From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maciej Fijalkowski Date: Thu, 19 May 2022 11:58:32 +0200 Subject: [Intel-wired-lan] [PATCH v2] ixgbe: Add locking to prevent panic when setting sriov_numvfs to zero In-Reply-To: <20220519055358.20314-1-piotrx.skajewski@intel.com> References: <20220519055358.20314-1-piotrx.skajewski@intel.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Thu, May 19, 2022 at 07:53:58AM +0200, Piotr Skajewski wrote: > It is possible to disable VFs while the PF driver is processing requests > from the VF driver. This can result in a panic. > > BUG: unable to handle kernel paging request at 000000000000106c > PGD 0 P4D 0 > Oops: 0000 [#1] SMP NOPTI > CPU: 8 PID: 0 Comm: swapper/8 Kdump: loaded Tainted: G I --------- - > Hardware name: Dell Inc. PowerEdge R740/06WXJT, BIOS 2.8.2 08/27/2020 > RIP: 0010:ixgbe_msg_task+0x4c8/0x1690 [ixgbe] > Code: 00 00 48 8d 04 40 48 c1 e0 05 89 7c 24 24 89 fd 48 89 44 24 10 83 ff > 01 0f 84 b8 04 00 00 4c 8b 64 24 10 4d 03 a5 48 22 00 00 <41> 80 7c 24 4c > 00 0f 84 8a 03 00 00 0f b7 c7 83 f8 08 0f 84 8f 0a > RSP: 0018:ffffb337869f8df8 EFLAGS: 00010002 > RAX: 0000000000001020 RBX: 0000000000000000 RCX: 000000000000002b > RDX: 0000000000000002 RSI: 0000000000000008 RDI: 0000000000000006 > RBP: 0000000000000006 R08: 0000000000000002 R09: 0000000000029780 > R10: 00006957d8f42832 R11: 0000000000000000 R12: 0000000000001020 > R13: ffff8a00e8978ac0 R14: 000000000000002b R15: ffff8a00e8979c80 > FS: 0000000000000000(0000) GS:ffff8a07dfd00000(0000) knlGS:00000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000000106c CR3: 0000000063e10004 CR4: 00000000007726e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > PKRU: 55555554 > Call Trace: > > ? ttwu_do_wakeup+0x19/0x140 > ? try_to_wake_up+0x1cd/0x550 > ? ixgbevf_update_xcast_mode+0x71/0xc0 [ixgbevf] > ixgbe_msix_other+0x17e/0x310 [ixgbe] > __handle_irq_event_percpu+0x40/0x180 > handle_irq_event_percpu+0x30/0x80 > handle_irq_event+0x36/0x53 > handle_edge_irq+0x82/0x190 > handle_irq+0x1c/0x30 > do_IRQ+0x49/0xd0 > common_interrupt+0xf/0xf > > This can be eventually be reproduced with the following script: > > while : > do > echo 63 > /sys/class/net//device/sriov_numvfs > sleep 1 > echo 0 > /sys/class/net//device/sriov_numvfs > sleep 1 > done > > Add lock when disabling SR-IOV to prevent process VF mailbox communication. > > Signed-off-by: Piotr Skajewski This is a fix for sure. Please target it to net tree and add fixes tag. > --- > changes in v2: > - replace type spin_lock_bh to spin_lock Why? Please explain what contexts are being synchronized.k > > drivers/net/ethernet/intel/ixgbe/ixgbe.h | 1 + > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 3 ++ > .../net/ethernet/intel/ixgbe/ixgbe_sriov.c | 28 ++++++++++++------- > 3 files changed, 22 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > index 921a4d977d65..8813b4dd6872 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > @@ -779,6 +779,7 @@ struct ixgbe_adapter { > #ifdef CONFIG_IXGBE_IPSEC > struct ixgbe_ipsec *ipsec; > #endif /* CONFIG_IXGBE_IPSEC */ > + spinlock_t vfs_lock; > }; > > static inline int ixgbe_determine_xdp_q_idx(int cpu) > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > index c4a4954aa317..6c403f112d29 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > @@ -6402,6 +6402,9 @@ static int ixgbe_sw_init(struct ixgbe_adapter *adapter, > /* n-tuple support exists, always init our spinlock */ > spin_lock_init(&adapter->fdir_perfect_lock); > > + /* init spinlock to avoid concurrency of VF resources */ > + spin_lock_init(&adapter->vfs_lock); > + > #ifdef CONFIG_IXGBE_DCB > ixgbe_init_dcb(adapter); > #endif > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c > index 7f11c0a8e7a9..6f583df19635 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c > @@ -207,6 +207,8 @@ int ixgbe_disable_sriov(struct ixgbe_adapter *adapter) > unsigned int num_vfs = adapter->num_vfs, vf; > int rss; > > + spin_lock(&adapter->vfs_lock); > + > /* set num VFs to 0 to prevent access to vfinfo */ > adapter->num_vfs = 0; > > @@ -228,6 +230,8 @@ int ixgbe_disable_sriov(struct ixgbe_adapter *adapter) > kfree(adapter->mv_list); > adapter->mv_list = NULL; > > + spin_unlock(&adapter->vfs_lock); > + > /* if SR-IOV is already disabled then there is nothing to do */ > if (!(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)) > return 0; > @@ -1357,19 +1361,23 @@ void ixgbe_msg_task(struct ixgbe_adapter *adapter) > struct ixgbe_hw *hw = &adapter->hw; > u32 vf; > > - for (vf = 0; vf < adapter->num_vfs; vf++) { > - /* process any reset requests */ > - if (!ixgbe_check_for_rst(hw, vf)) > - ixgbe_vf_reset_event(adapter, vf); > + spin_lock(&adapter->vfs_lock); > + if (adapter->vfinfo) { why this is needed? also maybe revert the logic and flatten the code: if (!adapter->vfinfo) goto unlock; (...) unlock: spin_unlock(&adapter->vfs_lock); > + for (vf = 0; vf < adapter->num_vfs; vf++) { > + /* process any reset requests */ > + if (!ixgbe_check_for_rst(hw, vf)) > + ixgbe_vf_reset_event(adapter, vf); > > - /* process any messages pending */ > - if (!ixgbe_check_for_msg(hw, vf)) > - ixgbe_rcv_msg_from_vf(adapter, vf); > + /* process any messages pending */ > + if (!ixgbe_check_for_msg(hw, vf)) > + ixgbe_rcv_msg_from_vf(adapter, vf); > > - /* process any acks */ > - if (!ixgbe_check_for_ack(hw, vf)) > - ixgbe_rcv_ack_from_vf(adapter, vf); > + /* process any acks */ > + if (!ixgbe_check_for_ack(hw, vf)) > + ixgbe_rcv_ack_from_vf(adapter, vf); > + } > } > + spin_unlock(&adapter->vfs_lock); > } > > static inline void ixgbe_ping_vf(struct ixgbe_adapter *adapter, int vf) > -- > 2.35.0.rc0 > > _______________________________________________ > Intel-wired-lan mailing list > Intel-wired-lan at osuosl.org > https://lists.osuosl.org/mailman/listinfo/intel-wired-lan