[PATCH 5.4 62/98] i40e: Fix removing driver while bare-metal VFs pass traffic

From: Greg Kroah-Hartman
Date: Tue Dec 01 2020 - 04:09:40 EST


From: Sylwester Dziedziuch <sylwesterx.dziedziuch@xxxxxxxxx>

[ Upstream commit 2980cbd4dce7b1e9bf57df3ced43a7b184986f50 ]

Prevent VFs from resetting when PF driver is being unloaded:
- introduce new pf state: __I40E_VF_RESETS_DISABLED;
- check if pf state has __I40E_VF_RESETS_DISABLED state set,
if so, disable any further VFLR event notifications;
- when i40e_remove (rmmod i40e) is called, disable any resets on
the VFs;

Previously if there were bare-metal VFs passing traffic and PF
driver was removed, there was a possibility of VFs triggering a Tx
timeout right before iavf_remove. This was causing iavf_close to
not be called because there is a check in the beginning of iavf_remove
that bails out early if adapter->state < IAVF_DOWN_PENDING. This
makes it so some resources do not get cleaned up.

Fixes: 6a9ddb36eeb8 ("i40e: disable IOV before freeing resources")
Signed-off-by: Slawomir Laba <slawomirx.laba@xxxxxxxxx>
Signed-off-by: Brett Creeley <brett.creeley@xxxxxxxxx>
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@xxxxxxxxx>
Tested-by: Konrad Jankowski <konrad0.jankowski@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Link: https://lore.kernel.org/r/20201120180640.3654474-1-anthony.l.nguyen@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/intel/i40e/i40e.h | 1 +
drivers/net/ethernet/intel/i40e/i40e_main.c | 22 +++++++++++-----
.../ethernet/intel/i40e/i40e_virtchnl_pf.c | 26 +++++++++++--------
3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 401304d4d5536..cfe99bae8e362 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -150,6 +150,7 @@ enum i40e_state_t {
__I40E_CLIENT_RESET,
__I40E_VIRTCHNL_OP_PENDING,
__I40E_RECOVERY_MODE,
+ __I40E_VF_RESETS_DISABLED, /* disable resets during i40e_remove */
/* This must be last as it determines the size of the BITMAP */
__I40E_STATE_SIZE__,
};
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index b3c3911adfc2e..2b4327416457d 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3988,8 +3988,16 @@ static irqreturn_t i40e_intr(int irq, void *data)
}

if (icr0 & I40E_PFINT_ICR0_VFLR_MASK) {
- ena_mask &= ~I40E_PFINT_ICR0_ENA_VFLR_MASK;
- set_bit(__I40E_VFLR_EVENT_PENDING, pf->state);
+ /* disable any further VFLR event notifications */
+ if (test_bit(__I40E_VF_RESETS_DISABLED, pf->state)) {
+ u32 reg = rd32(hw, I40E_PFINT_ICR0_ENA);
+
+ reg &= ~I40E_PFINT_ICR0_VFLR_MASK;
+ wr32(hw, I40E_PFINT_ICR0_ENA, reg);
+ } else {
+ ena_mask &= ~I40E_PFINT_ICR0_ENA_VFLR_MASK;
+ set_bit(__I40E_VFLR_EVENT_PENDING, pf->state);
+ }
}

if (icr0 & I40E_PFINT_ICR0_GRST_MASK) {
@@ -15345,6 +15353,11 @@ static void i40e_remove(struct pci_dev *pdev)
while (test_bit(__I40E_RESET_RECOVERY_PENDING, pf->state))
usleep_range(1000, 2000);

+ if (pf->flags & I40E_FLAG_SRIOV_ENABLED) {
+ set_bit(__I40E_VF_RESETS_DISABLED, pf->state);
+ i40e_free_vfs(pf);
+ pf->flags &= ~I40E_FLAG_SRIOV_ENABLED;
+ }
/* no more scheduling of any task */
set_bit(__I40E_SUSPENDED, pf->state);
set_bit(__I40E_DOWN, pf->state);
@@ -15371,11 +15384,6 @@ static void i40e_remove(struct pci_dev *pdev)
*/
i40e_notify_client_of_netdev_close(pf->vsi[pf->lan_vsi], false);

- if (pf->flags & I40E_FLAG_SRIOV_ENABLED) {
- i40e_free_vfs(pf);
- pf->flags &= ~I40E_FLAG_SRIOV_ENABLED;
- }
-
i40e_fdir_teardown(pf);

/* If there is a switch structure or any orphans, remove them.
diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 38042d610f82c..09ff3f335ffa6 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -1335,7 +1335,8 @@ static void i40e_cleanup_reset_vf(struct i40e_vf *vf)
* @vf: pointer to the VF structure
* @flr: VFLR was issued or not
*
- * Returns true if the VF is reset, false otherwise.
+ * Returns true if the VF is in reset, resets successfully, or resets
+ * are disabled and false otherwise.
**/
bool i40e_reset_vf(struct i40e_vf *vf, bool flr)
{
@@ -1345,11 +1346,14 @@ bool i40e_reset_vf(struct i40e_vf *vf, bool flr)
u32 reg;
int i;

+ if (test_bit(__I40E_VF_RESETS_DISABLED, pf->state))
+ return true;
+
/* If the VFs have been disabled, this means something else is
* resetting the VF, so we shouldn't continue.
*/
if (test_and_set_bit(__I40E_VF_DISABLE, pf->state))
- return false;
+ return true;

i40e_trigger_vf_reset(vf, flr);

@@ -1513,6 +1517,15 @@ void i40e_free_vfs(struct i40e_pf *pf)

i40e_notify_client_of_vf_enable(pf, 0);

+ /* Disable IOV before freeing resources. This lets any VF drivers
+ * running in the host get themselves cleaned up before we yank
+ * the carpet out from underneath their feet.
+ */
+ if (!pci_vfs_assigned(pf->pdev))
+ pci_disable_sriov(pf->pdev);
+ else
+ dev_warn(&pf->pdev->dev, "VFs are assigned - not disabling SR-IOV\n");
+
/* Amortize wait time by stopping all VFs at the same time */
for (i = 0; i < pf->num_alloc_vfs; i++) {
if (test_bit(I40E_VF_STATE_INIT, &pf->vf[i].vf_states))
@@ -1528,15 +1541,6 @@ void i40e_free_vfs(struct i40e_pf *pf)
i40e_vsi_wait_queues_disabled(pf->vsi[pf->vf[i].lan_vsi_idx]);
}

- /* Disable IOV before freeing resources. This lets any VF drivers
- * running in the host get themselves cleaned up before we yank
- * the carpet out from underneath their feet.
- */
- if (!pci_vfs_assigned(pf->pdev))
- pci_disable_sriov(pf->pdev);
- else
- dev_warn(&pf->pdev->dev, "VFs are assigned - not disabling SR-IOV\n");
-
/* free up VF resources */
tmp = pf->num_alloc_vfs;
pf->num_alloc_vfs = 0;
--
2.27.0