i40e: Fix kernel oops when i40e driver removes VF's

Fix the reason of kernel oops when i40e driver removed VFs.
Added new __I40E_VFS_RELEASING state to signalize releasing
process by PF, that it makes possible to exit of reset VF procedure.
Without this patch, it is possible to suspend the VFs reset by
releasing VFs resources procedure. Retrying the reset after the
timeout works on the freed VF memory causing a kernel oops.

Fixes: d43d60e5eb95 ("i40e: ensure reset occurs when disabling VF")
Signed-off-by: Eryk Rybak <eryk.roch.rybak@intel.com>
Signed-off-by: Grzegorz Szczurek <grzegorzx.szczurek@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index cd53981fa5e092469e3568ec4e6520ee14e23355..15f93b3550990b5e768b073a9f9171c64e61a2a7 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -142,6 +142,7 @@ enum i40e_state_t {
        __I40E_VIRTCHNL_OP_PENDING,
        __I40E_RECOVERY_MODE,
        __I40E_VF_RESETS_DISABLED,      /* disable resets during i40e_remove */
+       __I40E_VFS_RELEASING,
        /* 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 1b6ec9be155a6352eb1a330172c50b70b1bad98a..5d301a466f5c516cfd5ed745ee7981d12c4aab07 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -137,6 +137,7 @@ void i40e_vc_notify_vf_reset(struct i40e_vf *vf)
  **/
 static inline void i40e_vc_disable_vf(struct i40e_vf *vf)
 {
+       struct i40e_pf *pf = vf->pf;
        int i;
 
        i40e_vc_notify_vf_reset(vf);
@@ -147,6 +148,11 @@ static inline void i40e_vc_disable_vf(struct i40e_vf *vf)
         * ensure a reset.
         */
        for (i = 0; i < 20; i++) {
+               /* If PF is in VFs releasing state reset VF is impossible,
+                * so leave it.
+                */
+               if (test_bit(__I40E_VFS_RELEASING, pf->state))
+                       return;
                if (i40e_reset_vf(vf, false))
                        return;
                usleep_range(10000, 20000);
@@ -1574,6 +1580,8 @@ void i40e_free_vfs(struct i40e_pf *pf)
 
        if (!pf->vf)
                return;
+
+       set_bit(__I40E_VFS_RELEASING, pf->state);
        while (test_and_set_bit(__I40E_VF_DISABLE, pf->state))
                usleep_range(1000, 2000);
 
@@ -1631,6 +1639,7 @@ void i40e_free_vfs(struct i40e_pf *pf)
                }
        }
        clear_bit(__I40E_VF_DISABLE, pf->state);
+       clear_bit(__I40E_VFS_RELEASING, pf->state);
 }
 
 #ifdef CONFIG_PCI_IOV