| Message ID | 20240416125856.1263314-1-larysa.zaremba@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [iwl-net] ice: Interpret .set_channels() input differently | expand |
On Tue, Apr 16, 2024 at 02:58:54PM +0200, Larysa Zaremba wrote: > 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 */ Makes sense for usage above: Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Nonetheless I still think core should not allow user to shoot himself to foot, but let's keep it as a separate thing. Thanks! > > [0] https://man7.org/linux/man-pages/man8/ethtool.8.html > > Fixes: 87324e747fde ("ice: Implement ethtool ops for channels") > Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com> > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > --- > 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 >
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; }
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 <michal.swiatkowski@linux.intel.com> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> --- drivers/net/ethernet/intel/ice/ice_ethtool.c | 22 ++++++-------------- 1 file changed, 6 insertions(+), 16 deletions(-)