diff --git a/Makefile b/Makefile
index 4717ce05..0ae46dd1 100644
--- a/Makefile
+++ b/Makefile
@@ -12,15 +12,20 @@ help:
 	@echo "make update-repo-installer -- copy dom0 rpms to installer repo"
 	@echo "make clean                 -- cleanup"
 
-rpms:	
+rpms: rpms-vm rpms-dom0
+
+rpms-vm:
 	rpmbuild --define "_rpmdir $(RPMS_DIR)" -bb rpm_spec/core-vm.spec
 	rpmbuild --define "_rpmdir $(RPMS_DIR)" -bb rpm_spec/core-vm-kernel-placeholder.spec
-	rpmbuild --define "_rpmdir $(RPMS_DIR)" -bb rpm_spec/core-dom0.spec
 	rpm --addsign \
-		$(RPMS_DIR)/x86_64/qubes-core-dom0-$(VERSION_DOM0)*.rpm \
 		$(RPMS_DIR)/x86_64/qubes-core-vm-*$(VERSION_VM)*.rpm \
 		$(RPMS_DIR)/x86_64/qubes-core-vm-kernel-placeholder-*.rpm
 
+rpms-dom0:
+	rpmbuild --define "_rpmdir $(RPMS_DIR)" -bb rpm_spec/core-dom0.spec
+	rpm --addsign \
+		$(RPMS_DIR)/x86_64/qubes-core-dom0-$(VERSION_DOM0)*.rpm
+
 rpms-vaio-fixes:
 	rpmbuild --define "_rpmdir $(RPMS_DIR)" -bb rpm_spec/core-dom0-vaio-fixes.spec
 	rpm --addsign $(RPMS_DIR)/x86_64/qubes-core-dom0-vaio-fixes-$(VERSION_VAIO_FIXES)*.rpm 
diff --git a/build-deps.list b/build-deps.list
new file mode 100644
index 00000000..55e78363
--- /dev/null
+++ b/build-deps.list
@@ -0,0 +1 @@
+xen-devel-*DIST*
diff --git a/dom0/qvm-core/qubes.py b/dom0/qvm-core/qubes.py
index 695c806d..82d6fbf7 100755
--- a/dom0/qvm-core/qubes.py
+++ b/dom0/qvm-core/qubes.py
@@ -75,7 +75,7 @@ default_kernels_subdir = "kernels"
 default_firewall_conf_file = "firewall.xml"
 default_memory = 400
 default_kernelopts = ""
-default_kernelopts_pcidevs = "iommu=soft swiotlb=2048"
+default_kernelopts_pcidevs = "iommu=soft swiotlb=4096"
 
 default_hvm_disk_size = 20*1024*1024*1024
 default_hvm_private_img_size = 2*1024*1024*1024
diff --git a/dom0/qvm-tools/qvm-usb b/dom0/qvm-tools/qvm-usb
index 7b062a67..14a1cf24 100755
--- a/dom0/qvm-tools/qvm-usb
+++ b/dom0/qvm-tools/qvm-usb
@@ -26,6 +26,8 @@ from optparse import OptionParser
 import sys
 import os
 
+pvusb_enable_flagfile = '/var/lib/qubes/pvusb-enable.flag'
+
 def main():
     usage = "usage: %prog -l [options]\n"\
             "usage: %prog -a [options] <vm-name> <device-vm-name>:<device>\n"\
@@ -46,6 +48,23 @@ def main():
 
     (options, args) = parser.parse_args ()
 
+    if not os.path.exists(pvusb_enable_flagfile):
+        print >> sys.stderr, ""
+        print >> sys.stderr, "******* WARNING *** WARNING *** WARNING *** WARNING *******"
+        print >> sys.stderr, "***                                                     ***"
+        print >> sys.stderr, "*** PVUSB passthrough kernel support is still unstable. ***"
+        print >> sys.stderr, "***                It can CRASH your VMs                ***"
+        print >> sys.stderr, "***                                                     ***"
+        print >> sys.stderr, "***********************************************************"
+        print >> sys.stderr, ""
+        print >> sys.stderr, "If you still want to use it, type capital YES"
+        print >> sys.stderr, ""
+        prompt = raw_input ("Do you want enable PV USB support? ")
+        if prompt == "YES":
+            open(pvusb_enable_flagfile, "w").close()
+        else:
+            exit(1)
+
     if os.geteuid() == 0:
         if not options.force_root:
             print >> sys.stderr, "*** Running this tool as root is strongly discouraged, this will lead you in permissions problems."
diff --git a/rpm_spec/core-dom0.spec b/rpm_spec/core-dom0.spec
index 7465e944..6845cf31 100644
--- a/rpm_spec/core-dom0.spec
+++ b/rpm_spec/core-dom0.spec
@@ -56,9 +56,10 @@ python -O -m compileall qvm-core qmemman
 make -C restore
 make -C qubes_rpc
 make -C ../qubes_rpc
-make -C ../vchan -f Makefile.linux
 make -C ../u2mfn
+make -C ../vchan -f Makefile.linux
 make -C ../qrexec
+make -C ../misc
 
 %install
 
diff --git a/rpm_spec/core-vm.spec b/rpm_spec/core-vm.spec
index 763e6b19..64884eac 100644
--- a/rpm_spec/core-vm.spec
+++ b/rpm_spec/core-vm.spec
@@ -212,7 +212,7 @@ remove_ShowIn () {
 for F in abrt-applet deja-dup-monitor imsettings-start krb5-auth-dialog pulseaudio restorecond sealertauto gnome-power-manager gnome-sound-applet gnome-screensaver orca-autostart; do
 	if [ -e /etc/xdg/autostart/$F.desktop ]; then
 		remove_ShowIn $F
-		echo 'NotShowIn=QUBES' >> /etc/xdg/autostart/$F.desktop
+		echo 'NotShowIn=QUBES;' >> /etc/xdg/autostart/$F.desktop
 	fi
 done
 
@@ -220,7 +220,7 @@ done
 for F in gcm-apply ; do
 	if [ -e /etc/xdg/autostart/$F.desktop ]; then
 		remove_ShowIn $F
-		echo 'NotShowIn=DisposableVM' >> /etc/xdg/autostart/$F.desktop
+		echo 'NotShowIn=DisposableVM;' >> /etc/xdg/autostart/$F.desktop
 	fi
 done
 
diff --git a/u2mfn/u2mfnlib.c b/u2mfn/u2mfnlib.c
index 998f47e9..dff06e43 100644
--- a/u2mfn/u2mfnlib.c
+++ b/u2mfn/u2mfnlib.c
@@ -31,11 +31,24 @@ static int u2mfn_fd = -1;
 
 static int get_fd()
 {
-	if (u2mfn_fd == -1) {
-		u2mfn_fd = open("/proc/u2mfn", O_RDWR);
-		if (u2mfn_fd < 0)
-			return -1;
-	}
+	if (u2mfn_fd == -1)
+		u2mfn_fd = u2mfn_get_fd();
+	if (u2mfn_fd < 0)
+		return -1;
+	return 0;
+}
+
+int u2mfn_get_fd()
+{
+	return open("/proc/u2mfn", O_RDWR);
+}
+
+int u2mfn_get_mfn_for_page_with_fd(int fd, long va, int *mfn)
+{
+	*mfn = ioctl(fd, U2MFN_GET_MFN_FOR_PAGE, va);
+	if (*mfn == -1)
+		return -1;
+
 	return 0;
 }
 
@@ -43,7 +56,12 @@ int u2mfn_get_mfn_for_page(long va, int *mfn)
 {
 	if (get_fd())
 		return -1;
-	*mfn = ioctl(u2mfn_fd, U2MFN_GET_MFN_FOR_PAGE, va);
+	return u2mfn_get_mfn_for_page_with_fd(u2mfn_fd, va, mfn);
+}
+
+int u2mfn_get_last_mfn_with_fd(int fd, int *mfn)
+{
+	*mfn = ioctl(fd, U2MFN_GET_LAST_MFN, 0);
 	if (*mfn == -1)
 		return -1;
 
@@ -54,22 +72,20 @@ int u2mfn_get_last_mfn(int *mfn)
 {
 	if (get_fd())
 		return -1;
-
-	*mfn = ioctl(u2mfn_fd, U2MFN_GET_LAST_MFN, 0);
-	if (*mfn == -1)
-		return -1;
-
-	return 0;
+	return u2mfn_get_last_mfn_with_fd(u2mfn_fd, mfn);
 }
 
-
+char *u2mfn_alloc_kpage_with_fd(int fd)
+{
+	char *ret;
+	ret =
+	    mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	return ret;
+}
 
 char *u2mfn_alloc_kpage()
 {
-	char *ret;
 	if (get_fd())
 		return MAP_FAILED;
-	ret =
-	    mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, u2mfn_fd, 0);
-	return ret;
+	return u2mfn_alloc_kpage_with_fd(u2mfn_fd);
 }
diff --git a/u2mfn/u2mfnlib.h b/u2mfn/u2mfnlib.h
index e64431af..a7c20972 100644
--- a/u2mfn/u2mfnlib.h
+++ b/u2mfn/u2mfnlib.h
@@ -19,6 +19,10 @@
  *
  */
 
+int u2mfn_get_fd();
 int u2mfn_get_mfn_for_page(long va, int *mfn) ;
+int u2mfn_get_mfn_for_page_with_fd(int fd, long va, int *mfn) ;
 int u2mfn_get_last_mfn(int *mfn) ;
-char *u2mfn_alloc_kpage(void) ;
+int u2mfn_get_last_mfn_with_fd(int fd, int *mfn) ;
+char *u2mfn_alloc_kpage(void);
+char *u2mfn_alloc_kpage_with_fd(int fd);
diff --git a/vchan/init.c b/vchan/init.c
index 09e05ff9..1bba4e68 100644
--- a/vchan/init.c
+++ b/vchan/init.c
@@ -92,6 +92,7 @@ static int ring_init(struct libvchan *ctrl)
 static int ring_init(struct libvchan *ctrl)
 {
 	int mfn;
+	int u2mfn_fd;
 	struct vchan_interface *ring;
 #ifdef CONFIG_STUBDOM
 	ring = (struct vchan_interface *) memalign(XC_PAGE_SIZE, sizeof(*ring));
@@ -102,12 +103,15 @@ static int ring_init(struct libvchan *ctrl)
 
 	mfn = virtual_to_mfn(ring);
 #else
-	ring = (struct vchan_interface *) u2mfn_alloc_kpage ();
+	u2mfn_fd = u2mfn_get_fd();
+	if (u2mfn_fd < 0)
+		return -1;
+	ring = (struct vchan_interface *) u2mfn_alloc_kpage_with_fd (u2mfn_fd);
 
 	if (ring == MAP_FAILED)
 		return -1;
 
-	if (u2mfn_get_last_mfn (&mfn) < 0)
+	if (u2mfn_get_last_mfn_with_fd (u2mfn_fd, &mfn) < 0)
 		return -1;
 #endif
 
diff --git a/vchan/io.c b/vchan/io.c
index 5d32b4e9..d6b7ac92 100644
--- a/vchan/io.c
+++ b/vchan/io.c
@@ -129,7 +129,7 @@ int libvchan_wait(struct libvchan *ctrl)
         may write less data than requested;
         returns the amount of data processed, -1 on error or peer close
 */        
-int libvchan_write(struct libvchan *ctrl, char *data, int size)
+int libvchan_write(struct libvchan *ctrl, const char *data, int size)
 {
 	int avail, avail_contig;
 	int real_idx;
diff --git a/vchan/libvchan.h b/vchan/libvchan.h
index 6b19b2fa..4307346d 100644
--- a/vchan/libvchan.h
+++ b/vchan/libvchan.h
@@ -78,7 +78,7 @@ struct libvchan *libvchan_server_init(int devno);
 struct libvchan *libvchan_client_init(int domain, int devno);
 
 int libvchan_server_handle_connected(struct libvchan *ctrl);
-int libvchan_write(struct libvchan *ctrl, char *data, int size);
+int libvchan_write(struct libvchan *ctrl, const char *data, int size);
 int libvchan_read(struct libvchan *ctrl, char *data, int size);
 int libvchan_wait(struct libvchan *ctrl);
 int libvchan_close(struct libvchan *ctrl);
diff --git a/version_dom0 b/version_dom0
index 1bb41e63..3e3c2f1e 100644
--- a/version_dom0
+++ b/version_dom0
@@ -1 +1 @@
-2.0.36
+2.1.1
diff --git a/version_vm b/version_vm
index c8a481c8..3e3c2f1e 100644
--- a/version_vm
+++ b/version_vm
@@ -1 +1 @@
-1.7.46
+2.1.1
diff --git a/vm-init.d/qubes_core b/vm-init.d/qubes_core
index c5fe5d2a..4830587b 100755
--- a/vm-init.d/qubes_core
+++ b/vm-init.d/qubes_core
@@ -17,6 +17,8 @@ start()
 
 	# Set permissions to /proc/xen/xenbus, so normal user can use xenstore-read
 	chmod 666 /proc/xen/xenbus
+	# Set permissions to files needed to listen at vchan
+	chmod 666 /proc/u2mfn /dev/xen/evtchn
 
 	mkdir -p /var/run/xen-hotplug
 
diff --git a/vm-systemd/qubes-sysinit.sh b/vm-systemd/qubes-sysinit.sh
index b0544071..f0b098a7 100755
--- a/vm-systemd/qubes-sysinit.sh
+++ b/vm-systemd/qubes-sysinit.sh
@@ -25,6 +25,8 @@ mkdir -p /var/run/xen-hotplug
 
 # Set permissions to /proc/xen/xenbus, so normal user can use xenstore-read
 chmod 666 /proc/xen/xenbus
+# Set permissions to files needed to listen at vchan
+chmod 666 /proc/u2mfn /dev/xen/evtchn
 
 # Set default services depending on VM type
 TYPE=`$XS_READ qubes_vm_type 2> /dev/null`