[AMD Official Use Only - General] Sorry Maxime, I forgot to copy stable. Yes it's required, the faulty commit is : 630be406dcbfc26260e9d9688c40a381d0f012db
-----Original Message----- From: Maxime Coquelin <maxime.coque...@redhat.com> Sent: Friday, July 8, 2022 2:55 PM To: abhimanyu.sa...@xilinx.com; dev@dpdk.org Cc: chenbo....@intel.com; andrew.rybche...@oktetlabs.ru; Saini, Abhimanyu <abhimanyu.sa...@amd.com> Subject: Re: [PATCH] vdpa/sfc: resolve race between libvhost and dev_conf [CAUTION: External Email] On 7/8/22 11:23, Maxime Coquelin wrote: > > > On 7/6/22 11:24, abhimanyu.sa...@xilinx.com wrote: >> From: Abhimanyu Saini <absa...@amd.com> >> >> libvhost calls dev_conf() before prosessing the >> VHOST_USER_SET_VRING_CALL message for the last VQ. So >> this message is processed after dev_conf() returns. >> >> However, the dev_conf() function spawns a thread to set >> rte_vhost_host_notifier_ctrl() before returning control to >> libvhost. This parallel thread in turn invokes get_notify_area(). >> To get the notify_area, the vdpa driver needs to query the HW and >> for this query it needs an enabled VQ. >> >> But at the same time libvhost is processing the last >> VHOST_USER_SET_VRING_CALL, and to do that it disables the last VQ. >> >> Hence there is a race b/w the libvhost and the vdpa driver. >> >> To resolve this race condition, query the HW and cache notify_area >> inside dev_conf() instead of doing it the parallel thread. >> >> Signed-off-by: Abhimanyu Saini <absa...@amd.com> >> --- >> drivers/vdpa/sfc/sfc_vdpa_ops.c | 36 >> ++++++++++++++++++------------------ >> drivers/vdpa/sfc/sfc_vdpa_ops.h | 1 + >> 2 files changed, 19 insertions(+), 18 deletions(-) >> > > Applied to dpdk-next-virtio/main. Sorry, I notice it is missing the Fixes tag, and cc'ing stable. Can you confirm this is needed and provide the faulty commit? Thanks, Maxime > Thanks, > Maxime
