From 4cf0a6185895d4ebd939c09ba242eaab89d0a0e2 Mon Sep 17 00:00:00 2001
From: Rafal Wojtczuk <rafal@invisiblethingslab.com>
Date: Thu, 22 Jul 2010 14:54:34 +0200
Subject: [PATCH] Before restoring DVM, check for available xen memory

As we already do xm mem-set 0 800 in qubes_core, this is a
correct check. Now, there should be no errors from qubes_restore
in normal circumstances.
---
 dom0/pendrive_swapper/qfilexchgd | 10 ++++++++++
 dom0/restore/Makefile            |  9 +++++++--
 dom0/restore/xenfreepages.c      | 18 ++++++++++++++++++
 rpm_spec/core-dom0.spec          |  3 ++-
 4 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 dom0/restore/xenfreepages.c

diff --git a/dom0/pendrive_swapper/qfilexchgd b/dom0/pendrive_swapper/qfilexchgd
index be7f4650..03d3cc8f 100755
--- a/dom0/pendrive_swapper/qfilexchgd
+++ b/dom0/pendrive_swapper/qfilexchgd
@@ -187,6 +187,16 @@ class DomainState:
 
     def handle_transfer_disposable(self, transaction_seq):
 
+        mem_for_dvm = 400
+        xenfreepages_s = subprocess.Popen(["/usr/lib/qubes/xenfreepages"],stdout=subprocess.PIPE).stdout.readline()
+        xenfree_mb = int(xenfreepages_s)*4096/1024/1024
+        if xenfree_mb < mem_for_dvm:
+            errmsg = 'Not enough memory to create DVM: '
+            errmsg +='have ' + str(xenfree_mb) + 'MB, need '
+            errmsg +=str(mem_for_dvm) + 'MB. Terminate some appVM and retry.'
+            subprocess.call(['/usr/bin/kdialog', '--sorry', errmsg])
+            return False
+
         qvm_collection = QubesVmCollection()
         qvm_collection.lock_db_for_writing()
         qvm_collection.load()
diff --git a/dom0/restore/Makefile b/dom0/restore/Makefile
index e279bbb6..e5f1addb 100644
--- a/dom0/restore/Makefile
+++ b/dom0/restore/Makefile
@@ -1,9 +1,14 @@
 CC=gcc
-all: qubes_restore xenstore-watch
+all: qubes_restore xenstore-watch xenfreepages
 qubes_restore: qubes_restore.o
 	$(CC) -o qubes_restore qubes_restore.o -lxenstore
 
 xenstore-watch: xenstore-watch.o
 	$(CC) -o xenstore-watch xenstore-watch.o -lxenstore
+
+xenfreepages: xenfreepages.o
+	$(CC) -o xenfreepages xenfreepages.o -lxenctrl
+	
 clean:
-	rm -f *.o *~ qubes_restore xenstore-watch
+	rm -f *.o *~ qubes_restore xenstore-watch xenfreepages
+
diff --git a/dom0/restore/xenfreepages.c b/dom0/restore/xenfreepages.c
new file mode 100644
index 00000000..ced36dbb
--- /dev/null
+++ b/dom0/restore/xenfreepages.c
@@ -0,0 +1,18 @@
+#include <xenctrl.h>
+#include <stdio.h>
+#include <stdlib.h>
+struct xen_sysctl_physinfo xphysinfo;
+main()
+{
+	int handle = xc_interface_open();
+	if (handle == -1) {
+		perror("xc_interface_open");
+		exit(1);
+	}
+	if (xc_physinfo(handle, &xphysinfo)) {
+		perror("xc_physinfo");
+		exit(1);
+	}
+	printf("%lld", xphysinfo.free_pages);
+	return 0;
+}
diff --git a/rpm_spec/core-dom0.spec b/rpm_spec/core-dom0.spec
index ef2d1ed5..456d959c 100644
--- a/rpm_spec/core-dom0.spec
+++ b/rpm_spec/core-dom0.spec
@@ -79,7 +79,7 @@ cp aux-tools/remove_appvm_appmenus.sh $RPM_BUILD_ROOT/usr/lib/qubes
 cp pendrive_swapper/qubes_pencmd $RPM_BUILD_ROOT/usr/lib/qubes
 
 cp restore/xenstore-watch restore/qvm-create-default-dvm $RPM_BUILD_ROOT/usr/bin
-cp restore/qubes_restore  $RPM_BUILD_ROOT/usr/lib/qubes
+cp restore/qubes_restore restore/xenfreepages $RPM_BUILD_ROOT/usr/lib/qubes
 cp restore/qubes_prepare_saved_domain.sh  $RPM_BUILD_ROOT/usr/lib/qubes
 
 mkdir -p $RPM_BUILD_ROOT/var/lib/qubes
@@ -221,3 +221,4 @@ fi
 /usr/lib/qubes/qubes_restore
 /usr/lib/qubes/qubes_prepare_saved_domain.sh
 /etc/xen/scripts/block.qubes
+%attr(4750,root,qubes) /usr/lib/qubes/xenfreepages