From: Tim Deegan <Tim.Deegan@xensource.com>
Date: Tue, 2 Jan 2007 10:57:50 +0000 (+0000)
Subject: [HVM] Don't set the shadow allocation to zero if the dom is still shadowed.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15422^2~111
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=66e92e7a4885fca3122068e659340daf2b663f6c;p=xen.git

[HVM] Don't set the shadow allocation to zero if the dom is still shadowed.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
---

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 8d9676b159..fc68fd9242 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -3306,6 +3306,15 @@ int shadow_domctl(struct domain *d,
 
     case XEN_DOMCTL_SHADOW_OP_SET_ALLOCATION:
         shadow_lock(d);
+        if ( sc->mb == 0 && shadow_mode_enabled(d) )
+        {            
+            /* Can't set the allocation to zero unless the domain stops using
+             * shadow pagetables first */
+            SHADOW_ERROR("Can't set shadow allocation to zero, domain %u"
+                         " is still using shadows.\n", d->domain_id);
+            shadow_unlock(d);
+            return -EINVAL;
+        }
         rc = sh_set_allocation(d, sc->mb << (20 - PAGE_SHIFT), &preempted);
         shadow_unlock(d);
         if ( preempted )