i40e: Protect access to VF control methods

A scenario has been found in which simultaneous
addition/removal and modification of VF's might cause
unstable behaviour, up to and including kernel panics.

Protect the methods that create/modify/destroy VF's
by locking them behind an atomically set bit in PF status
bitfield.

Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 876cac3..5595a46 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -146,6 +146,7 @@ enum i40e_state_t {
        __I40E_CLIENT_SERVICE_REQUESTED,
        __I40E_CLIENT_L2_CHANGE,
        __I40E_CLIENT_RESET,
+       __I40E_VIRTCHNL_OP_PENDING,
        /* This must be last as it determines the size of the BITMAP */
        __I40E_STATE_SIZE__,
 };

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index ac5698e..8e0a247 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -1675,13 +1675,20 @@ err_out:
 int i40e_pci_sriov_configure(struct pci_dev *pdev, int num_vfs)
 {
        struct i40e_pf *pf = pci_get_drvdata(pdev);
+       int ret = 0;
+
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
 
        if (num_vfs) {
                if (!(pf->flags & I40E_FLAG_VEB_MODE_ENABLED)) {
                        pf->flags |= I40E_FLAG_VEB_MODE_ENABLED;
                        i40e_do_reset_safe(pf, I40E_PF_RESET_FLAG);
                }
-               return i40e_pci_sriov_enable(pdev, num_vfs);
+               ret = i40e_pci_sriov_enable(pdev, num_vfs);
+               goto sriov_configure_out;
        }
 
        if (!pci_vfs_assigned(pf->pdev)) {
@@ -1690,9 +1697,12 @@ int i40e_pci_sriov_configure(struct pci_dev *pdev, int num_vfs)
                i40e_do_reset_safe(pf, I40E_PF_RESET_FLAG);
        } else {
                dev_warn(&pdev->dev, "Unable to free VFs because some are assigned to VMs.\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto sriov_configure_out;
        }
-       return 0;
+sriov_configure_out:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
+       return ret;
 }
 
 /***********************virtual channel routines******************/
@@ -3893,6 +3903,11 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
                goto error_param;
        }
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        if (is_multicast_ether_addr(mac)) {
                dev_err(&pf->pdev->dev,
                        "Invalid Ethernet address %pM for VF %d\n", mac, vf_id);
@@ -3941,6 +3956,7 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
        dev_info(&pf->pdev->dev, "Bring down and up the VF interface to make this change effective.\n");
 
 error_param:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }
 
@@ -3992,6 +4008,11 @@ int i40e_ndo_set_vf_port_vlan(struct net_device *netdev, int vf_id,
        struct i40e_vf *vf;
        int ret = 0;
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        /* validate the request */
        ret = i40e_validate_vf(pf, vf_id);
        if (ret)
@@ -4107,6 +4128,7 @@ int i40e_ndo_set_vf_port_vlan(struct net_device *netdev, int vf_id,
        ret = 0;
 
 error_pvid:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }
 
@@ -4128,6 +4150,11 @@ int i40e_ndo_set_vf_bw(struct net_device *netdev, int vf_id, int min_tx_rate,
        struct i40e_vf *vf;
        int ret = 0;
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        /* validate the request */
        ret = i40e_validate_vf(pf, vf_id);
        if (ret)
@@ -4154,6 +4181,7 @@ int i40e_ndo_set_vf_bw(struct net_device *netdev, int vf_id, int min_tx_rate,
 
        vf->tx_rate = max_tx_rate;
 error:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }
 
@@ -4174,6 +4202,11 @@ int i40e_ndo_get_vf_config(struct net_device *netdev,
        struct i40e_vf *vf;
        int ret = 0;
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        /* validate the request */
        ret = i40e_validate_vf(pf, vf_id);
        if (ret)
@@ -4209,6 +4242,7 @@ int i40e_ndo_get_vf_config(struct net_device *netdev,
        ret = 0;
 
 error_param:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }
 
@@ -4230,6 +4264,11 @@ int i40e_ndo_set_vf_link_state(struct net_device *netdev, int vf_id, int link)
        int abs_vf_id;
        int ret = 0;
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        /* validate the request */
        if (vf_id >= pf->num_alloc_vfs) {
                dev_err(&pf->pdev->dev, "Invalid VF Identifier %d\n", vf_id);
@@ -4273,6 +4312,7 @@ int i40e_ndo_set_vf_link_state(struct net_device *netdev, int vf_id, int link)
                               0, (u8 *)&pfe, sizeof(pfe), NULL);
 
 error_out:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }
 
@@ -4294,6 +4334,11 @@ int i40e_ndo_set_vf_spoofchk(struct net_device *netdev, int vf_id, bool enable)
        struct i40e_vf *vf;
        int ret = 0;
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        /* validate the request */
        if (vf_id >= pf->num_alloc_vfs) {
                dev_err(&pf->pdev->dev, "Invalid VF Identifier %d\n", vf_id);
@@ -4327,6 +4372,7 @@ int i40e_ndo_set_vf_spoofchk(struct net_device *netdev, int vf_id, bool enable)
                ret = -EIO;
        }
 out:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }
 
@@ -4345,15 +4391,22 @@ int i40e_ndo_set_vf_trust(struct net_device *netdev, int vf_id, bool setting)
        struct i40e_vf *vf;
        int ret = 0;
 
+       if (test_and_set_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state)) {
+               dev_warn(&pf->pdev->dev, "Unable to configure VFs, other operation is pending.\n");
+               return -EAGAIN;
+       }
+
        /* validate the request */
        if (vf_id >= pf->num_alloc_vfs) {
                dev_err(&pf->pdev->dev, "Invalid VF Identifier %d\n", vf_id);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out;
        }
 
        if (pf->flags & I40E_FLAG_MFP_ENABLED) {
                dev_err(&pf->pdev->dev, "Trusted VF not supported in MFP mode.\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out;
        }
 
        vf = &pf->vf[vf_id];
@@ -4376,5 +4429,6 @@ int i40e_ndo_set_vf_trust(struct net_device *netdev, int vf_id, bool setting)
        }
 
 out:
+       clear_bit(__I40E_VIRTCHNL_OP_PENDING, pf->state);
        return ret;
 }