Hi Tomasz,
On 03/05/2018 04:59 PM, Tomasz Kulasek wrote:
vhost-net devices might keep track of last descriptors indices by
themselves, and assuming they initially start at 0, but that is not the
case for vhost-scsi. Initial last descriptor indices are set via
VHOST_USER_SET_VRING_BASE message, and we cannot possibly predict what
will they be. Setting these to vqueue->used->idx is also not an option,
because there might be some yet unprocessed requests between these and
the actual last_idx. This patch adds API for getting/setting last
descriptor indices of vrings, so that they can be synchronized between
user-device and rte_vhost.
The last_idx flow could be as following:
* vhost start,
* received SET_VRING_BASE msg, last_idx is set on rte_vhost side,
* created user-device, last_idx pulled from rte_vhost,
* requests are being processed by user-device, last_idx changes,
* destroyed user-device, last_idx pushed to rte_vhost,
* at this point, vrings could be recreated and another SET_VRING_BASE
message could arrive, so last_idx would be set
* recreated user-device, last_idx pulled from rte_vhost.
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojac...@intel.com>
Signed-off-by: Tomasz Kulasek <tomaszx.kula...@intel.com>
---
lib/librte_vhost/rte_vhost.h | 24 ++++++++++++++++++++++++
lib/librte_vhost/vhost.c | 27 +++++++++++++++++++++++++++
2 files changed, 51 insertions(+)
I agree with the patch, but it is missing the declaration of the new API
in rte_vhost_version.map.
Thanks,
Maxime