A bug occurs because a safety check guarding AF_XDP-related queues in
ethnl_set_channels(), does not trigger. This happens, because kernel and
ice driver interpret the ethtool command differently.
How the bug occurs:
1. ethtool -l <IFNAME> -> combined: 40
2. Attach AF_XDP to queue 30
3. ethtool -L <IFNAME> rx 15 tx 15
combined number is not specified, so command becomes {rx_count = 15,
tx_count = 15, combined_count = 40}.
4. ethnl_set_channels checks, if there are any AF_XDP of queues from the
new (combined_count + rx_count) to the old one, so from 55 to 40, check
does not trigger.
5. ice interprets `rx 15 tx 15` as 15 combined channels and deletes the
queue that AF_XDP is attached to.
Interpret the command in a way that is more consistent with ethtool
manual [0] (--show-channels and --set-channels).
Considering that in the ice driver only the difference between RX and TX
queues forms dedicated channels, change the correct way to set number of
channels to:
ethtool -L <IFNAME> combined 10 /* For symmetric queues */
ethtool -L <IFNAME> combined 8 tx 2 rx 0 /* For asymmetric queues */
[0] https://man7.org/linux/man-pages/man8/ethtool.8.html
Fixes: 87324e747fde ("ice: Implement ethtool ops for channels")
Reviewed-by: Michal Swiatkowski <[email protected]>
Signed-off-by: Larysa Zaremba <[email protected]>
---
drivers/net/ethernet/intel/ice/ice_ethtool.c | 22 ++++++--------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index 78b833b3e1d7..d91f41f61bce 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
@@ -3593,7 +3593,6 @@ static int ice_set_channels(struct net_device *dev, struct ethtool_channels *ch)
struct ice_pf *pf = vsi->back;
int new_rx = 0, new_tx = 0;
bool locked = false;
- u32 curr_combined;
int ret = 0;
/* do not support changing channels in Safe Mode */
@@ -3615,22 +3614,13 @@ static int ice_set_channels(struct net_device *dev, struct ethtool_channels *ch)
return -EOPNOTSUPP;
}
- curr_combined = ice_get_combined_cnt(vsi);
+ if (!ch->combined_count) {
+ netdev_err(dev, "Please specify at least 1 combined channel\n");
+ return -EINVAL;
+ }
- /* these checks are for cases where user didn't specify a particular
- * value on cmd line but we get non-zero value anyway via
- * get_channels(); look at ethtool.c in ethtool repository (the user
- * space part), particularly, do_schannels() routine
- */
- if (ch->rx_count == vsi->num_rxq - curr_combined)
- ch->rx_count = 0;
- if (ch->tx_count == vsi->num_txq - curr_combined)
- ch->tx_count = 0;
- if (ch->combined_count == curr_combined)
- ch->combined_count = 0;
-
- if (!(ch->combined_count || (ch->rx_count && ch->tx_count))) {
- netdev_err(dev, "Please specify at least 1 Rx and 1 Tx channel\n");
+ if (ch->rx_count && ch->tx_count) {
+ netdev_err(dev, "Dedicated RX or TX channels cannot be used simultaneously\n");
return -EINVAL;
}
--
2.43.0
>-----Original Message-----
>From: Intel-wired-lan <[email protected]> On Behalf Of
>Zaremba, Larysa
>Sent: Thursday, April 18, 2024 3:29 PM
>To: Nguyen, Anthony L <[email protected]>; intel-wired-
>[email protected]; [email protected]; [email protected]
>Cc: Fijalkowski, Maciej <[email protected]>; Tantilov, Emil S
><[email protected]>; Zaremba, Larysa <[email protected]>;
>Czapnik, Lukasz <[email protected]>; Eric Dumazet
><[email protected]>; Brady, Alan <[email protected]>; Michal
>Swiatkowski <[email protected]>; Jakub Kicinski
><[email protected]>; Paolo Abeni <[email protected]>; David S. Miller
><[email protected]>
>Subject: [Intel-wired-lan] [PATCH RESEND iwl-net] ice: Interpret .set_channels()
>input differently
>
>A bug occurs because a safety check guarding AF_XDP-related queues in
>ethnl_set_channels(), does not trigger. This happens, because kernel and ice
>driver interpret the ethtool command differently.
>
>How the bug occurs:
>1. ethtool -l <IFNAME> -> combined: 40
>2. Attach AF_XDP to queue 30
>3. ethtool -L <IFNAME> rx 15 tx 15
> combined number is not specified, so command becomes {rx_count = 15,
> tx_count = 15, combined_count = 40}.
>4. ethnl_set_channels checks, if there are any AF_XDP of queues from the
> new (combined_count + rx_count) to the old one, so from 55 to 40, check
> does not trigger.
>5. ice interprets `rx 15 tx 15` as 15 combined channels and deletes the
> queue that AF_XDP is attached to.
>
>Interpret the command in a way that is more consistent with ethtool manual
>[0] (--show-channels and --set-channels).
>
>Considering that in the ice driver only the difference between RX and TX queues
>forms dedicated channels, change the correct way to set number of channels
>to:
>
>ethtool -L <IFNAME> combined 10 /* For symmetric queues */ ethtool -L
><IFNAME> combined 8 tx 2 rx 0 /* For asymmetric queues */
>
>[0] https://man7.org/linux/man-pages/man8/ethtool.8.html
>
>Fixes: 87324e747fde ("ice: Implement ethtool ops for channels")
>Reviewed-by: Michal Swiatkowski <[email protected]>
>Signed-off-by: Larysa Zaremba <[email protected]>
>---
> drivers/net/ethernet/intel/ice/ice_ethtool.c | 22 ++++++--------------
> 1 file changed, 6 insertions(+), 16 deletions(-)
>
Tested-by: Chandan Kumar Rout <[email protected]> (A Contingent Worker at Intel)
> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf Of Larysa Zaremba
> Sent: Thursday, April 18, 2024 3:29 PM
> To: Nguyen, Anthony L <[email protected]>; [email protected]; [email protected]; [email protected]
> Cc: Fijalkowski, Maciej <[email protected]>; Tantilov, Emil S <[email protected]>; Zaremba, Larysa <[email protected]>; Czapnik, Lukasz <[email protected]>; Eric Dumazet <[email protected]>; Brady, Alan <[email protected]>; Michal Swiatkowski <[email protected]>; Jakub Kicinski <[email protected]>; Paolo Abeni <[email protected]>; David S. Miller <[email protected]>
> Subject: [Intel-wired-lan] [PATCH RESEND iwl-net] ice: Interpret .set_channels() input differently
>
> A bug occurs because a safety check guarding AF_XDP-related queues in ethnl_set_channels(), does not trigger. This happens, because kernel and ice driver interpret the ethtool command differently.
>
> How the bug occurs:
> 1. ethtool -l <IFNAME> -> combined: 40
> 2. Attach AF_XDP to queue 30
> 3. ethtool -L <IFNAME> rx 15 tx 15
> combined number is not specified, so command becomes {rx_count = 15,
> tx_count = 15, combined_count = 40}.
> 4. ethnl_set_channels checks, if there are any AF_XDP of queues from the
> new (combined_count + rx_count) to the old one, so from 55 to 40, check
> does not trigger.
> 5. ice interprets `rx 15 tx 15` as 15 combined channels and deletes the
> queue that AF_XDP is attached to.
>
> Interpret the command in a way that is more consistent with ethtool manual [0] (--show-channels and --set-channels).
>
> Considering that in the ice driver only the difference between RX and TX queues forms dedicated channels, change the correct way to set number of channels to:
>
> ethtool -L <IFNAME> combined 10 /* For symmetric queues */ ethtool -L <IFNAME> combined 8 tx 2 rx 0 /* For asymmetric queues */
>
> [0] https://man7.org/linux/man-pages/man8/ethtool.8.html
>
> Fixes: 87324e747fde ("ice: Implement ethtool ops for channels")
> Reviewed-by: Michal Swiatkowski <[email protected]>
> Signed-off-by: Larysa Zaremba <[email protected]>
> ---
> drivers/net/ethernet/intel/ice/ice_ethtool.c | 22 ++++++--------------
> 1 file changed, 6 insertions(+), 16 deletions(-)
>
Tested-by: Pucha Himasekhar Reddy <[email protected]> (A Contingent worker at Intel)