From: Paul Durrant <paul.durrant@citrix.com>
Date: Sun, 18 Dec 2011 14:51:04 +0000 (+0000)
Subject: Allow VMs to query their own grant table version.
X-Git-Tag: 4.0.4-rc1~29
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=c76a11f540161c49347c381bb28f1d28a2062d97;p=xen.git

Allow VMs to query their own grant table version.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
xen-unstable changeset:   24427:931bf1105730
xen-unstable date:        Sun Dec 18 14:38:32 2011 +0000
---

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index e089365964..640969b7d1 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2181,6 +2181,7 @@ static int grant_table_op_is_allowed(unsigned int cmd)
     case GNTTABOP_query_size:
     case GNTTABOP_setup_table:
     case GNTTABOP_set_version:
+    case GNTTABOP_get_version:
     case GNTTABOP_copy:
     case GNTTABOP_map_grant_ref:
     case GNTTABOP_unmap_grant_ref:
diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 8de1af9085..87aff17ac7 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -2199,17 +2199,15 @@ gnttab_get_version(XEN_GUEST_HANDLE(gnttab_get_version_t uop))
 {
     gnttab_get_version_t op;
     struct domain *d;
+    int rc;
 
     if ( copy_from_guest(&op, uop, 1) )
         return -EFAULT;
-    d = rcu_lock_domain_by_id(op.dom);
-    if ( d == NULL )
-        return -ESRCH;
-    if ( !IS_PRIV_FOR(current->domain, d) )
-    {
-        rcu_unlock_domain(d);
-        return -EPERM;
-    }
+
+    rc = rcu_lock_target_domain_by_id(op.dom, &d);
+    if ( rc < 0 )
+        return rc;
+
     spin_lock(&d->grant_table->lock);
     op.version = d->grant_table->gt_version;
     spin_unlock(&d->grant_table->lock);