Re: Inter-domain shared memory facility in Xen?

[Akio Takebe <takebe_akio@jp.fujitsu.com>]

Hi,

>Hopefully this question belongs in xen-devel and not xen-users:
>
>Is there any kind of inter-domain shared memory facility in Xen?  E.g.
>an API callable from DomU user-mode that would cause the system sets
>up two DomU's page tables so they a range of virtual addresses in both
>resolve to the same set of machine pages?
You may be able to use grant table.
Grant table can make shared memroy.

If you want to share memory between dom0 and domU,
you can use the following fanction.

1. HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref) and
   gnttab_grant_foreign_access()
       It is kernel API used in blk split driver.

2. xc_map_foreign_range()
       It is dom0 user API used in xc_core.c.
       It can share memory between dom0 user vaddr and domU guest maddr.

If you want to share memory between domU user vaddr and the other domU's,
you need to make the API.

Best Regards,

Akio Takebe