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(-)
During today's Release status meeting, Andrew mentioned that this patch has been for a log time already in your internal tree. So it gives a bit of confidence in taking it in -rc4. Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com> Thanks, Maxime
