Re: [PATCH 0/2] RFC: add -mem-shared option

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 28 Nov 2019 16:59:33 +0000
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:

> * Marc-André Lureau (marcandre.lureau@redhat.com) wrote:
> > Hi,
> > 
> > Setting up shared memory for vhost-user is a bit complicated from
> > command line, as it requires NUMA setup such as: m 4G -object
> > memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on -numa
> > node,memdev=mem.
> > 
> > Instead, I suggest to add a -mem-shared option for non-numa setups,
> > that will make the -mem-path or anonymouse memory shareable.
> > 
> > Comments welcome,  
> 
> It's worth checking with Igor (cc'd) - he said he was going to work on
> something similar.
> 
> One other thing this fixes is that it lets you potentially do vhost-user
> on s390, since it currently has no NUMA.
Switching to memdev will let vhost-user on s390 work as well.
This is convenience option and workarounds inability to set main RAM
properties in current impl. 


> Dave
> 
> > Marc-André Lureau (2):
> >   memfd: add qemu_memfd_open()
> >   Add -mem-shared option
> > 
> >  exec.c                  | 11 ++++++++++-
> >  hw/core/numa.c          | 16 +++++++++++++++-
> >  include/qemu/memfd.h    |  3 +++
> >  include/sysemu/sysemu.h |  1 +
> >  qemu-options.hx         | 10 ++++++++++
> >  util/memfd.c            | 39 +++++++++++++++++++++++++--------------
> >  vl.c                    |  4 ++++
> >  7 files changed, 68 insertions(+), 16 deletions(-)
> > 
> > -- 
> > 2.24.0
> > 
> >   
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> 
>