sorry for occasionally reply to old thread.
On Wed, Feb 20, 2019 at 11:02:42AM +0000, Vadim Lomovtsev wrote: > The ThunderX CN88XX NIC Virtual Function driver uses mailbox interface > to communicate to physical function driver. Each of VF has it's own pair > of mailbox registers to read from and write to. The mailbox registers > has no protection from possible races, so it has to be implemented > at software side. > > After long term testing by loop of 'ip link set <ifname> up/down' > command it was found that there are two possible scenarios when > race condition appears: > 1. VF receives link change message from PF and VF send RX mode > configuration message to PF in the same time from separate thread. > 2. PF receives RX mode configuration from VF and in the same time, > in separate thread PF detects link status change and sends appropriate > message to particular VF. > > Both cases leads to mailbox data to be rewritten, NIC VF messaging control > data to be updated incorrectly and communication sequence gets broken. > > This patch series is to address race condition with VF & PF communication. > > Changes: > v1 -> v2 > - 0000: correct typo in cover letter subject: 'betwen' -> 'between'; > - move link state polling request task from pf to vf > instead of cheking status of mailbox irq; > v2 -> v3 > - 0003: change return type of nicvf_send_cfg_done() function > from int to void; > - 0007: update subject and remove unused variable 'netdev' > from nicvf_link_status_check_task() function; > > Vadim Lomovtsev (8): > net: thunderx: correct typo in macro name > net: thunderx: replace global nicvf_rx_mode_wq work queue for all VFs > to private for each of them. > net: thunderx: make CFG_DONE message to run through generic send-ack > sequence > net: thunderx: add nicvf_send_msg_to_pf result check for > set_rx_mode_task > net: thunderx: rework xcast message structure to make it fit into 64 > bit > net: thunderx: add mutex to protect mailbox from concurrent calls for > same VF > net: thunderx: add LINK_CHANGE message handler at nicpf > net: thunderx: remove link change polling code and info from nicpf > > drivers/net/ethernet/cavium/thunder/nic.h | 14 +- > .../net/ethernet/cavium/thunder/nic_main.c | 149 ++++++------------ > .../net/ethernet/cavium/thunder/nicvf_main.c | 130 ++++++++++----- > .../net/ethernet/cavium/thunder/thunder_bgx.c | 2 +- > .../net/ethernet/cavium/thunder/thunder_bgx.h | 2 +- > 5 files changed, 144 insertions(+), 153 deletions(-) > > -- > 2.17.2
