On 7/8/22 12:25, Saini, Abhimanyu wrote:
[AMD Official Use Only - General]
Sorry Maxime, I forgot to copy stable.
Yes it's required, the faulty commit is :
630be406dcbfc26260e9d9688c40a381d0f012db
Thanks, ammended the commit message and applied to
dpdk-next-virtio/main.
-----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
