc;
> @@ -116,7 +117,6 @@ static int virtfn_add(struct pci_dev *de
>  	pci_device_add(virtfn, virtfn->bus);
>  	mutex_unlock(&iov->dev->sriov->lock);
>  
> -	rc = pci_bus_add_device(virtfn);
>  	sprintf(buf, "virtfn%u", id);
>  	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj,
> buf); if (rc)
> @@ -127,6 +127,8 @@ static int virtfn_add(struct pci_dev *de
>  
>  	kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
>  
> +	if (ret)
> +		*ret = virtfn;
>  	return 0;
>  
>  failed2:
> @@ -141,6 +143,26 @@ failed1:
>  	return rc;
>  }
>  
> +void pci_bus_add_device_vfs(struct pci_dev *pdev)
> +{
> +	int rc;
> +	struct pci_dev *dev;
> +
> +       /* only search if it is a PF */
> +	if (!pdev->is_physfn)
> +		return;
> +
> +	/* loop through all the VFs to see if we own and is not
> added yet*/
> +	dev = pci_get_device(pdev->vendor, PCI_ANY_ID, NULL);
> +	while (dev) {
> +		if (dev->is_virtfn && dev->physfn == pdev
> && !dev->is_added)
> +			rc = pci_bus_add_device(dev);
> +
> +		dev = pci_get_device(pdev->vendor, PCI_ANY_ID, dev);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(pci_bus_add_device_vfs);
> +
>  static void virtfn_remove(struct pci_dev *dev, int id, int reset)
>  {
>  	char buf[VIRTFN_ID_LEN];
> @@ -204,6 +226,7 @@ static int sriov_migration(struct pci_de
>  static void sriov_migration_task(struct work_struct *work)
>  {
>  	int i;
> +	int rc;
>  	u8 state;
>  	u16 status;
>  	struct pci_sriov *iov = container_of(work, struct pci_sriov,
> mtask); @@ -213,14 +236,24 @@ static void sriov_migration_task(struct
>  		if (state == PCI_SRIOV_VFM_MI) {
>  			writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
>  			state = readb(iov->mstate + i);
> -			if (state == PCI_SRIOV_VFM_AV)
> -				virtfn_add(iov->self, i, 1);
> +			if (state == PCI_SRIOV_VFM_AV) {
> +				struct pci_dev *virtfn = NULL;
> +
> +				virtfn_add(iov->self, i, 1, &virtfn);
> +				if (virtfn)
> +					rc =
> pci_bus_add_device(virtfn);
> +			}
>  		} else if (state == PCI_SRIOV_VFM_MO) {
>  			virtfn_remove(iov->self, i, 1);
>  			writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
>  			state = readb(iov->mstate + i);
> -			if (state == PCI_SRIOV_VFM_AV)
> -				virtfn_add(iov->self, i, 0);
> +			if (state == PCI_SRIOV_VFM_AV) {
> +				struct pci_dev *virtfn = NULL;
> +
> +				virtfn_add(iov->self, i, 0, &virtfn);
> +				if (virtfn)
> +					rc =
> pci_bus_add_device(virtfn);
> +			}
>  		}
>  	}
>  
> @@ -356,7 +389,7 @@ static int sriov_enable(struct pci_dev *
>  		initial = nr_virtfn;
>  
>  	for (i = 0; i < initial; i++) {
> -		rc = virtfn_add(dev, i, 0);
> +		rc = virtfn_add(dev, i, 0, NULL);
>  		if (rc)
>  			goto failed;
>  	}
> Index: linux-2.6/include/linux/pci.h
> ===================================================================
> --- linux-2.6.orig/include/linux/pci.h
> +++ linux-2.6/include/linux/pci.h
> @@ -1659,6 +1659,7 @@ void __iomem *pci_ioremap_bar(struct pci
>  
>  #ifdef CONFIG_PCI_IOV
>  int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
> +void pci_bus_add_device_vfs(struct pci_dev *dev);
>  void pci_disable_sriov(struct pci_dev *dev);
>  irqreturn_t pci_sriov_migration(struct pci_dev *dev);
>  int pci_num_vf(struct pci_dev *dev);
> @@ -1670,6 +1671,9 @@ static inline int pci_enable_sriov(struc
>  {
>  	return -ENODEV;
>  }
> +static inline void pci_bus_add_device_vfs(struct pci_dev *dev)
> +{
> +}
>  static inline void pci_disable_sriov(struct pci_dev *dev)
>  {
>  }
> Index: linux-2.6/drivers/net/ethernet/intel/igb/igb_main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/intel/igb/igb_main.c
> +++ linux-2.6/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -2366,6 +2366,9 @@ static int igb_probe(struct pci_dev *pde
>  	}
>  
>  	pm_runtime_put_noidle(&pdev->dev);
> +
> +	pci_bus_add_device_vfs(pdev);
> +
>  	return 0;
>  
>  err_register:
> @@ -7278,8 +7281,12 @@ static int igb_pci_sriov_configure(struc
>  #ifdef CONFIG_PCI_IOV
>  	if (num_vfs == 0)
>  		return igb_pci_disable_sriov(dev);
> -	else
> -		return igb_pci_enable_sriov(dev, num_vfs);
> +	else {
> +		int ret = igb_pci_enable_sriov(dev, num_vfs);
> +		if (ret > 0)
> +			pci_bus_add_device_vfs(dev);
> +		return ret;
> +	}
>  #endif
>  	return 0;
>  }
> Index: linux-2.6/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
> +++ linux-2.6/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
> @@ -346,8 +346,13 @@ int ixgbe_pci_sriov_configure(struct pci
>  {
>  	if (num_vfs == 0)
>  		return ixgbe_pci_sriov_disable(dev);
> -	else
> -		return ixgbe_pci_sriov_enable(dev, num_vfs);
> +	else {
> +		int ret = ixgbe_pci_sriov_enable(dev, num_vfs);
> +
> +		if (ret > 0)
> +			pci_bus_add_device_vfs(dev);
> +		return ret;
> +	}
>  }
>  
>  static int ixgbe_set_vf_multicasts(struct ixgbe_adapter *adapter,
> Index: linux-2.6/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ linux-2.6/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -7658,6 +7658,8 @@ skip_sriov:
>  			IXGBE_LINK_SPEED_10GB_FULL |
> IXGBE_LINK_SPEED_1GB_FULL, true);
>  
> +	pci_bus_add_device_vfs(pdev);
> +
>  	return 0;
>  
>  err_register:
> Index: linux-2.6/drivers/scsi/lpfc/lpfc_init.c
> ===================================================================
> --- linux-2.6.orig/drivers/scsi/lpfc/lpfc_init.c
> +++ linux-2.6/drivers/scsi/lpfc/lpfc_init.c
> @@ -10582,6 +10582,8 @@ lpfc_pci_probe_one(struct pci_dev *pdev,
>  	else
>  		rc = lpfc_pci_probe_one_s3(pdev, pid);
>  
> +	pci_bus_add_device_vfs(pdev);
> +
>  	return rc;
>  }
>  
> Index: linux-2.6/drivers/net/ethernet/emulex/benet/be_main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/emulex/benet/be_main.c
> +++ linux-2.6/drivers/net/ethernet/emulex/benet/be_main.c
> @@ -4111,6 +4111,7 @@ static int lancer_recover_func(struct be
>  	if (status)
>  		goto err;
>  
> +	pci_bus_add_device_vfs(adapter->pdev);
>  	if (netif_running(adapter->netdev)) {
>  		status = be_open(adapter->netdev);
>  		if (status)
> @@ -4327,6 +4328,8 @@ static int be_probe(struct pci_dev *pdev
>  	dev_info(&pdev->dev, "%s: %s %s port %c\n", nic_name(pdev),
>  		 func_name(adapter), mc_name(adapter), port_name);
>  
> +	pci_bus_add_device_vfs(pdev);
> +
>  	return 0;
>  
>  unsetup:
> @@ -4398,6 +4401,7 @@ static int be_resume(struct pci_dev *pde
>  		rtnl_unlock();
>  	}
>  
> +	pci_bus_add_device_vfs(adapter->pdev);
>  	schedule_delayed_work(&adapter->func_recovery_work,
>  			      msecs_to_jiffies(1000));
>  	netif_device_attach(netdev);
> Index: linux-2.6/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
> ===================================================================
> ---
> linux-2.6.orig/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
> +++ linux-2.6/drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c @@
> -568,8 +568,11 @@ int qlcnic_pci_sriov_configure(struct pc 
>  	if (num_vfs == 0)
>  		err = qlcnic_pci_sriov_disable(adapter);
> -	else
> +	else {
>  		err = qlcnic_pci_sriov_enable(adapter, num_vfs);
> +		if (err > 0)
> +			pci_bus_add_device_vfs(dev);
> +	}
>  
>  	clear_bit(__QLCNIC_RESETTING, &adapter->state);
>  	return err;
> Index: linux-2.6/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
> +++ linux-2.6/drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
> @@ -3048,7 +3048,12 @@ int bnx2x_sriov_configure(struct pci_dev
>  		pci_disable_sriov(dev);
>  		return 0;
>  	} else {
> -		return bnx2x_enable_sriov(bp);
> +		int ret = bnx2x_enable_sriov(bp);
> +
> +		if (ret > 0)
> +			pci_bus_add_device_vfs(dev);
> +
> +		return 0;
>  	}
>  }
>  
> Index: linux-2.6/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> +++ linux-2.6/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> @@ -5749,10 +5749,12 @@ static int init_one(struct pci_dev *pdev
>  sriov:
>  #ifdef CONFIG_PCI_IOV
>  	if (func < ARRAY_SIZE(num_vf) && num_vf[func] > 0)
> -		if (pci_enable_sriov(pdev, num_vf[func]) == 0)
> +		if (pci_enable_sriov(pdev, num_vf[func]) == 0) {
>  			dev_info(&pdev->dev,
>  				 "instantiated %u virtual
> functions\n", num_vf[func]);
> +			pci_bus_add_device_vfs(pdev);
> +		}
>  #endif
>  	return 0;
>  
> Index: linux-2.6/drivers/net/ethernet/cisco/enic/enic_main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/cisco/enic/enic_main.c
> +++ linux-2.6/drivers/net/ethernet/cisco/enic/enic_main.c
> @@ -2524,6 +2524,8 @@ static int enic_probe(struct pci_dev *pd
>  		goto err_out_dev_deinit;
>  	}
>  
> +	pci_bus_add_device_vfs(pdev);
> +
>  	return 0;
>  
>  err_out_dev_deinit:
> Index: linux-2.6/drivers/net/ethernet/neterion/vxge/vxge-main.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/neterion/vxge/vxge-main.c
> +++ linux-2.6/drivers/net/ethernet/neterion/vxge/vxge-main.c
> @@ -4731,6 +4731,9 @@ vxge_probe(struct pci_dev *pdev, const s
>  		vxge_hw_device_trace_level_get(hldev));
>  
>  	kfree(ll_config);
> +
> +	pci_bus_add_device_vfs(pdev);
> +
>  	return 0;
>  
>  _exit6:
> Index: linux-2.6/drivers/net/ethernet/sfc/efx.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/ethernet/sfc/efx.c
> +++ linux-2.6/drivers/net/ethernet/sfc/efx.c
> @@ -2824,6 +2824,7 @@ static int efx_pci_probe(struct pci_dev
>  		netif_warn(efx, probe, efx->net_dev,
>  			   "pci_enable_pcie_error_reporting failed
> (%d)\n", rc); 
> +	pci_bus_add_device_vfs(pci_dev);
>  	return 0;
>  
>   fail4:
> --
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