Re: [RFC PATCH v1 1/7] contrib/vhost-user-blk: add option to simulate disconnect on init

[Dima Stepanov <dimastep@yandex-team.ru>]

On Fri, Apr 24, 2020 at 12:17:54PM +0200, Marc-André Lureau wrote:
> Hi
> 
> On Fri, Apr 24, 2020 at 4:32 AM Raphael Norwitz
> <raphael.norwitz@nutanix.com> wrote:
> >
> > I’m not opposed to adding this kind of debugging functionality to the
> > vhost-user-blk sample. It could be helpful to easily test these cases
> > in the future.
> >
> > That said, I'm not sure how others will feel about adding these kind
> > of debugging capabilities to libvhost-user. Marc-Andre, thoughts?
> 
> Maybe we should only enable this code if LIBVHOST_USER_DEBUG is set?
> 
> And to make logging silent by default, we shouldn't print them unless
> VHOST_USER_DEBUG env is set?
Yes, it is a good idea to move this code under LIBVHOST_USER_DEBUG.
Agree. Will update it in version 2, but need more feedback on other
patches first.

> 
> >
> > If we go this route I would prefer to add the debugging options to the
> > vhost-user-blk sample in a separate patch.
> >
> > On Thu, Apr 23, 2020 at 09:39:32PM +0300, Dima Stepanov wrote:
> > >
> > > Add "--simulate-disconnect-stage" option for the testing purposes.
> > > This option can be used to test the vhost-user reconnect functionality:
> > >   ./vhost-user-blk ... --simulate-disconnect-stage=<CASENUM>
> > > In this case the daemon will "crash" in the middle of the VHOST comands
> > > communication. Case nums are as follows:
> > >   1 - make assert in the handler of the SET_VRING_CALL command
> > >   2 - make assert in the handler of the SET_VRING_NUM command
> > > Main purpose is to test QEMU reconnect functionality. Such fail
> > > injection should not lead to QEMU crash and should be handled
> > > successfully.
> > > Also update the "GOptionEntry entries" definition with the final NULL
> > > item according to API.
> > >
> > > Signed-off-by: Dima Stepanov <dimastep@yandex-team.ru>
> > > ---
> > >  contrib/libvhost-user/libvhost-user.c   | 30 ++++++++++++++++++++++++++++++
> > >  contrib/libvhost-user/libvhost-user.h   | 13 +++++++++++++
> > >  contrib/vhost-user-blk/vhost-user-blk.c | 14 +++++++++++++-
> > >  3 files changed, 56 insertions(+), 1 deletion(-)
> >
>