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* [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e)
@ 2024-03-26 16:23 Tony Nguyen
  2024-03-26 16:23 ` [PATCH net 1/3] i40e: Enforce software interrupt during busy-poll exit Tony Nguyen
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Tony Nguyen @ 2024-03-26 16:23 UTC (permalink / raw)
  To: davem, kuba, pabeni, edumazet, netdev; +Cc: Tony Nguyen

This series contains updates to i40e driver only.

Ivan Vecera resolves an issue where descriptors could be missed when
exiting busy poll.

Aleksandr corrects counting of MAC filters to only include new or active
filters and resolves possible use of incorrect/stale 'vf' variable.

The following are changes since commit c1fd3a9433a2bf5a1c272384c2150e48d69df1a4:
  Merge branch 'there-are-some-bugfix-for-the-hns3-ethernet-driver'
and are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue 40GbE

Aleksandr Loktionov (2):
  i40e: fix i40e_count_filters() to count only active/new filters
  i40e: fix vf may be used uninitialized in this function warning

Ivan Vecera (1):
  i40e: Enforce software interrupt during busy-poll exit

 drivers/net/ethernet/intel/i40e/i40e.h        |  1 +
 drivers/net/ethernet/intel/i40e/i40e_main.c   | 13 ++-
 .../net/ethernet/intel/i40e/i40e_register.h   |  3 +
 drivers/net/ethernet/intel/i40e/i40e_txrx.c   | 82 ++++++++++++++-----
 drivers/net/ethernet/intel/i40e/i40e_txrx.h   |  1 +
 .../ethernet/intel/i40e/i40e_virtchnl_pf.c    | 34 ++++----
 6 files changed, 93 insertions(+), 41 deletions(-)

-- 
2.41.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH net 1/3] i40e: Enforce software interrupt during busy-poll exit
  2024-03-26 16:23 [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) Tony Nguyen
@ 2024-03-26 16:23 ` Tony Nguyen
  2024-03-26 16:23 ` [PATCH net 2/3] i40e: fix i40e_count_filters() to count only active/new filters Tony Nguyen
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: Tony Nguyen @ 2024-03-26 16:23 UTC (permalink / raw)
  To: davem, kuba, pabeni, edumazet, netdev
  Cc: Ivan Vecera, anthony.l.nguyen, Hugo Ferreira, Michal Schmidt,
	Jesse Brandeburg, Pucha Himasekhar Reddy

From: Ivan Vecera <ivecera@redhat.com>

As for ice bug fixed by commit b7306b42beaf ("ice: manage interrupts
during poll exit") followed by commit 23be7075b318 ("ice: fix software
generating extra interrupts") I'm seeing the similar issue also with
i40e driver.

In certain situation when busy-loop is enabled together with adaptive
coalescing, the driver occasionally misses that there are outstanding
descriptors to clean when exiting busy poll.

Try to catch the remaining work by triggering a software interrupt
when exiting busy poll. No extra interrupts will be generated when
busy polling is not used.

The issue was found when running sockperf ping-pong tcp test with
adaptive coalescing and busy poll enabled (50 as value busy_pool
and busy_read sysctl knobs) and results in huge latency spikes
with more than 100000us.

The fix is inspired from the ice driver and do the following:
1) During napi poll exit in case of busy-poll (napo_complete_done()
   returns false) this is recorded to q_vector that we were in busy
   loop.
2) Extends i40e_buildreg_itr() to be able to add an enforced software
   interrupt into built value
2) In i40e_update_enable_itr() enforces a software interrupt trigger
   if we are exiting busy poll to catch any pending clean-ups
3) Reuses unused 3rd ITR (interrupt throttle) index and set it to
   20K interrupts per second to limit the number of these sw interrupts.

Test results
============
Prior:
[root@dell-per640-07 net]# sockperf ping-pong -i 10.9.9.1 --tcp -m 1000 --mps=max -t 120
sockperf: == version #3.10-no.git ==
sockperf[CLIENT] send on:sockperf: using recvfrom() to block on socket(s)

[ 0] IP = 10.9.9.1        PORT = 11111 # TCP
sockperf: Warmup stage (sending a few dummy messages)...
sockperf: Starting test...
sockperf: Test end (interrupted by timer)
sockperf: Test ended
sockperf: [Total Run] RunTime=119.999 sec; Warm up time=400 msec; SentMessages=2438563; ReceivedMessages=2438562
sockperf: ========= Printing statistics for Server No: 0
sockperf: [Valid Duration] RunTime=119.549 sec; SentMessages=2429473; ReceivedMessages=2429473
sockperf: ====> avg-latency=24.571 (std-dev=93.297, mean-ad=4.904, median-ad=1.510, siqr=1.063, cv=3.797, std-error=0.060, 99.0% ci=[24.417, 24.725])
sockperf: # dropped messages = 0; # duplicated messages = 0; # out-of-order messages = 0
sockperf: Summary: Latency is 24.571 usec
sockperf: Total 2429473 observations; each percentile contains 24294.73 observations
sockperf: ---> <MAX> observation = 103294.331
sockperf: ---> percentile 99.999 =   45.633
sockperf: ---> percentile 99.990 =   37.013
sockperf: ---> percentile 99.900 =   35.910
sockperf: ---> percentile 99.000 =   33.390
sockperf: ---> percentile 90.000 =   28.626
sockperf: ---> percentile 75.000 =   27.741
sockperf: ---> percentile 50.000 =   26.743
sockperf: ---> percentile 25.000 =   25.614
sockperf: ---> <MIN> observation =   12.220

After:
[root@dell-per640-07 net]# sockperf ping-pong -i 10.9.9.1 --tcp -m 1000 --mps=max -t 120
sockperf: == version #3.10-no.git ==
sockperf[CLIENT] send on:sockperf: using recvfrom() to block on socket(s)

[ 0] IP = 10.9.9.1        PORT = 11111 # TCP
sockperf: Warmup stage (sending a few dummy messages)...
sockperf: Starting test...
sockperf: Test end (interrupted by timer)
sockperf: Test ended
sockperf: [Total Run] RunTime=119.999 sec; Warm up time=400 msec; SentMessages=2400055; ReceivedMessages=2400054
sockperf: ========= Printing statistics for Server No: 0
sockperf: [Valid Duration] RunTime=119.549 sec; SentMessages=2391186; ReceivedMessages=2391186
sockperf: ====> avg-latency=24.965 (std-dev=5.934, mean-ad=4.642, median-ad=1.485, siqr=1.067, cv=0.238, std-error=0.004, 99.0% ci=[24.955, 24.975])
sockperf: # dropped messages = 0; # duplicated messages = 0; # out-of-order messages = 0
sockperf: Summary: Latency is 24.965 usec
sockperf: Total 2391186 observations; each percentile contains 23911.86 observations
sockperf: ---> <MAX> observation =  195.841
sockperf: ---> percentile 99.999 =   45.026
sockperf: ---> percentile 99.990 =   39.009
sockperf: ---> percentile 99.900 =   35.922
sockperf: ---> percentile 99.000 =   33.482
sockperf: ---> percentile 90.000 =   28.902
sockperf: ---> percentile 75.000 =   27.821
sockperf: ---> percentile 50.000 =   26.860
sockperf: ---> percentile 25.000 =   25.685
sockperf: ---> <MIN> observation =   12.277

Fixes: 0bcd952feec7 ("ethernet/intel: consolidate NAPI and NAPI exit")
Reported-by: Hugo Ferreira <hferreir@redhat.com>
Reviewed-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e.h        |  1 +
 drivers/net/ethernet/intel/i40e/i40e_main.c   |  6 ++
 .../net/ethernet/intel/i40e/i40e_register.h   |  3 +
 drivers/net/ethernet/intel/i40e/i40e_txrx.c   | 82 ++++++++++++++-----
 drivers/net/ethernet/intel/i40e/i40e_txrx.h   |  1 +
 5 files changed, 72 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index ba24f3fa92c3..2fbabcdb5bb5 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -955,6 +955,7 @@ struct i40e_q_vector {
 	struct rcu_head rcu;	/* to avoid race with update stats on free */
 	char name[I40E_INT_NAME_STR_LEN];
 	bool arm_wb_state;
+	bool in_busy_poll;
 	int irq_num;		/* IRQ assigned to this q_vector */
 } ____cacheline_internodealigned_in_smp;
 
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index f86578857e8a..6576a0081093 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3911,6 +3911,12 @@ static void i40e_vsi_configure_msix(struct i40e_vsi *vsi)
 		     q_vector->tx.target_itr >> 1);
 		q_vector->tx.current_itr = q_vector->tx.target_itr;
 
+		/* Set ITR for software interrupts triggered after exiting
+		 * busy-loop polling.
+		 */
+		wr32(hw, I40E_PFINT_ITRN(I40E_SW_ITR, vector - 1),
+		     I40E_ITR_20K);
+
 		wr32(hw, I40E_PFINT_RATEN(vector - 1),
 		     i40e_intrl_usec_to_reg(vsi->int_rate_limit));
 
diff --git a/drivers/net/ethernet/intel/i40e/i40e_register.h b/drivers/net/ethernet/intel/i40e/i40e_register.h
index 14ab642cafdb..432afbb64201 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_register.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_register.h
@@ -333,8 +333,11 @@
 #define I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT 3
 #define I40E_PFINT_DYN_CTLN_ITR_INDX_MASK I40E_MASK(0x3, I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT)
 #define I40E_PFINT_DYN_CTLN_INTERVAL_SHIFT 5
+#define I40E_PFINT_DYN_CTLN_INTERVAL_MASK I40E_MASK(0xFFF, I40E_PFINT_DYN_CTLN_INTERVAL_SHIFT)
 #define I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_SHIFT 24
 #define I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK I40E_MASK(0x1, I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_SHIFT)
+#define I40E_PFINT_DYN_CTLN_SW_ITR_INDX_SHIFT 25
+#define I40E_PFINT_DYN_CTLN_SW_ITR_INDX_MASK I40E_MASK(0x3, I40E_PFINT_DYN_CTLN_SW_ITR_INDX_SHIFT)
 #define I40E_PFINT_ICR0 0x00038780 /* Reset: CORER */
 #define I40E_PFINT_ICR0_INTEVENT_SHIFT 0
 #define I40E_PFINT_ICR0_INTEVENT_MASK I40E_MASK(0x1, I40E_PFINT_ICR0_INTEVENT_SHIFT)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 0d7177083708..1a12b732818e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2630,7 +2630,22 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget,
 	return failure ? budget : (int)total_rx_packets;
 }
 
-static inline u32 i40e_buildreg_itr(const int type, u16 itr)
+/**
+ * i40e_buildreg_itr - build a value for writing to I40E_PFINT_DYN_CTLN register
+ * @itr_idx: interrupt throttling index
+ * @interval: interrupt throttling interval value in usecs
+ * @force_swint: force software interrupt
+ *
+ * The function builds a value for I40E_PFINT_DYN_CTLN register that
+ * is used to update interrupt throttling interval for specified ITR index
+ * and optionally enforces a software interrupt. If the @itr_idx is equal
+ * to I40E_ITR_NONE then no interval change is applied and only @force_swint
+ * parameter is taken into account. If the interval change and enforced
+ * software interrupt are not requested then the built value just enables
+ * appropriate vector interrupt.
+ **/
+static u32 i40e_buildreg_itr(enum i40e_dyn_idx itr_idx, u16 interval,
+			     bool force_swint)
 {
 	u32 val;
 
@@ -2644,23 +2659,33 @@ static inline u32 i40e_buildreg_itr(const int type, u16 itr)
 	 * an event in the PBA anyway so we need to rely on the automask
 	 * to hold pending events for us until the interrupt is re-enabled
 	 *
-	 * The itr value is reported in microseconds, and the register
-	 * value is recorded in 2 microsecond units. For this reason we
-	 * only need to shift by the interval shift - 1 instead of the
-	 * full value.
+	 * We have to shift the given value as it is reported in microseconds
+	 * and the register value is recorded in 2 microsecond units.
 	 */
-	itr &= I40E_ITR_MASK;
+	interval >>= 1;
 
+	/* 1. Enable vector interrupt
+	 * 2. Update the interval for the specified ITR index
+	 *    (I40E_ITR_NONE in the register is used to indicate that
+	 *     no interval update is requested)
+	 */
 	val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
-	      (type << I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT) |
-	      (itr << (I40E_PFINT_DYN_CTLN_INTERVAL_SHIFT - 1));
+	      FIELD_PREP(I40E_PFINT_DYN_CTLN_ITR_INDX_MASK, itr_idx) |
+	      FIELD_PREP(I40E_PFINT_DYN_CTLN_INTERVAL_MASK, interval);
+
+	/* 3. Enforce software interrupt trigger if requested
+	 *    (These software interrupts rate is limited by ITR2 that is
+	 *     set to 20K interrupts per second)
+	 */
+	if (force_swint)
+		val |= I40E_PFINT_DYN_CTLN_SWINT_TRIG_MASK |
+		       I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK |
+		       FIELD_PREP(I40E_PFINT_DYN_CTLN_SW_ITR_INDX_MASK,
+				  I40E_SW_ITR);
 
 	return val;
 }
 
-/* a small macro to shorten up some long lines */
-#define INTREG I40E_PFINT_DYN_CTLN
-
 /* The act of updating the ITR will cause it to immediately trigger. In order
  * to prevent this from throwing off adaptive update statistics we defer the
  * update so that it can only happen so often. So after either Tx or Rx are
@@ -2679,8 +2704,10 @@ static inline u32 i40e_buildreg_itr(const int type, u16 itr)
 static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
 					  struct i40e_q_vector *q_vector)
 {
+	enum i40e_dyn_idx itr_idx = I40E_ITR_NONE;
 	struct i40e_hw *hw = &vsi->back->hw;
-	u32 intval;
+	u16 interval = 0;
+	u32 itr_val;
 
 	/* If we don't have MSIX, then we only need to re-enable icr0 */
 	if (!test_bit(I40E_FLAG_MSIX_ENA, vsi->back->flags)) {
@@ -2702,8 +2729,8 @@ static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
 	 */
 	if (q_vector->rx.target_itr < q_vector->rx.current_itr) {
 		/* Rx ITR needs to be reduced, this is highest priority */
-		intval = i40e_buildreg_itr(I40E_RX_ITR,
-					   q_vector->rx.target_itr);
+		itr_idx = I40E_RX_ITR;
+		interval = q_vector->rx.target_itr;
 		q_vector->rx.current_itr = q_vector->rx.target_itr;
 		q_vector->itr_countdown = ITR_COUNTDOWN_START;
 	} else if ((q_vector->tx.target_itr < q_vector->tx.current_itr) ||
@@ -2712,25 +2739,36 @@ static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
 		/* Tx ITR needs to be reduced, this is second priority
 		 * Tx ITR needs to be increased more than Rx, fourth priority
 		 */
-		intval = i40e_buildreg_itr(I40E_TX_ITR,
-					   q_vector->tx.target_itr);
+		itr_idx = I40E_TX_ITR;
+		interval = q_vector->tx.target_itr;
 		q_vector->tx.current_itr = q_vector->tx.target_itr;
 		q_vector->itr_countdown = ITR_COUNTDOWN_START;
 	} else if (q_vector->rx.current_itr != q_vector->rx.target_itr) {
 		/* Rx ITR needs to be increased, third priority */
-		intval = i40e_buildreg_itr(I40E_RX_ITR,
-					   q_vector->rx.target_itr);
+		itr_idx = I40E_RX_ITR;
+		interval = q_vector->rx.target_itr;
 		q_vector->rx.current_itr = q_vector->rx.target_itr;
 		q_vector->itr_countdown = ITR_COUNTDOWN_START;
 	} else {
 		/* No ITR update, lowest priority */
-		intval = i40e_buildreg_itr(I40E_ITR_NONE, 0);
 		if (q_vector->itr_countdown)
 			q_vector->itr_countdown--;
 	}
 
-	if (!test_bit(__I40E_VSI_DOWN, vsi->state))
-		wr32(hw, INTREG(q_vector->reg_idx), intval);
+	/* Do not update interrupt control register if VSI is down */
+	if (test_bit(__I40E_VSI_DOWN, vsi->state))
+		return;
+
+	/* Update ITR interval if necessary and enforce software interrupt
+	 * if we are exiting busy poll.
+	 */
+	if (q_vector->in_busy_poll) {
+		itr_val = i40e_buildreg_itr(itr_idx, interval, true);
+		q_vector->in_busy_poll = false;
+	} else {
+		itr_val = i40e_buildreg_itr(itr_idx, interval, false);
+	}
+	wr32(hw, I40E_PFINT_DYN_CTLN(q_vector->reg_idx), itr_val);
 }
 
 /**
@@ -2845,6 +2883,8 @@ int i40e_napi_poll(struct napi_struct *napi, int budget)
 	 */
 	if (likely(napi_complete_done(napi, work_done)))
 		i40e_update_enable_itr(vsi, q_vector);
+	else
+		q_vector->in_busy_poll = true;
 
 	return min(work_done, budget - 1);
 }
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index abf15067eb5d..2cdc7de6301c 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -68,6 +68,7 @@ enum i40e_dyn_idx {
 /* these are indexes into ITRN registers */
 #define I40E_RX_ITR    I40E_IDX_ITR0
 #define I40E_TX_ITR    I40E_IDX_ITR1
+#define I40E_SW_ITR    I40E_IDX_ITR2
 
 /* Supported RSS offloads */
 #define I40E_DEFAULT_RSS_HENA ( \
-- 
2.41.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH net 2/3] i40e: fix i40e_count_filters() to count only active/new filters
  2024-03-26 16:23 [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) Tony Nguyen
  2024-03-26 16:23 ` [PATCH net 1/3] i40e: Enforce software interrupt during busy-poll exit Tony Nguyen
@ 2024-03-26 16:23 ` Tony Nguyen
  2024-03-26 16:23 ` [PATCH net 3/3] i40e: fix vf may be used uninitialized in this function warning Tony Nguyen
  2024-03-29 19:20 ` [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) patchwork-bot+netdevbpf
  3 siblings, 0 replies; 5+ messages in thread
From: Tony Nguyen @ 2024-03-26 16:23 UTC (permalink / raw)
  To: davem, kuba, pabeni, edumazet, netdev
  Cc: Aleksandr Loktionov, anthony.l.nguyen, Arkadiusz Kubalewski,
	Paul Menzel, Rafal Romanowski

From: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

The bug usually affects untrusted VFs, because they are limited to 18 MACs,
it affects them badly, not letting to create MAC all filters.
Not stable to reproduce, it happens when VF user creates MAC filters
when other MACVLAN operations are happened in parallel.
But consequence is that VF can't receive desired traffic.

Fix counter to be bumped only for new or active filters.

Fixes: 621650cabee5 ("i40e: Refactoring VF MAC filters counting to make more reliable")
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 6576a0081093..48b9ddb2b1b3 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -1253,8 +1253,11 @@ int i40e_count_filters(struct i40e_vsi *vsi)
 	int bkt;
 	int cnt = 0;
 
-	hash_for_each_safe(vsi->mac_filter_hash, bkt, h, f, hlist)
-		++cnt;
+	hash_for_each_safe(vsi->mac_filter_hash, bkt, h, f, hlist) {
+		if (f->state == I40E_FILTER_NEW ||
+		    f->state == I40E_FILTER_ACTIVE)
+			++cnt;
+	}
 
 	return cnt;
 }
-- 
2.41.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH net 3/3] i40e: fix vf may be used uninitialized in this function warning
  2024-03-26 16:23 [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) Tony Nguyen
  2024-03-26 16:23 ` [PATCH net 1/3] i40e: Enforce software interrupt during busy-poll exit Tony Nguyen
  2024-03-26 16:23 ` [PATCH net 2/3] i40e: fix i40e_count_filters() to count only active/new filters Tony Nguyen
@ 2024-03-26 16:23 ` Tony Nguyen
  2024-03-29 19:20 ` [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) patchwork-bot+netdevbpf
  3 siblings, 0 replies; 5+ messages in thread
From: Tony Nguyen @ 2024-03-26 16:23 UTC (permalink / raw)
  To: davem, kuba, pabeni, edumazet, netdev
  Cc: Aleksandr Loktionov, anthony.l.nguyen, Arkadiusz Kubalewski,
	Przemek Kitszel, Paul Menzel, Rafal Romanowski

From: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

To fix the regression introduced by commit 52424f974bc5, which causes
servers hang in very hard to reproduce conditions with resets races.
Using two sources for the information is the root cause.
In this function before the fix bumping v didn't mean bumping vf
pointer. But the code used this variables interchangeably, so stale vf
could point to different/not intended vf.

Remove redundant "v" variable and iterate via single VF pointer across
whole function instead to guarantee VF pointer validity.

Fixes: 52424f974bc5 ("i40e: Fix VF hang when reset is triggered on another VF")
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 .../ethernet/intel/i40e/i40e_virtchnl_pf.c    | 34 +++++++++----------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 83a34e98bdc7..4c13f78af675 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -1624,8 +1624,8 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 {
 	struct i40e_hw *hw = &pf->hw;
 	struct i40e_vf *vf;
-	int i, v;
 	u32 reg;
+	int i;
 
 	/* If we don't have any VFs, then there is nothing to reset */
 	if (!pf->num_alloc_vfs)
@@ -1636,11 +1636,10 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 		return false;
 
 	/* Begin reset on all VFs at once */
-	for (v = 0; v < pf->num_alloc_vfs; v++) {
-		vf = &pf->vf[v];
+	for (vf = &pf->vf[0]; vf < &pf->vf[pf->num_alloc_vfs]; ++vf) {
 		/* If VF is being reset no need to trigger reset again */
 		if (!test_bit(I40E_VF_STATE_RESETTING, &vf->vf_states))
-			i40e_trigger_vf_reset(&pf->vf[v], flr);
+			i40e_trigger_vf_reset(vf, flr);
 	}
 
 	/* HW requires some time to make sure it can flush the FIFO for a VF
@@ -1649,14 +1648,13 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 	 * the VFs using a simple iterator that increments once that VF has
 	 * finished resetting.
 	 */
-	for (i = 0, v = 0; i < 10 && v < pf->num_alloc_vfs; i++) {
+	for (i = 0, vf = &pf->vf[0]; i < 10 && vf < &pf->vf[pf->num_alloc_vfs]; ++i) {
 		usleep_range(10000, 20000);
 
 		/* Check each VF in sequence, beginning with the VF to fail
 		 * the previous check.
 		 */
-		while (v < pf->num_alloc_vfs) {
-			vf = &pf->vf[v];
+		while (vf < &pf->vf[pf->num_alloc_vfs]) {
 			if (!test_bit(I40E_VF_STATE_RESETTING, &vf->vf_states)) {
 				reg = rd32(hw, I40E_VPGEN_VFRSTAT(vf->vf_id));
 				if (!(reg & I40E_VPGEN_VFRSTAT_VFRD_MASK))
@@ -1666,7 +1664,7 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 			/* If the current VF has finished resetting, move on
 			 * to the next VF in sequence.
 			 */
-			v++;
+			++vf;
 		}
 	}
 
@@ -1676,39 +1674,39 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 	/* Display a warning if at least one VF didn't manage to reset in
 	 * time, but continue on with the operation.
 	 */
-	if (v < pf->num_alloc_vfs)
+	if (vf < &pf->vf[pf->num_alloc_vfs])
 		dev_err(&pf->pdev->dev, "VF reset check timeout on VF %d\n",
-			pf->vf[v].vf_id);
+			vf->vf_id);
 	usleep_range(10000, 20000);
 
 	/* Begin disabling all the rings associated with VFs, but do not wait
 	 * between each VF.
 	 */
-	for (v = 0; v < pf->num_alloc_vfs; v++) {
+	for (vf = &pf->vf[0]; vf < &pf->vf[pf->num_alloc_vfs]; ++vf) {
 		/* On initial reset, we don't have any queues to disable */
-		if (pf->vf[v].lan_vsi_idx == 0)
+		if (vf->lan_vsi_idx == 0)
 			continue;
 
 		/* If VF is reset in another thread just continue */
 		if (test_bit(I40E_VF_STATE_RESETTING, &vf->vf_states))
 			continue;
 
-		i40e_vsi_stop_rings_no_wait(pf->vsi[pf->vf[v].lan_vsi_idx]);
+		i40e_vsi_stop_rings_no_wait(pf->vsi[vf->lan_vsi_idx]);
 	}
 
 	/* Now that we've notified HW to disable all of the VF rings, wait
 	 * until they finish.
 	 */
-	for (v = 0; v < pf->num_alloc_vfs; v++) {
+	for (vf = &pf->vf[0]; vf < &pf->vf[pf->num_alloc_vfs]; ++vf) {
 		/* On initial reset, we don't have any queues to disable */
-		if (pf->vf[v].lan_vsi_idx == 0)
+		if (vf->lan_vsi_idx == 0)
 			continue;
 
 		/* If VF is reset in another thread just continue */
 		if (test_bit(I40E_VF_STATE_RESETTING, &vf->vf_states))
 			continue;
 
-		i40e_vsi_wait_queues_disabled(pf->vsi[pf->vf[v].lan_vsi_idx]);
+		i40e_vsi_wait_queues_disabled(pf->vsi[vf->lan_vsi_idx]);
 	}
 
 	/* Hw may need up to 50ms to finish disabling the RX queues. We
@@ -1717,12 +1715,12 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 	mdelay(50);
 
 	/* Finish the reset on each VF */
-	for (v = 0; v < pf->num_alloc_vfs; v++) {
+	for (vf = &pf->vf[0]; vf < &pf->vf[pf->num_alloc_vfs]; ++vf) {
 		/* If VF is reset in another thread just continue */
 		if (test_bit(I40E_VF_STATE_RESETTING, &vf->vf_states))
 			continue;
 
-		i40e_cleanup_reset_vf(&pf->vf[v]);
+		i40e_cleanup_reset_vf(vf);
 	}
 
 	i40e_flush(hw);
-- 
2.41.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e)
  2024-03-26 16:23 [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) Tony Nguyen
                   ` (2 preceding siblings ...)
  2024-03-26 16:23 ` [PATCH net 3/3] i40e: fix vf may be used uninitialized in this function warning Tony Nguyen
@ 2024-03-29 19:20 ` patchwork-bot+netdevbpf
  3 siblings, 0 replies; 5+ messages in thread
From: patchwork-bot+netdevbpf @ 2024-03-29 19:20 UTC (permalink / raw)
  To: Tony Nguyen; +Cc: davem, kuba, pabeni, edumazet, netdev

Hello:

This series was applied to netdev/net.git (main)
by Tony Nguyen <anthony.l.nguyen@intel.com>:

On Tue, 26 Mar 2024 09:23:41 -0700 you wrote:
> This series contains updates to i40e driver only.
> 
> Ivan Vecera resolves an issue where descriptors could be missed when
> exiting busy poll.
> 
> Aleksandr corrects counting of MAC filters to only include new or active
> filters and resolves possible use of incorrect/stale 'vf' variable.
> 
> [...]

Here is the summary with links:
  - [net,1/3] i40e: Enforce software interrupt during busy-poll exit
    https://git.kernel.org/netdev/net/c/ea558de7238b
  - [net,2/3] i40e: fix i40e_count_filters() to count only active/new filters
    https://git.kernel.org/netdev/net/c/eb58c598ce45
  - [net,3/3] i40e: fix vf may be used uninitialized in this function warning
    https://git.kernel.org/netdev/net/c/f37c4eac99c2

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2024-03-29 19:20 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-03-26 16:23 [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) Tony Nguyen
2024-03-26 16:23 ` [PATCH net 1/3] i40e: Enforce software interrupt during busy-poll exit Tony Nguyen
2024-03-26 16:23 ` [PATCH net 2/3] i40e: fix i40e_count_filters() to count only active/new filters Tony Nguyen
2024-03-26 16:23 ` [PATCH net 3/3] i40e: fix vf may be used uninitialized in this function warning Tony Nguyen
2024-03-29 19:20 ` [PATCH net 0/3][pull request] Intel Wired LAN Driver Updates 2024-03-26 (i40e) patchwork-bot+netdevbpf

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