dom0: vchan version for stubdom

vchan/Makefile.stubdom

@@ -0,0 +1,36 @@
+#
+# The Qubes OS Project, http://www.qubes-os.org
+#
+# Copyright (C) 2012  Marek Marczykowski <marmarek@invisiblethingslab.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+
+# Assume it is placed as xen-root/tools/vchan
+
+XEN_ROOT = ../..
+include $(XEN_ROOT)/tools/Rules.mk
+
+CFLAGS+=-Wall -I$(XEN_ROOT)/tools/libxc -DCONFIG_STUBDOM
+all: libvchan.a
+
+libvchan.a: init.o io.o
+	    $(AR) rc $@ $^
+
+clean:
+	rm -f *.o *so *~ client server node node-select
+	
+		

vchan/init.c

@@ -19,6 +19,9 @@
  *
  */
 
+#include <sys/types.h>
+#include <sys/unistd.h>
+#include <sys/stat.h>
 #include <sys/mman.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -29,25 +32,38 @@
 #include <xenctrl.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <mm.h>
 #include "libvchan.h"
+#ifndef CONFIG_STUBDOM
 #include "../u2mfn/u2mfnlib.h"
+#endif
 
 static int ring_init(struct libvchan *ctrl)
 {
-	int u2mfn = open("/proc/u2mfn", O_RDONLY);
 	int mfn;
 	struct vchan_interface *ring;
+#ifdef CONFIG_STUBDOM
+	ring = (struct vchan_interface *) memalign(XC_PAGE_SIZE, sizeof(*ring));
+
+	if (!ring)
+		return -1;
+
+
+	mfn = virtual_to_mfn(ring);
+#else
+	int u2mfn = open("/proc/u2mfn", O_RDONLY);
 	ring = (struct vchan_interface *) u2mfn_alloc_kpage ();
 
 	if (ring == MAP_FAILED)
 		return -1;
 
-	ctrl->ring = ring;
 	if (u2mfn_get_last_mfn (&mfn) < 0)
 		return -1;
-
-	ctrl->ring_ref = mfn;
 	close(u2mfn);
+#endif
+
+	ctrl->ring = ring;
+	ctrl->ring_ref = mfn;
 	ring->cons_in = ring->prod_in = ring->cons_out = ring->prod_out =
 	    0;
 	ring->server_closed = ring->client_closed = 0;
@@ -65,13 +81,18 @@ static int server_interface_init(struct libvchan *ctrl, int devno)
 	struct xs_handle *xs;
 	char buf[64];
 	char ref[16];
+	/* XXX temp hack begin */
+	char *domid_s;
+	int domid = 0;
+	unsigned int len;
+	/* XXX temp hack end */
 #ifdef XENCTRL_HAS_XC_INTERFACE
     xc_evtchn *evfd;
 #else
 	int evfd;
 #endif
 	evtchn_port_or_error_t port;
-	xs = xs_domain_open();
+	xs = xs_daemon_open();
 	if (!xs) {
 		return ret;
 	}
@@ -90,20 +111,41 @@ static int server_interface_init(struct libvchan *ctrl, int devno)
 	if (port < 0)
 		goto fail2;
 	ctrl->evport = port;
+	ctrl->devno = devno;
+
+	// stubdom debug HACK XXX
+	domid_s = xs_read(xs, 0, "domid", &len);
+	if (domid_s)
+		domid = atoi(domid_s);
+
 	snprintf(ref, sizeof ref, "%d", ctrl->ring_ref);
 	snprintf(buf, sizeof buf, "device/vchan/%d/ring-ref", devno);
 	if (!xs_write(xs, 0, buf, ref, strlen(ref)))
+#ifdef CONFIG_STUBDOM
+		// TEMP HACK XXX FIXME goto fail2;
+		fprintf(stderr, "xenstore-write /local/domain/%d/%s %s\n", domid, buf, ref);
+#else
 		goto fail2;
+#endif
 	snprintf(ref, sizeof ref, "%d", ctrl->evport);
 	snprintf(buf, sizeof buf, "device/vchan/%d/event-channel", devno);
 	if (!xs_write(xs, 0, buf, ref, strlen(ref)))
+#ifdef CONFIG_STUBDOM
+		// TEMP HACK XXX FIXME goto fail2;
+		fprintf(stderr, "xenstore-write /local/domain/%d/%s %s\n", domid, buf, ref);
+#else
 		goto fail2;
+#endif
+		// do not block in stubdom - libvchan_server_handle_connected will be
+		// called on first input
+#ifndef CONFIG_STUBDOM
         // wait for the peer to arrive
 	if (xc_evtchn_pending(evfd) == -1)
 		goto fail2;
         xc_evtchn_unmask(ctrl->evfd, ctrl->evport);
 	snprintf(buf, sizeof buf, "device/vchan/%d", devno);
 	xs_rm(xs, 0, buf);
+#endif
 
 	ret = 0;
       fail2:
@@ -130,7 +172,7 @@ static int server_interface_init(struct libvchan *ctrl, int devno)
 
 /**
         Run in AppVM (any domain).
-        Sleeps until the connection is established.
+        Sleeps until the connection is established. (unless in stubdom)
         \param devno something like a well-known port.
         \returns NULL on failure, handle on success
 */
@@ -156,6 +198,39 @@ struct libvchan *libvchan_server_init(int devno)
 	return ctrl;
 }
 
+int libvchan_server_handle_connected(struct libvchan *ctrl)
+{
+	struct xs_handle *xs;
+	char buf[64];
+	int ret = -1;
+	int libvchan_fd;
+	fd_set rfds;
+
+	xs = xs_daemon_open();
+	if (!xs) {
+		return ret;
+	}
+	// clear the pending flag
+	xc_evtchn_pending(ctrl->evfd);
+
+	snprintf(buf, sizeof buf, "device/vchan/%d", ctrl->devno);
+	xs_rm(xs, 0, buf);
+
+	ret = 0;
+
+#if 0
+fail2:
+	if (ret)
+#ifdef XENCTRL_HAS_XC_INTERFACE
+        xc_evtchn_close(ctrl->evfd);
+#else
+		close(ctrl->evfd);
+#endif
+#endif
+	xs_daemon_close(xs);
+	return ret;
+}
+
 /**
         retrieves ring-ref and event-channel numbers from xenstore (if
         they don't exist, return error, because nobody seems to listen);

vchan/io.c

@@ -22,6 +22,8 @@
 #include "libvchan.h"
 #include <xenctrl.h>
 #include <string.h>
+#include <errno.h>
+#include <sys/select.h>
 /**
         \return How much data is immediately available for reading
 */
@@ -67,7 +69,24 @@ int libvchan_is_eof(struct libvchan *ctrl)
 int libvchan_wait(struct libvchan *ctrl)
 {
 	int ret;
+#ifndef CONFIG_STUBDOM
 	ret = xc_evtchn_pending(ctrl->evfd);
+#else
+	int vchan_fd = libvchan_fd_for_select(ctrl);
+	fd_set rfds;
+
+	libvchan_prepare_to_select(ctrl);
+	while ((ret = xc_evtchn_pending(ctrl->evfd)) < 0) {
+        FD_ZERO(&rfds);
+        FD_SET(0, &rfds);
+        FD_SET(vchan_fd, &rfds);
+        ret = select(vchan_fd + 1, &rfds, NULL, NULL, NULL);
+        if (ret < 0 && errno != EINTR) {
+            perror("select");
+			return ret;
+        }
+	}
+#endif
 	if (ret!=-1 && xc_evtchn_unmask(ctrl->evfd, ctrl->evport))
 		return -1;
 	if (ret!=-1 && libvchan_is_eof(ctrl))

vchan/libvchan.h

@@ -19,6 +19,9 @@
  *
  */
 
+#ifndef _LIBVCHAN_H
+#define _LIBVCHAN_H
+
 #include <stdint.h>
 #include <xenctrl.h>
 typedef uint32_t VCHAN_RING_IDX;
@@ -44,6 +47,7 @@ struct libvchan {
 	int evfd;
 #endif
 	int evport;
+	int devno;
 	VCHAN_RING_IDX *wr_cons, *wr_prod, *rd_cons, *rd_prod;
 	char *rd_ring, *wr_ring;
 	int rd_ring_size, wr_ring_size;
@@ -51,6 +55,7 @@ struct libvchan {
 };
 
 struct libvchan *libvchan_server_init(int devno);
+int libvchan_server_handle_connected(struct libvchan *ctrl);
 
 struct libvchan *libvchan_client_init(int domain, int devno);
 
@@ -63,3 +68,5 @@ int libvchan_fd_for_select(struct libvchan *ctrl);
 int libvchan_is_eof(struct libvchan *ctrl);
 int libvchan_data_ready(struct libvchan *ctrl);
 int libvchan_buffer_space(struct libvchan *ctrl);
+
+#endif /* _LIBVCHAN_H */