[PATCH 3/7] xen: prevent 0 from being used as a dynamic domid

From: Daniel De Graaf <dgdegra@tycho.nsa.gov>
To: xen-devel@lists.xen.org
Cc: dgdegra@tycho.nsa.gov, Keir Fraser <keir@xen.org>
Subject: [PATCH 3/7] xen: prevent 0 from being used as a dynamic domid
Date: Thu, 27 Mar 2014 07:52:04 -0400	[thread overview]
Message-ID: <1395921128-7086-4-git-send-email-dgdegra@tycho.nsa.gov> (raw)
In-Reply-To: <1395921128-7086-1-git-send-email-dgdegra@tycho.nsa.gov>

When the hardware domain is made distinct from dom0, it becomes possible
to shut down and destroy domain 0 while leaving the hypervisor running.
If this happens, prevent this domain ID from being considered for
allocation to a new guest.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Cc: Keir Fraser <keir@xen.org>
---
 xen/common/domctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 7cf610a..eebeee7 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -436,7 +436,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
             for ( dom = rover + 1; dom != rover; dom++ )
             {
                 if ( dom == DOMID_FIRST_RESERVED )
-                    dom = 0;
+                    dom = 1;
                 if ( is_free_domid(dom) )
                     break;
             }
-- 
1.8.5.3
