diff --git a/Osstest/TestSupport.pm b/Osstest/TestSupport.pm
index bad0458..1377610 100644
--- a/Osstest/TestSupport.pm
+++ b/Osstest/TestSupport.pm
@@ -922,8 +922,9 @@ sub host_reboot ($) {
     });
 }
 
-sub host_get_free_memory($$) {
-    my ($ho,$toolstack) = @_;
+sub host_get_free_memory($) {
+    my ($ho) = @_;
+    my $toolstack = toolstack($ho)->{Command};
     # The line is as followed:
     # free_memory       :   XXXX
     my $info = target_cmd_output_root($ho, "$toolstack info", 10);
@@ -1266,7 +1267,7 @@ sub guest_await_reboot ($$$) {
 
 sub guest_destroy ($$) {
     my ($ho,$gho) = @_;
-    target_cmd_root($ho, toolstack()->{Command}." destroy $gho->{Name}", 40);
+    target_cmd_root($ho, toolstack($ho)->{Command}." destroy $gho->{Name}", 40);
 }
 
 sub guest_create ($$) {
@@ -1557,7 +1558,7 @@ sub guest_check_up ($) {
 
 sub guest_get_state ($$) {
     my ($ho,$gho) = @_;
-    my $domains= target_cmd_output_root($ho, toolstack()->{Command}." list");
+    my $domains= target_cmd_output_root($ho, toolstack($ho)->{Command}." list");
     $domains =~ s/^Name.*\n//;
     foreach my $l (split /\n/, $domains) {
         $l =~ m/^(\S+) (?: \s+ \d+ ){3} \s+ ([-a-z]+) \s/x or die "$l ?";
@@ -1762,7 +1763,7 @@ sub guest_find_domid ($$) {
     my ($ho,$gho) = @_;
     return if defined $gho->{Domid};
     my $list= target_cmd_output_root($ho,
-                toolstack()->{Command}." list $gho->{Name}");
+                toolstack($ho)->{Command}." list $gho->{Name}");
     $list =~ m/^(?!Name\s)(\S+)\s+(\d+)\s+(\d+)+(\d+)\s.*$/m
         or die "domain list: $list";
     $1 eq $gho->{Name} or die "domain list name $1 expected $gho->{Name}";
@@ -1832,7 +1833,9 @@ our %toolstacks=
         },
      );
 
-sub toolstack () {
+sub toolstack ($) {
+    my ($ho) = @_;
+    return $ho->{Toolstack} if $ho->{Toolstack};
     my $tsname= $r{toolstack};
     $tsname= 'xend' if !defined $tsname;
     my $ts= $toolstacks{$tsname};
@@ -1841,6 +1844,7 @@ sub toolstack () {
         logm("toolstack $tsname");
         $ts->{Name}= $tsname;
     }
+    $ho->{Toolstack} = $ts;
     return $ts;
 }
 
diff --git a/ts-debian-fixup b/ts-debian-fixup
index f001418..11e956c 100755
--- a/ts-debian-fixup
+++ b/ts-debian-fixup
@@ -142,7 +142,7 @@ sub otherfixupcfg () {
     if (@pcipt) {
         logm("checking passthrough device(s) are assignable: @pcipt");
         my @assignables= split /\n/,
-            target_cmd_output_root($ho, toolstack()->{Command}.
+            target_cmd_output_root($ho, toolstack($ho)->{Command}.
                                    " pci-assignable-list");
         foreach my $pcipt (@pcipt) {
             die "not assignable: $pcipt (not in: @assignables)"
diff --git a/ts-debian-hvm-install b/ts-debian-hvm-install
index 37eade2..0148eef 100755
--- a/ts-debian-hvm-install
+++ b/ts-debian-hvm-install
@@ -41,7 +41,7 @@ our $disk_mb= 10000;
 our $guesthost= "$gn.guest.osstest";
 our $gho;
 
-our $toolstack= toolstack()->{Command};
+our $toolstack= toolstack($ho)->{Command};
 
 
 sub preseed () {
@@ -171,7 +171,7 @@ sub prep () {
 
 # If host has >8G free memory, create a guest with 4G memory to catch
 # any error that triggers cross 4G boundary
-my $host_freemem_mb = host_get_free_memory($ho, $toolstack);
+my $host_freemem_mb = host_get_free_memory($ho);
 my $ram_minslop = 100;
 my $ram_lots = 5000;
 if ($host_freemem_mb > $ram_lots * 2 + $ram_minslop) {
diff --git a/ts-guest-localmigrate b/ts-guest-localmigrate
index e50e93a..f3381da 100755
--- a/ts-guest-localmigrate
+++ b/ts-guest-localmigrate
@@ -33,7 +33,7 @@ our ($ho,$gho) = ts_get_host_guest(@ARGV);
 sub migrate () {
     guest_checkrunning($ho,$gho) or die $gho->{Name};
     target_cmd_root($ho,
-		    toolstack()->{Command}
+		    toolstack($ho)->{Command}
 		    ." migrate $gho->{Name} localhost",
 		    $timeout{Migrate});
 }
diff --git a/ts-guest-migrate b/ts-guest-migrate
index 17ac8a0..65e7b42 100755
--- a/ts-guest-migrate
+++ b/ts-guest-migrate
@@ -32,7 +32,7 @@ sub migrate () {
     guest_checkrunning($sho,$gho) or die $gho->{Name};
     my $err= guest_check_ip($gho);  die "$err $gho->{Name}" if defined $err;
     target_cmd_root($sho,
-		    toolstack()->{Command}
+		    toolstack($sho)->{Command}
 		    ." migrate $gho->{Name} $dho->{Name}",
 		    $timeout{Migrate});
 }
diff --git a/ts-guest-saverestore b/ts-guest-saverestore
index 81671c8..9e04ae9 100755
--- a/ts-guest-saverestore
+++ b/ts-guest-saverestore
@@ -28,17 +28,17 @@ sub save () {
     guest_checkrunning($ho,$gho) or die $gho->{Name};
     my $err= guest_check_ip($gho);  die "$err $gho->{Name}" if defined $err;
     target_cmd_root($ho,
-		    toolstack()->{Command}
+		    toolstack($ho)->{Command}
 		    ." save $gho->{Name} image",
 		    200);
     target_ping_check_down($gho);
 }
 sub restore () {
     target_cmd_root($ho,
-		    toolstack()->{Command}
+		    toolstack($ho)->{Command}
 		    ." restore "
-		    .(toolstack()->{RestoreNeedsConfig} ?
-		      $r{ $gho->{Guest}.'_'. toolstack()->{CfgPathVar} } : '')
+		    .(toolstack($ho)->{RestoreNeedsConfig} ?
+		      $r{ $gho->{Guest}.'_'. toolstack($ho)->{CfgPathVar} } : '')
 		    ." image", 200);
     target_ping_check_up($gho);
 }
diff --git a/ts-guest-start b/ts-guest-start
index 057afe6..bfbb734 100755
--- a/ts-guest-start
+++ b/ts-guest-start
@@ -26,8 +26,8 @@ our ($ho,$gho) = ts_get_host_guest(@ARGV);
 
 sub start () {
     guest_umount_lv($ho, $gho);
-    my $cmd= toolstack()->{Command}." create ".
-        $r{ $gho->{Guest}.'_'. toolstack()->{CfgPathVar} };
+    my $cmd= toolstack($ho)->{Command}." create ".
+        $r{ $gho->{Guest}.'_'. toolstack($ho)->{CfgPathVar} };
     target_cmd_root($ho, $cmd, 30);
 }
 
diff --git a/ts-guest-stop b/ts-guest-stop
index cc7db4c..0e3a863 100755
--- a/ts-guest-stop
+++ b/ts-guest-stop
@@ -27,7 +27,7 @@ our ($ho,$gho) = ts_get_host_guest(@ARGV);
 sub stop () {
     guest_checkrunning($ho, $gho) or die "$gho->{Name} not running";
     target_cmd_root($ho,
-		    toolstack()->{Command}
+		    toolstack($ho)->{Command}
 		    ." shutdown -w "
 		    .$gho->{Name}, 200);
     guest_checkrunning($ho, $gho) and die $gho->{Name};
diff --git a/ts-logs-capture b/ts-logs-capture
index ae32883..9df5485 100755
--- a/ts-logs-capture
+++ b/ts-logs-capture
@@ -192,7 +192,7 @@ sub fetch_logs_guest ($) {
         logm("cannot find domid: $@");
         return;
     }
-    my $consolecmd= toolstack()->{Command}." console $gho->{Name}";
+    my $consolecmd= toolstack($ho)->{Command}." console $gho->{Name}";
     try_cmd_output_save("sleep 1 | $consolecmd | cat",
                         "guest-$gho->{Name}-console");
 
diff --git a/ts-migrate-support-check b/ts-migrate-support-check
index ffae1b3..c70b77a 100755
--- a/ts-migrate-support-check
+++ b/ts-migrate-support-check
@@ -25,9 +25,9 @@ tsreadconfig();
 our $ho = selecthost($ARGV[0]);
 
 # all xend/xm platforms support migration
-exit(0) if toolstack()->{Command} eq "xm";
+exit(0) if toolstack($ho)->{Command} eq "xm";
 
-my $help = target_cmd_output_root($ho, toolstack()->{Command}." help");
+my $help = target_cmd_output_root($ho, toolstack($ho)->{Command}." help");
 
 my $rc = ($help =~ m/^\s*migrate/m) ? 0 : 1;
 
diff --git a/ts-redhat-install b/ts-redhat-install
index 56d4129..a0b1fab 100755
--- a/ts-redhat-install
+++ b/ts-redhat-install
@@ -37,7 +37,7 @@ our $disk_mb= 50000;
 our $guesthost= "$gn.guest.osstest";
 our $gho;
 
-our $xl= toolstack()->{Command};
+our $xl= toolstack($ho)->{Command};
 
 
 sub kickstart () {
diff --git a/ts-windows-install b/ts-windows-install
index 0a69f8e..4b06310 100755
--- a/ts-windows-install
+++ b/ts-windows-install
@@ -50,7 +50,7 @@ END
 }
 
 sub start () {
-    target_cmd_root($ho, toolstack()->{Command}.
+    target_cmd_root($ho, toolstack($ho)->{Command}.
                     " create $gho->{CfgPath}", 100);
 }
 
diff --git a/ts-xen-install b/ts-xen-install
index 0b84b7b..31cd7c3 100755
--- a/ts-xen-install
+++ b/ts-xen-install
@@ -60,8 +60,8 @@ sub packages () {
     if ($r{arch} eq 'i386') {
 	target_install_packages($ho, 'libc6-xen');
     }
-    target_install_packages($ho, @{toolstack()->{ExtraPackages}})
-        if toolstack()->{ExtraPackages};
+    target_install_packages($ho, @{toolstack($ho)->{ExtraPackages}})
+        if toolstack($ho)->{ExtraPackages};
 }
 
 sub extract () {
@@ -101,7 +101,7 @@ sub adjustconfig () {
 	    }
 	}
 	print EO $extra or die $!;
-    }) if toolstack()->{Name} eq "xend";
+    }) if toolstack($ho)->{Name} eq "xend";
 
     my $trace_config_file;
     foreach my $try (qw(/etc/default/xencommons
@@ -147,7 +147,7 @@ sub setupboot () {
     } else {
 	mlog("No Xen console device defined for host");
     }
-    if (toolstack()->{Dom0MemFixed}) {
+    if (toolstack($ho)->{Dom0MemFixed}) {
         $xenhopt .= " dom0_mem=512M,max:512M";
     }
     my $append= $r{xen_boot_append};
@@ -179,7 +179,7 @@ sub setupboot () {
 our $initscripts_nobridge;
 
 sub setupinitd () {
-    my $ts= toolstack();
+    my $ts= toolstack($ho);
     my $xencommons= '/etc/init.d/xencommons';
     my $have_xencommons=
         !!target_cmd_output_root($ho, <<END);
