Re: [PATCH] vhost: add API for getting last_idx of vrings

[Thomas Monjalon <thomas@monjalon.net>]

What is the status of this patch?

19/04/2018 16:57, Maxime Coquelin:
> Hi Tomasz,
> 
> On 03/28/2018 11:31 AM, Kulasek, TomaszX wrote:
> > Hi Maxime,
> > 
> >> -----Original Message-----
> >> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
> >> Sent: Wednesday, March 28, 2018 10:57
> >> To: Kulasek, TomaszX <tomaszx.kulasek@intel.com>; yliu@fridaylinux.org
> >> Cc: Verkamp, Daniel <daniel.verkamp@intel.com>; Harris, James R
> >> <james.r.harris@intel.com>; Wodkowski, PawelX <pawelx.wodkowski@intel.com>;
> >> dev@dpdk.org; Stojaczyk, DariuszX <dariuszx.stojaczyk@intel.com>
> >> Subject: Re: [dpdk-dev] [PATCH] vhost: add API for getting last_idx of vrings
> >>
> >> 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.stojaczyk@intel.com>
> >>> Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@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
> > 
> > Yes, I will send v2.
> 
> Do you plan to send v2 for v18.02?
> It can still make it to -rc2 if you post it early next week.
> 
> Thanks,
> Maxime
> 
> > Tomasz
> > 
>