From fd867d51f889aec11cca235ebb008578780d052d Mon Sep 17 00:00:00 2001 From: Jarod Wilson Date: Mon, 2 Nov 2015 21:55:59 -0500 Subject: net/core: generic support for disabling netdev features down stack There are some netdev features, which when disabled on an upper device, such as a bonding master or a bridge, must be disabled and cannot be re-enabled on underlying devices. This is a rework of an earlier more heavy-handed appraoch, which simply disables and prevents re-enabling of netdev features listed in a new define in include/net/netdev_features.h, NETIF_F_UPPER_DISABLES. Any upper device that disables a flag in that feature mask, the disabling will propagate down the stack, and any lower device that has any upper device with one of those flags disabled should not be able to enable said flag. Initially, only LRO is included for proof of concept, and because this code effectively does the same thing as dev_disable_lro(), though it will also activate from the ethtool path, which was one of the goals here. [root@dell-per730-01 ~]# ethtool -k bond0 |grep large large-receive-offload: on [root@dell-per730-01 ~]# ethtool -k p5p1 |grep large large-receive-offload: on [root@dell-per730-01 ~]# ethtool -K bond0 lro off [root@dell-per730-01 ~]# ethtool -k bond0 |grep large large-receive-offload: off [root@dell-per730-01 ~]# ethtool -k p5p1 |grep large large-receive-offload: off dmesg dump: [ 1033.277986] bond0: Disabling feature 0x0000000000008000 on lower dev p5p2. [ 1034.067949] bnx2x 0000:06:00.1 p5p2: using MSI-X IRQs: sp 74 fp[0] 76 ... fp[7] 83 [ 1034.753612] bond0: Disabling feature 0x0000000000008000 on lower dev p5p1. [ 1035.591019] bnx2x 0000:06:00.0 p5p1: using MSI-X IRQs: sp 62 fp[0] 64 ... fp[7] 71 This has been successfully tested with bnx2x, qlcnic and netxen network cards as slaves in a bond interface. Turning LRO on or off on the master also turns it on or off on each of the slaves, new slaves are added with LRO in the same state as the master, and LRO can't be toggled on the slaves. Also, this should largely remove the need for dev_disable_lro(), and most, if not all, of its call sites can be replaced by simply making sure NETIF_F_LRO isn't included in the relevant device's feature flags. Note that this patch is driven by bug reports from users saying it was confusing that bonds and slaves had different settings for the same features, and while it won't be 100% in sync if a lower device doesn't support a feature like LRO, I think this is a good step in the right direction. CC: "David S. Miller" CC: Eric Dumazet CC: Jay Vosburgh CC: Veaceslav Falico CC: Andy Gospodarek CC: Jiri Pirko CC: Nikolay Aleksandrov CC: Michal Kubecek CC: Alexander Duyck CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson Signed-off-by: David S. Miller --- include/linux/netdev_features.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/linux/netdev_features.h') diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index 9672781c593d..0f5837a9b1ba 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -125,6 +125,11 @@ enum { #define NETIF_F_HW_L2FW_DOFFLOAD __NETIF_F(HW_L2FW_DOFFLOAD) #define NETIF_F_BUSY_POLL __NETIF_F(BUSY_POLL) +#define for_each_netdev_feature(mask_addr, feature) \ + int bit; \ + for_each_set_bit(bit, (unsigned long *)mask_addr, NETDEV_FEATURE_COUNT) \ + feature = __NETIF_F_BIT(bit); + /* Features valid for ethtool to change */ /* = all defined minus driver/device-class-related */ #define NETIF_F_NEVER_CHANGE (NETIF_F_VLAN_CHALLENGED | \ @@ -167,6 +172,12 @@ enum { */ #define NETIF_F_ALL_FOR_ALL (NETIF_F_NOCACHE_COPY | NETIF_F_FSO) +/* + * If upper/master device has these features disabled, they must be disabled + * on all lower/slave devices as well. + */ +#define NETIF_F_UPPER_DISABLES NETIF_F_LRO + /* changeable features with no special hardware requirements */ #define NETIF_F_SOFT_FEATURES (NETIF_F_GSO | NETIF_F_GRO) -- cgit v1.2.3 From 5ba3f7d61a3a9e6d94462b207d302931b53d8c61 Mon Sep 17 00:00:00 2001 From: Jarod Wilson Date: Tue, 3 Nov 2015 10:15:59 -0500 Subject: net/core: fix for_each_netdev_feature As pointed out by Nikolay and further explained by Geert, the initial for_each_netdev_feature macro was broken, as feature would get set outside of the block of code it was intended to run in, thus only ever working for the first feature bit in the mask. While less pretty this way, this is tested and confirmed functional with multiple feature bits set in NETIF_F_UPPER_DISABLES. [root@dell-per730-01 ~]# ethtool -K bond0 lro off ... [ 242.761394] bond0: Disabling feature 0x0000000000008000 on lower dev p5p2. [ 243.552178] bnx2x 0000:06:00.1 p5p2: using MSI-X IRQs: sp 74 fp[0] 76 ... fp[7] 83 [ 244.353978] bond0: Disabling feature 0x0000000000008000 on lower dev p5p1. [ 245.147420] bnx2x 0000:06:00.0 p5p1: using MSI-X IRQs: sp 62 fp[0] 64 ... fp[7] 71 [root@dell-per730-01 ~]# ethtool -K bond0 gro off ... [ 251.925645] bond0: Disabling feature 0x0000000000004000 on lower dev p5p2. [ 252.713693] bnx2x 0000:06:00.1 p5p2: using MSI-X IRQs: sp 74 fp[0] 76 ... fp[7] 83 [ 253.499085] bond0: Disabling feature 0x0000000000004000 on lower dev p5p1. [ 254.290922] bnx2x 0000:06:00.0 p5p1: using MSI-X IRQs: sp 62 fp[0] 64 ... fp[7] 71 Fixes: fd867d51f ("net/core: generic support for disabling netdev features down stack") CC: "David S. Miller" CC: Eric Dumazet CC: Jay Vosburgh CC: Veaceslav Falico CC: Andy Gospodarek CC: Jiri Pirko CC: Nikolay Aleksandrov CC: Michal Kubecek CC: Alexander Duyck CC: Geert Uytterhoeven CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- include/linux/netdev_features.h | 6 ++---- net/core/dev.c | 8 ++++++-- 2 files changed, 8 insertions(+), 6 deletions(-) (limited to 'include/linux/netdev_features.h') diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index 0f5837a9b1ba..f0d87347df19 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -125,10 +125,8 @@ enum { #define NETIF_F_HW_L2FW_DOFFLOAD __NETIF_F(HW_L2FW_DOFFLOAD) #define NETIF_F_BUSY_POLL __NETIF_F(BUSY_POLL) -#define for_each_netdev_feature(mask_addr, feature) \ - int bit; \ - for_each_set_bit(bit, (unsigned long *)mask_addr, NETDEV_FEATURE_COUNT) \ - feature = __NETIF_F_BIT(bit); +#define for_each_netdev_feature(mask_addr, bit) \ + for_each_set_bit(bit, (unsigned long *)mask_addr, NETDEV_FEATURE_COUNT) /* Features valid for ethtool to change */ /* = all defined minus driver/device-class-related */ diff --git a/net/core/dev.c b/net/core/dev.c index c4d2b430788d..8ce3f74cd6b9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6293,8 +6293,10 @@ static netdev_features_t netdev_sync_upper_features(struct net_device *lower, { netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES; netdev_features_t feature; + int feature_bit; - for_each_netdev_feature(&upper_disables, feature) { + for_each_netdev_feature(&upper_disables, feature_bit) { + feature = __NETIF_F_BIT(feature_bit); if (!(upper->wanted_features & feature) && (features & feature)) { netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n", @@ -6311,8 +6313,10 @@ static void netdev_sync_lower_features(struct net_device *upper, { netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES; netdev_features_t feature; + int feature_bit; - for_each_netdev_feature(&upper_disables, feature) { + for_each_netdev_feature(&upper_disables, feature_bit) { + feature = __NETIF_F_BIT(feature_bit); if (!(features & feature) && (lower->features & feature)) { netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n", &feature, lower->name); -- cgit v1.2.3