[Intel-wired-lan] [PATCH net] i40e: Fix kernel oops when i40e driver removes VF's

Eryk Rybak eryk.roch.rybak at intel.com
Thu Feb 18 11:15:26 UTC 2021


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 at intel.com>
Signed-off-by: Grzegorz Szczurek <grzegorzx.szczurek at intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov at intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e.h             | 1 +
 drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 118473d..fe12587 100644
--- 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 1b6ec9b..0c6cbe9 100644
--- 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

base-commit: e4b62cf7559f2ef9a022de235e5a09a8d7ded520
-- 
2.20.1



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