| Message ID | 20201021115915.8286-1-mst@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3] Revert "virtio-net: ethtool configurable RXCSUM" | expand |
On Wed, Oct 21, 2020 at 8:00 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > This reverts commit 3618ad2a7c0e78e4258386394d5d5f92a3dbccf8. > > When control vq is not negotiated, that commit causes a crash: > > [ 72.229171] kernel BUG at drivers/net/virtio_net.c:1667! > [ 72.230266] invalid opcode: 0000 [#1] PREEMPT SMP > [ 72.231172] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc8-02934-g3618ad2a7c0e7 #1 > [ 72.231172] EIP: virtnet_send_command+0x120/0x140 > [ 72.231172] Code: 00 0f 94 c0 8b 7d f0 65 33 3d 14 00 00 00 75 1c 8d 65 f4 5b 5e 5f 5d c3 66 90 be 01 00 00 00 e9 6e ff ff ff 8d b6 00 > +00 00 00 <0f> 0b e8 d9 bb 82 00 eb 17 8d b4 26 00 00 00 00 8d b4 26 00 00 00 > [ 72.231172] EAX: 0000000d EBX: f72895c0 ECX: 00000017 EDX: 00000011 > [ 72.231172] ESI: f7197800 EDI: ed69bd00 EBP: ed69bcf4 ESP: ed69bc98 > [ 72.231172] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010246 > [ 72.231172] CR0: 80050033 CR2: 00000000 CR3: 02c84000 CR4: 000406f0 > [ 72.231172] Call Trace: > [ 72.231172] ? __virt_addr_valid+0x45/0x60 > [ 72.231172] ? ___cache_free+0x51f/0x760 > [ 72.231172] ? kobject_uevent_env+0xf4/0x560 > [ 72.231172] virtnet_set_guest_offloads+0x4d/0x80 > [ 72.231172] virtnet_set_features+0x85/0x120 > [ 72.231172] ? virtnet_set_guest_offloads+0x80/0x80 > [ 72.231172] __netdev_update_features+0x27a/0x8e0 > [ 72.231172] ? kobject_uevent+0xa/0x20 > [ 72.231172] ? netdev_register_kobject+0x12c/0x160 > [ 72.231172] register_netdevice+0x4fe/0x740 > [ 72.231172] register_netdev+0x1c/0x40 > [ 72.231172] virtnet_probe+0x728/0xb60 > [ 72.231172] ? _raw_spin_unlock+0x1d/0x40 > [ 72.231172] ? virtio_vdpa_get_status+0x1c/0x20 > [ 72.231172] virtio_dev_probe+0x1c6/0x271 > [ 72.231172] really_probe+0x195/0x2e0 > [ 72.231172] driver_probe_device+0x26/0x60 > [ 72.231172] device_driver_attach+0x49/0x60 > [ 72.231172] __driver_attach+0x46/0xc0 > [ 72.231172] ? device_driver_attach+0x60/0x60 > [ 72.231172] bus_add_driver+0x197/0x1c0 > [ 72.231172] driver_register+0x66/0xc0 > [ 72.231172] register_virtio_driver+0x1b/0x40 > [ 72.231172] virtio_net_driver_init+0x61/0x86 > [ 72.231172] ? veth_init+0x14/0x14 > [ 72.231172] do_one_initcall+0x76/0x2e4 > [ 72.231172] ? rdinit_setup+0x2a/0x2a > [ 72.231172] do_initcalls+0xb2/0xd5 > [ 72.231172] kernel_init_freeable+0x14f/0x179 > [ 72.231172] ? rest_init+0x100/0x100 > [ 72.231172] kernel_init+0xd/0xe0 > [ 72.231172] ret_from_fork+0x1c/0x30 > [ 72.231172] Modules linked in: > [ 72.269563] ---[ end trace a6ebc4afea0e6cb1 ]--- > > The reason is that virtnet_set_features now calls virtnet_set_guest_offloads > unconditionally, it used to only call it when there is something > to configure. Right. The fix might be to make the call to virtnet_set_guest_offloads conditional again - err = virtnet_set_guest_offloads(vi, offloads); - if (err) - return err; + if (offloads ^ vi->guest_offloads) { + err = virtnet_set_guest_offloads(vi, offloads); + if (err) + return err; + } Whether the two features in virtnet_set_features are configurable at all depends on whether they are part of dev->hw_features, which is conditional on guest offload support: if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { dev->hw_features |= NETIF_F_RXCSUM; dev->hw_features |= NETIF_F_LRO; } so I had not expected virtnet_set_features to get called at all unless this was enabled. Clearly an incorrect assumption. The conservative solution is a full revert and resubmitting a correct new patch for net-next. Thanks for preparing the revert, sorry for the breakage. Are you sending it for a third time because of the patchwork quirk? > If device does not have a control vq, everything breaks. > > Looking at this some more, I noticed that it's not really checking the > hardware too much. E.g. > > if ((dev->features ^ features) & NETIF_F_LRO) { > if (features & NETIF_F_LRO) > offloads |= GUEST_OFFLOAD_LRO_MASK & > vi->guest_offloads_capable; > else > offloads &= ~GUEST_OFFLOAD_LRO_MASK; > } > > and > > (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \ > (1ULL << VIRTIO_NET_F_GUEST_ECN) | \ > (1ULL << VIRTIO_NET_F_GUEST_UFO)) > > But there's no guarantee that e.g. VIRTIO_NET_F_GUEST_TSO6 is set. > > If it isn't command should not send it. It only toggles the subset of this mask that is agreed on at probe and at that time stored in guest_offloads_capable. As Jason also mentioned. I think this comment is obsolete. for (i = 0; i < ARRAY_SIZE(guest_offloads); i++) if (virtio_has_feature(vi->vdev, guest_offloads[i])) set_bit(guest_offloads[i], &vi->guest_offloads); vi->guest_offloads_capable = vi->guest_offloads;
On Wed, Oct 21, 2020 at 10:18:20AM -0400, Willem de Bruijn wrote: > On Wed, Oct 21, 2020 at 8:00 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > This reverts commit 3618ad2a7c0e78e4258386394d5d5f92a3dbccf8. > > > > When control vq is not negotiated, that commit causes a crash: > > > > [ 72.229171] kernel BUG at drivers/net/virtio_net.c:1667! > > [ 72.230266] invalid opcode: 0000 [#1] PREEMPT SMP > > [ 72.231172] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc8-02934-g3618ad2a7c0e7 #1 > > [ 72.231172] EIP: virtnet_send_command+0x120/0x140 > > [ 72.231172] Code: 00 0f 94 c0 8b 7d f0 65 33 3d 14 00 00 00 75 1c 8d 65 f4 5b 5e 5f 5d c3 66 90 be 01 00 00 00 e9 6e ff ff ff 8d b6 00 > > +00 00 00 <0f> 0b e8 d9 bb 82 00 eb 17 8d b4 26 00 00 00 00 8d b4 26 00 00 00 > > [ 72.231172] EAX: 0000000d EBX: f72895c0 ECX: 00000017 EDX: 00000011 > > [ 72.231172] ESI: f7197800 EDI: ed69bd00 EBP: ed69bcf4 ESP: ed69bc98 > > [ 72.231172] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010246 > > [ 72.231172] CR0: 80050033 CR2: 00000000 CR3: 02c84000 CR4: 000406f0 > > [ 72.231172] Call Trace: > > [ 72.231172] ? __virt_addr_valid+0x45/0x60 > > [ 72.231172] ? ___cache_free+0x51f/0x760 > > [ 72.231172] ? kobject_uevent_env+0xf4/0x560 > > [ 72.231172] virtnet_set_guest_offloads+0x4d/0x80 > > [ 72.231172] virtnet_set_features+0x85/0x120 > > [ 72.231172] ? virtnet_set_guest_offloads+0x80/0x80 > > [ 72.231172] __netdev_update_features+0x27a/0x8e0 > > [ 72.231172] ? kobject_uevent+0xa/0x20 > > [ 72.231172] ? netdev_register_kobject+0x12c/0x160 > > [ 72.231172] register_netdevice+0x4fe/0x740 > > [ 72.231172] register_netdev+0x1c/0x40 > > [ 72.231172] virtnet_probe+0x728/0xb60 > > [ 72.231172] ? _raw_spin_unlock+0x1d/0x40 > > [ 72.231172] ? virtio_vdpa_get_status+0x1c/0x20 > > [ 72.231172] virtio_dev_probe+0x1c6/0x271 > > [ 72.231172] really_probe+0x195/0x2e0 > > [ 72.231172] driver_probe_device+0x26/0x60 > > [ 72.231172] device_driver_attach+0x49/0x60 > > [ 72.231172] __driver_attach+0x46/0xc0 > > [ 72.231172] ? device_driver_attach+0x60/0x60 > > [ 72.231172] bus_add_driver+0x197/0x1c0 > > [ 72.231172] driver_register+0x66/0xc0 > > [ 72.231172] register_virtio_driver+0x1b/0x40 > > [ 72.231172] virtio_net_driver_init+0x61/0x86 > > [ 72.231172] ? veth_init+0x14/0x14 > > [ 72.231172] do_one_initcall+0x76/0x2e4 > > [ 72.231172] ? rdinit_setup+0x2a/0x2a > > [ 72.231172] do_initcalls+0xb2/0xd5 > > [ 72.231172] kernel_init_freeable+0x14f/0x179 > > [ 72.231172] ? rest_init+0x100/0x100 > > [ 72.231172] kernel_init+0xd/0xe0 > > [ 72.231172] ret_from_fork+0x1c/0x30 > > [ 72.231172] Modules linked in: > > [ 72.269563] ---[ end trace a6ebc4afea0e6cb1 ]--- > > > > The reason is that virtnet_set_features now calls virtnet_set_guest_offloads > > unconditionally, it used to only call it when there is something > > to configure. > > Right. The fix might be to make the call to virtnet_set_guest_offloads > conditional again > > - err = virtnet_set_guest_offloads(vi, offloads); > - if (err) > - return err; > + if (offloads ^ vi->guest_offloads) { > + err = virtnet_set_guest_offloads(vi, offloads); > + if (err) > + return err; > + } > > Whether the two features in virtnet_set_features are configurable at > all depends on whether they are part of dev->hw_features, which is > conditional on guest offload support: > > if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { > dev->hw_features |= NETIF_F_RXCSUM; > dev->hw_features |= NETIF_F_LRO; > } > > so I had not expected virtnet_set_features to get called at all unless > this was enabled. Clearly an incorrect assumption. > > The conservative solution is a full revert and resubmitting a correct > new patch for net-next. Thanks for preparing the revert, sorry for the > breakage. Are you sending it for a third time because of the patchwork > quirk? No - I'm tweaking the commit log each time. > > If device does not have a control vq, everything breaks. > > > > Looking at this some more, I noticed that it's not really checking the > > hardware too much. E.g. > > > > if ((dev->features ^ features) & NETIF_F_LRO) { > > if (features & NETIF_F_LRO) > > offloads |= GUEST_OFFLOAD_LRO_MASK & > > vi->guest_offloads_capable; > > else > > offloads &= ~GUEST_OFFLOAD_LRO_MASK; > > } > > > > and > > > > (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \ > > (1ULL << VIRTIO_NET_F_GUEST_ECN) | \ > > (1ULL << VIRTIO_NET_F_GUEST_UFO)) > > > > But there's no guarantee that e.g. VIRTIO_NET_F_GUEST_TSO6 is set. > > > > If it isn't command should not send it. > > It only toggles the subset of this mask that is agreed on at probe and > at that time stored in guest_offloads_capable. As Jason also > mentioned. I think this comment is obsolete. Hmm I guess you are right. v4 here we come ... > for (i = 0; i < ARRAY_SIZE(guest_offloads); i++) > if (virtio_has_feature(vi->vdev, guest_offloads[i])) > set_bit(guest_offloads[i], &vi->guest_offloads); > vi->guest_offloads_capable = vi->guest_offloads;
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d2d2c4a53cf2..21b71148c532 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -68,8 +68,6 @@ static const unsigned long guest_offloads[] = { (1ULL << VIRTIO_NET_F_GUEST_ECN) | \ (1ULL << VIRTIO_NET_F_GUEST_UFO)) -#define GUEST_OFFLOAD_CSUM_MASK (1ULL << VIRTIO_NET_F_GUEST_CSUM) - struct virtnet_stat_desc { char desc[ETH_GSTRING_LEN]; size_t offset; @@ -2524,48 +2522,29 @@ static int virtnet_get_phys_port_name(struct net_device *dev, char *buf, return 0; } -static netdev_features_t virtnet_fix_features(struct net_device *netdev, - netdev_features_t features) -{ - /* If Rx checksum is disabled, LRO should also be disabled. */ - if (!(features & NETIF_F_RXCSUM)) - features &= ~NETIF_F_LRO; - - return features; -} - static int virtnet_set_features(struct net_device *dev, netdev_features_t features) { struct virtnet_info *vi = netdev_priv(dev); - u64 offloads = vi->guest_offloads; + u64 offloads; int err; - /* Don't allow configuration while XDP is active. */ - if (vi->xdp_queue_pairs) - return -EBUSY; - if ((dev->features ^ features) & NETIF_F_LRO) { + if (vi->xdp_queue_pairs) + return -EBUSY; + if (features & NETIF_F_LRO) - offloads |= GUEST_OFFLOAD_LRO_MASK & - vi->guest_offloads_capable; + offloads = vi->guest_offloads_capable; else - offloads &= ~GUEST_OFFLOAD_LRO_MASK; + offloads = vi->guest_offloads_capable & + ~GUEST_OFFLOAD_LRO_MASK; + + err = virtnet_set_guest_offloads(vi, offloads); + if (err) + return err; + vi->guest_offloads = offloads; } - if ((dev->features ^ features) & NETIF_F_RXCSUM) { - if (features & NETIF_F_RXCSUM) - offloads |= GUEST_OFFLOAD_CSUM_MASK & - vi->guest_offloads_capable; - else - offloads &= ~GUEST_OFFLOAD_CSUM_MASK; - } - - err = virtnet_set_guest_offloads(vi, offloads); - if (err) - return err; - - vi->guest_offloads = offloads; return 0; } @@ -2584,7 +2563,6 @@ static const struct net_device_ops virtnet_netdev = { .ndo_features_check = passthru_features_check, .ndo_get_phys_port_name = virtnet_get_phys_port_name, .ndo_set_features = virtnet_set_features, - .ndo_fix_features = virtnet_fix_features, }; static void virtnet_config_changed_work(struct work_struct *work) @@ -3035,10 +3013,8 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)) dev->features |= NETIF_F_LRO; - if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) { - dev->hw_features |= NETIF_F_RXCSUM; + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) dev->hw_features |= NETIF_F_LRO; - } dev->vlan_features = dev->features;
This reverts commit 3618ad2a7c0e78e4258386394d5d5f92a3dbccf8. When control vq is not negotiated, that commit causes a crash: [ 72.229171] kernel BUG at drivers/net/virtio_net.c:1667! [ 72.230266] invalid opcode: 0000 [#1] PREEMPT SMP [ 72.231172] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc8-02934-g3618ad2a7c0e7 #1 [ 72.231172] EIP: virtnet_send_command+0x120/0x140 [ 72.231172] Code: 00 0f 94 c0 8b 7d f0 65 33 3d 14 00 00 00 75 1c 8d 65 f4 5b 5e 5f 5d c3 66 90 be 01 00 00 00 e9 6e ff ff ff 8d b6 00 +00 00 00 <0f> 0b e8 d9 bb 82 00 eb 17 8d b4 26 00 00 00 00 8d b4 26 00 00 00 [ 72.231172] EAX: 0000000d EBX: f72895c0 ECX: 00000017 EDX: 00000011 [ 72.231172] ESI: f7197800 EDI: ed69bd00 EBP: ed69bcf4 ESP: ed69bc98 [ 72.231172] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010246 [ 72.231172] CR0: 80050033 CR2: 00000000 CR3: 02c84000 CR4: 000406f0 [ 72.231172] Call Trace: [ 72.231172] ? __virt_addr_valid+0x45/0x60 [ 72.231172] ? ___cache_free+0x51f/0x760 [ 72.231172] ? kobject_uevent_env+0xf4/0x560 [ 72.231172] virtnet_set_guest_offloads+0x4d/0x80 [ 72.231172] virtnet_set_features+0x85/0x120 [ 72.231172] ? virtnet_set_guest_offloads+0x80/0x80 [ 72.231172] __netdev_update_features+0x27a/0x8e0 [ 72.231172] ? kobject_uevent+0xa/0x20 [ 72.231172] ? netdev_register_kobject+0x12c/0x160 [ 72.231172] register_netdevice+0x4fe/0x740 [ 72.231172] register_netdev+0x1c/0x40 [ 72.231172] virtnet_probe+0x728/0xb60 [ 72.231172] ? _raw_spin_unlock+0x1d/0x40 [ 72.231172] ? virtio_vdpa_get_status+0x1c/0x20 [ 72.231172] virtio_dev_probe+0x1c6/0x271 [ 72.231172] really_probe+0x195/0x2e0 [ 72.231172] driver_probe_device+0x26/0x60 [ 72.231172] device_driver_attach+0x49/0x60 [ 72.231172] __driver_attach+0x46/0xc0 [ 72.231172] ? device_driver_attach+0x60/0x60 [ 72.231172] bus_add_driver+0x197/0x1c0 [ 72.231172] driver_register+0x66/0xc0 [ 72.231172] register_virtio_driver+0x1b/0x40 [ 72.231172] virtio_net_driver_init+0x61/0x86 [ 72.231172] ? veth_init+0x14/0x14 [ 72.231172] do_one_initcall+0x76/0x2e4 [ 72.231172] ? rdinit_setup+0x2a/0x2a [ 72.231172] do_initcalls+0xb2/0xd5 [ 72.231172] kernel_init_freeable+0x14f/0x179 [ 72.231172] ? rest_init+0x100/0x100 [ 72.231172] kernel_init+0xd/0xe0 [ 72.231172] ret_from_fork+0x1c/0x30 [ 72.231172] Modules linked in: [ 72.269563] ---[ end trace a6ebc4afea0e6cb1 ]--- The reason is that virtnet_set_features now calls virtnet_set_guest_offloads unconditionally, it used to only call it when there is something to configure. If device does not have a control vq, everything breaks. Looking at this some more, I noticed that it's not really checking the hardware too much. E.g. if ((dev->features ^ features) & NETIF_F_LRO) { if (features & NETIF_F_LRO) offloads |= GUEST_OFFLOAD_LRO_MASK & vi->guest_offloads_capable; else offloads &= ~GUEST_OFFLOAD_LRO_MASK; } and (1ULL << VIRTIO_NET_F_GUEST_TSO6) | \ (1ULL << VIRTIO_NET_F_GUEST_ECN) | \ (1ULL << VIRTIO_NET_F_GUEST_UFO)) But there's no guarantee that e.g. VIRTIO_NET_F_GUEST_TSO6 is set. If it isn't command should not send it. Revert the original commit for now. Cc: Tonghao Zhang <xiangxia.m.yue@gmail.com> Cc: Willem de Bruijn <willemb@google.com> Fixes: 3618ad2a7c0e7 ("virtio-net: ethtool configurable RXCSUM") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/net/virtio_net.c | 50 +++++++++++----------------------------- 1 file changed, 13 insertions(+), 37 deletions(-)