From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gavin Shan Date: Mon, 9 Jan 2017 10:45:10 +1100 Subject: [Intel-wired-lan] [PATCH v2] PCI: lock each enable/disable num_vfs operation in sysfs In-Reply-To: <20170106215908.20736.34632.stgit@localhost6.localdomain6> References: <20170106215908.20736.34632.stgit@localhost6.localdomain6> Message-ID: <20170108234510.GA14008@gwshan> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Fri, Jan 06, 2017 at 01:59:08PM -0800, Emil Tantilov wrote: >Enabling/disabling SRIOV via sysfs by echo-ing multiple values >simultaneously: > >echo 63 > /sys/class/net/ethX/device/sriov_numvfs& >echo 63 > /sys/class/net/ethX/device/sriov_numvfs > >sleep 5 > >echo 0 > /sys/class/net/ethX/device/sriov_numvfs& >echo 0 > /sys/class/net/ethX/device/sriov_numvfs > >Results in the following bug: > >kernel BUG at drivers/pci/iov.c:495! >invalid opcode: 0000 [#1] SMP >CPU: 1 PID: 8050 Comm: bash Tainted: G W 4.9.0-rc7-net-next #2092 >RIP: 0010:[] > [] pci_iov_release+0x57/0x60 > >Call Trace: > [] pci_release_dev+0x26/0x70 > [] device_release+0x3e/0xb0 > [] kobject_cleanup+0x67/0x180 > [] kobject_put+0x2d/0x60 > [] put_device+0x17/0x20 > [] pci_dev_put+0x1a/0x20 > [] pci_get_dev_by_id+0x5b/0x90 > [] pci_get_subsys+0x35/0x40 > [] pci_get_device+0x18/0x20 > [] pci_get_domain_bus_and_slot+0x2b/0x60 > [] pci_iov_remove_virtfn+0x57/0x180 > [] pci_disable_sriov+0x65/0x140 > [] ixgbe_disable_sriov+0xc7/0x1d0 [ixgbe] > [] ixgbe_pci_sriov_configure+0x3d/0x170 [ixgbe] > [] sriov_numvfs_store+0xdc/0x130 >... >RIP [] pci_iov_release+0x57/0x60 > >Use the existing mutex lock to protect each enable/disable operation. > >-v2: move the existing lock from protecting the config of the IOV bus >to protecting the writes to sriov_numvfs in sysfs without maintaining >a "locked" version of pci_iov_add/remove_virtfn(). >As suggested by Gavin Shan > >CC: Alexander Duyck >Signed-off-by: Emil Tantilov >--- Reviewed-by: Gavin Shan