For auto-translated domain, the only way to map a page to itself is the
using the foreign map API. The current code does not allow mapping page from
special page (such as DOMID_XEN).
As xentrace buffers are shared using DOMID_XEN, it is not possible to use
tracing for Arm.
This could be solved by using the helper get_pg_owner(). This helper will
be able to get a reference on DOMID_XEN and therefore allow mapping for
privileged domain.
This patch replace the call to rcu_lock_domain_by_any_id() with
get_pg_owner(). For consistency, all the call to rcu_unlock_domain are
replaced by put_pg_owner().
Signed-off-by: Julien grall <julien.gr...@arm.com>
Reviewed-by: Andrii Anisov <andrii_ani...@epam.com>
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
---
Changes in v3:
- Add Stefano's reviewed-by
- Fix typoes
Changes in v2:
- Add Andrii's reviewed-by
---
xen/arch/arm/mm.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 3bf11eec4f..01ae2cccc0 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1233,20 +1233,20 @@ int xenmem_add_to_physmap_one(
struct domain *od;
p2m_type_t p2mt;
- od = rcu_lock_domain_by_any_id(extra.foreign_domid);
+ od = get_pg_owner(extra.foreign_domid);
if ( od == NULL )
return -ESRCH;
if ( od == d )
{
- rcu_unlock_domain(od);
+ put_pg_owner(od);
return -EINVAL;
}
rc = xsm_map_gmfn_foreign(XSM_TARGET, d, od);
if ( rc )
{
- rcu_unlock_domain(od);
+ put_pg_owner(od);
return rc;
}
@@ -1255,7 +1255,7 @@ int xenmem_add_to_physmap_one(
page = get_page_from_gfn(od, idx, &p2mt, P2M_ALLOC);
if ( !page )
{
- rcu_unlock_domain(od);
+ put_pg_owner(od);
return -EINVAL;
}
@@ -1264,13 +1264,13 @@ int xenmem_add_to_physmap_one(
else
{
put_page(page);
- rcu_unlock_domain(od);
+ put_pg_owner(od);
return -EINVAL;
}
mfn = page_to_mfn(page);
- rcu_unlock_domain(od);
+ put_pg_owner(od);
break;
}
case XENMAPSPACE_dev_mmio:
--
2.11.0
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
