On Fri, 29 Nov 2019 10:31:36 +0100 Paolo Bonzini <pbonz...@redhat.com> wrote:
> On 28/11/19 17:10, Eduardo Habkost wrote: > > On Thu, Nov 28, 2019 at 06:15:16PM +0400, Marc-André Lureau 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. > > > > Can we make this be a "-m" option? > > > > Or, even better: can we make "-m" options be automatically > > translated to memory-backend-* options somehow? > > [...] > Therefore, I think instead of -mem-shared we should add a "-m > memdev=..." option. This option: > > * would be mutually exclusive with both -mem-path > > * would be handled from allocate_system_memory_nonnuma. > > * could be mutually exclusive "-numa node", or could just be mutually > exclusive with "-numa node,memdev=..." (the logical conclusion of that > however would be an undeprecation of "-numa node,mem=...", so that has > to be taken into account as well). the plan was/still is to have memdev for main ram and deprecate "-numa node,mem=..." for new machine types (can't be done for old ones due to migration breakages and old libvirt which uses it). So new machines will be forced to use "-numa memdev" For old machines '-m memdev' provided memory region will used to keep "-numa node,mem=..." working as it's now (however broken it is). > > Paolo > >