stubdom: use PVFB so as to e.g. permit SDL display

This adds support in ioemu for PVFB frontend as stubdomain display.
This permits for instance to use SDL in dom0 to perform the eventual
display.

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

7 files changed, 311 insertions, 29 deletions

diff --git a/extras/mini-os/fbfront.c b/extras/mini-os/fbfront.c
index bbe49b92a5..4f5041ab69 100644
--- a/extras/mini-os/fbfront.c
+++ b/extras/mini-os/fbfront.c
@@ -31,13 +31,6 @@ struct kbdfront_dev {
     char *nodename;
     char *backend;
 
-    char *data;
-    int width;
-    int height;
-    int depth;
-    int line_length;
-    int mem_length;
-
 #ifdef HAVE_LIBC
     int fd;
 #endif
@@ -316,7 +309,10 @@ struct fbfront_dev *init_fbfront(char *nodename, void *data, int width, int heig
     for (i = 0; mapped < mem_length && i < max_pd; i++) {
         unsigned long *pd = (unsigned long *) alloc_page();
         for (j = 0; mapped < mem_length && j < PAGE_SIZE / sizeof(unsigned long); j++) {
-            pd[j] = virt_to_mfn((unsigned long) data + mapped);
+            /* Trigger CoW */
+            * ((char *)data + mapped) = 0;
+            barrier();
+            pd[j] = virtual_to_mfn((unsigned long) data + mapped);
             mapped += PAGE_SIZE;
         }
         for ( ; j < PAGE_SIZE / sizeof(unsigned long); j++)
diff --git a/extras/mini-os/include/fbfront.h b/extras/mini-os/include/fbfront.h
index 502f0330a2..fa98942e76 100644
--- a/extras/mini-os/include/fbfront.h
+++ b/extras/mini-os/include/fbfront.h
@@ -14,6 +14,9 @@
 #ifndef KEY_Q
 #define KEY_Q 16
 #endif
+#ifndef KEY_MAX
+#define KEY_MAX 0x1ff
+#endif
 
 
 struct kbdfront_dev;
diff --git a/stubdom/README b/stubdom/README
index 4b9bef6b19..d4e1664b4f 100644
--- a/stubdom/README
+++ b/stubdom/README
@@ -6,39 +6,78 @@ Then make install to install the result.
 
 Also, run make and make install in $XEN_ROOT/tools/fs-back
 
-To run
-======
-
-mkdir -p /exports/usr/share/qemu
-ln -s /usr/share/qemu/keymaps /exports/usr/share/qemu
-/usr/sbin/fs-backend &
-
+General Configuration
+=====================
 
 In your HVM config "hvmconfig",
 
-- use VNC, set vnclisten to "172.30.206.1" for instance.  Do not use a host name
-as Mini-OS does not have a name resolver.  Do not use 127.0.0.1 since then you
-will not be able to connect to it.
-
-vnc = 1
-vnclisten = "172.30.206.1"
-
 - use /usr/lib/xen/bin/stubdom-dm as dm script
 
 device_model = '/usr/lib/xen/bin/stubdom-dm'
 
 - comment the disk statement:
+
 #disk = [  'file:/tmp/install.iso,hdc:cdrom,r', 'phy:/dev/sda6,hda,w', 'file:/tmp/test,hdb,r' ]
 
-Create /etc/xen/stubdom-hvmconfig (where "hvmconfig" is your HVM guest domain
-name) with
+
+Create /etc/xen/stubdom-hvmconfig (where "hvmconfig" is the name of your HVM
+guest) with
 
 kernel = "/usr/lib/xen/boot/stubdom.gz"
-vif = [ 'ip=172.30.206.1', 'ip=10.0.1.1,mac=aa:00:00:12:23:34']
+vif = [ '', 'ip=10.0.1.1,mac=aa:00:00:12:23:34']
 disk = [  'file:/tmp/install.iso,hdc:cdrom,r', 'phy:/dev/sda6,hda,w', 'file:/tmp/test,hdb,r' ]
 
 where
-- 172.30.206.1 is the IP for vnc,
+- the first vif ('') is reserved for VNC (see below)
 - 'ip=10.0.1.1,mac= etc...' is the same net configuration as in the hvmconfig
 script,
 - and disk = is the same block configuration as in the hvmconfig script.
+
+Display Configuration
+=====================
+
+There are three posibilities
+
+* Using SDL
+
+In hvmconfig, disable vnc:
+
+vnc = 0
+
+In stubdom-hvmconfig, set a vfb:
+
+vfb = [ 'type=sdl' ]
+
+* Using a VNC server in the stub domain
+
+In hvmconfig, set vnclisten to "172.30.206.1" for instance.  Do not use a host
+name as Mini-OS does not have a name resolver.  Do not use 127.0.0.1 since then
+you will not be able to connect to it.
+
+vnc = 1
+vnclisten = "172.30.206.1"
+
+In stubdom-hvmconfig, fill the reserved vif with the same IP, for instance:
+
+vif = [ 'ip=172.30.206.1', 'ip=10.0.1.1,mac=aa:00:00:12:23:34']
+
+* Using a VNC server in dom0
+
+In hvmconfig, disable vnc:
+
+vnc = 0
+
+In stubdom-hvmconfig, set a vfb:
+
+vfb = [ 'type=vnc' ]
+
+and any other parameter as wished.
+
+To run
+======
+
+mkdir -p /exports/usr/share/qemu
+ln -s /usr/share/qemu/keymaps /exports/usr/share/qemu
+/usr/sbin/fs-backend &
+
+xm create hvmconfig
diff --git a/tools/ioemu/hw/xenfb.c b/tools/ioemu/hw/xenfb.c
index ea4ea14db2..e2f181126e 100644
--- a/tools/ioemu/hw/xenfb.c
+++ b/tools/ioemu/hw/xenfb.c
@@ -19,6 +19,12 @@
 
 #include "xenfb.h"
 
+#ifdef CONFIG_STUBDOM
+#include <semaphore.h>
+#include <sched.h>
+#include <fbfront.h>
+#endif
+
 #ifndef BTN_LEFT
 #define BTN_LEFT 0x110 /* from <linux/input.h> */
 #endif
@@ -1124,12 +1130,10 @@ static void xenfb_guest_copy(struct xenfb *xenfb, int x, int y, int w, int h)
     dpy_update(xenfb->ds, x, y, w, h);
 }
 
-/* QEMU display state changed, so refresh the framebuffer copy */
-/* XXX - can we optimize this, or the next func at all ? */ 
+/* Periodic update of display, no need for any in our case */
 static void xenfb_update(void *opaque)
 {
     struct xenfb *xenfb = opaque;
-    xenfb_guest_copy(xenfb, 0, 0, xenfb->width, xenfb->height);
 }
 
 /* QEMU display state changed, so refresh the framebuffer copy */
@@ -1169,6 +1173,206 @@ static int xenfb_register_console(struct xenfb *xenfb) {
         return 0;
 }
 
+#ifdef CONFIG_STUBDOM
+static struct semaphore kbd_sem = __SEMAPHORE_INITIALIZER(kbd_sem, 0);
+static struct kbdfront_dev *kbd_dev;
+static char *kbd_path, *fb_path;
+
+static unsigned char linux2scancode[KEY_MAX + 1];
+
+#define WIDTH 1024
+#define HEIGHT 768
+#define DEPTH 32
+#define LINESIZE (1280 * (DEPTH / 8))
+#define MEMSIZE (LINESIZE * HEIGHT)
+
+int xenfb_connect_vkbd(const char *path)
+{
+    kbd_path = strdup(path);
+    return 0;
+}
+
+int xenfb_connect_vfb(const char *path)
+{
+    fb_path = strdup(path);
+    return 0;
+}
+
+static void xenfb_pv_update(DisplayState *s, int x, int y, int w, int h)
+{
+    struct fbfront_dev *fb_dev = s->opaque;
+    fbfront_update(fb_dev, x, y, w, h);
+}
+
+static void xenfb_pv_resize(DisplayState *s, int w, int h)
+{
+    struct fbfront_dev *fb_dev = s->opaque;
+    fprintf(stderr,"resize to %dx%d required\n", w, h);
+    s->width = w;
+    s->height = h;
+    /* TODO: send resize event if supported */
+    memset(s->data, 0, MEMSIZE);
+    fbfront_update(fb_dev, 0, 0, WIDTH, HEIGHT);
+}
+
+static void xenfb_pv_colourdepth(DisplayState *s, int depth)
+{
+    /* TODO: send redepth event if supported */
+    fprintf(stderr,"redepth to %d required\n", depth);
+}
+
+static void xenfb_kbd_handler(void *opaque)
+{
+#define KBD_NUM_BATCH 64
+    union xenkbd_in_event buf[KBD_NUM_BATCH];
+    int n, i;
+    DisplayState *s = opaque;
+    static int buttons;
+    static int x, y, z;
+
+    n = kbdfront_receive(kbd_dev, buf, KBD_NUM_BATCH);
+    for (i = 0; i < n; i++) {
+        switch (buf[i].type) {
+
+            case XENKBD_TYPE_MOTION:
+                fprintf(stderr, "FB backend sent us relative mouse motion event!\n");
+                break;
+
+            case XENKBD_TYPE_POS:
+            {
+                int new_x = buf[i].pos.abs_x;
+                int new_y = buf[i].pos.abs_y;
+                int new_z = buf[i].pos.abs_z;
+                if (new_x >= s->width)
+                    new_x = s->width - 1;
+                if (new_y >= s->height)
+                    new_y = s->height - 1;
+                if (kbd_mouse_is_absolute()) {
+                    kbd_mouse_event(
+                            new_x * 0x7FFF / (s->width - 1),
+                            new_y * 0x7FFF / (s->height - 1),
+                            new_z,
+                            buttons);
+                } else {
+                    kbd_mouse_event(
+                            new_x - x,
+                            new_y - y,
+                            new_z - z,
+                            buttons);
+                }
+                x = new_x;
+                y = new_y;
+                z = new_z;
+                break;
+            }
+
+            case XENKBD_TYPE_KEY:
+            {
+                int keycode = buf[i].key.keycode;
+                int button = 0;
+
+                if (keycode == BTN_LEFT)
+                    button = MOUSE_EVENT_LBUTTON;
+                else if (keycode == BTN_RIGHT)
+                    button = MOUSE_EVENT_RBUTTON;
+                else if (keycode == BTN_MIDDLE)
+                    button = MOUSE_EVENT_MBUTTON;
+
+                if (button) {
+                    if (buf[i].key.pressed)
+                        buttons |=  button;
+                    else
+                        buttons &= ~button;
+                    if (kbd_mouse_is_absolute())
+                        kbd_mouse_event(
+                                x * 0x7FFF / s->width,
+                                y * 0x7FFF / s->height,
+                                z,
+                                buttons);
+                    else
+                        kbd_mouse_event(0, 0, 0, buttons);
+                } else {
+                    int scancode = linux2scancode[keycode];
+                    if (!scancode) {
+                        fprintf(stderr, "Can't convert keycode %x to scancode\n", keycode);
+                        break;
+                    }
+                    if (scancode & 0x80) {
+                        kbd_put_keycode(0xe0);
+                        scancode &= 0x7f;
+                    }
+                    if (!buf[i].key.pressed)
+                        scancode |= 0x80;
+                    kbd_put_keycode(scancode);
+                }
+                break;
+            }
+        }
+    }
+}
+
+static void xenfb_pv_refresh(DisplayState *ds)
+{
+    vga_hw_update();
+}
+
+static void kbdfront_thread(void *p)
+{
+    int scancode, keycode;
+    kbd_dev = init_kbdfront(p, 1);
+    if (!kbd_dev) {
+        fprintf(stderr,"can't open keyboard\n");
+        exit(1);
+    }
+    up(&kbd_sem);
+    for (scancode = 0; scancode < 128; scancode++) {
+        keycode = atkbd_set2_keycode[atkbd_unxlate_table[scancode]];
+        linux2scancode[keycode] = scancode;
+        keycode = atkbd_set2_keycode[atkbd_unxlate_table[scancode] | 0x80];
+        linux2scancode[keycode] = scancode | 0x80;
+    }
+}
+
+int xenfb_pv_display_init(DisplayState *ds)
+{
+    void *data;
+    struct fbfront_dev *fb_dev;
+    int kbd_fd;
+
+    if (!fb_path || !kbd_path)
+        return -1;
+
+    create_thread("kbdfront", kbdfront_thread, (void*) kbd_path);
+
+    data = qemu_memalign(PAGE_SIZE, VGA_RAM_SIZE);
+    fb_dev = init_fbfront(fb_path, data, WIDTH, HEIGHT, DEPTH, LINESIZE, MEMSIZE);
+    if (!fb_dev) {
+        fprintf(stderr,"can't open frame buffer\n");
+        exit(1);
+    }
+    free(fb_path);
+
+    down(&kbd_sem);
+    free(kbd_path);
+
+    kbd_fd = kbdfront_open(kbd_dev);
+    qemu_set_fd_handler(kbd_fd, xenfb_kbd_handler, NULL, ds);
+
+    ds->data = data;
+    ds->linesize = LINESIZE;
+    ds->depth = DEPTH;
+    ds->bgr = 0;
+    ds->width = WIDTH;
+    ds->height = HEIGHT;
+    ds->dpy_update = xenfb_pv_update;
+    ds->dpy_resize = xenfb_pv_resize;
+    ds->dpy_colourdepth = NULL; //xenfb_pv_colourdepth;
+    ds->dpy_refresh = xenfb_pv_refresh;
+    ds->opaque = fb_dev;
+    return 0;
+}
+#endif
+
 /*
  * Local variables:
  *  c-indent-level: 8
diff --git a/tools/ioemu/vl.c b/tools/ioemu/vl.c
index f9a575043d..aaecb286a9 100644
--- a/tools/ioemu/vl.c
+++ b/tools/ioemu/vl.c
@@ -7831,6 +7831,10 @@ int main(int argc, char **argv)
     init_ioports();
 
     /* terminal init */
+#ifdef CONFIG_STUBDOM
+    if (xenfb_pv_display_init(ds) == 0) {
+    } else
+#endif
     if (nographic) {
         dumb_display_init(ds);
     } else if (vnc_display != NULL || vncunused != 0) {
diff --git a/tools/ioemu/vl.h b/tools/ioemu/vl.h
index 0c5a9da97f..5c421cff9c 100644
--- a/tools/ioemu/vl.h
+++ b/tools/ioemu/vl.h
@@ -1527,6 +1527,11 @@ int xenstore_unsubscribe_from_hotplug_status(struct xs_handle *handle,
 int xenstore_vm_write(int domid, char *key, char *val);
 char *xenstore_vm_read(int domid, char *key, unsigned int *len);
 
+/* xenfb.c */
+int xenfb_pv_display_init(DisplayState *ds);
+int xenfb_connect_vkbd(const char *path);
+int xenfb_connect_vfb(const char *path);
+
 /* helper2.c */
 extern long time_offset;
 void timeoffset_get(void);
diff --git a/tools/ioemu/xenstore.c b/tools/ioemu/xenstore.c
index 843a10e875..e1c253221b 100644
--- a/tools/ioemu/xenstore.c
+++ b/tools/ioemu/xenstore.c
@@ -238,6 +238,37 @@ void xenstore_parse_domain_config(int domid)
         }
     }
 
+#ifdef CONFIG_STUBDOM
+    if (pasprintf(&buf, "%s/device/vkbd", path) == -1)
+        goto out;
+
+    free(e);
+    e = xs_directory(xsh, XBT_NULL, buf, &num);
+
+    if (e) {
+        for (i = 0; i < num; i++) {
+            if (pasprintf(&buf, "%s/device/vkbd/%s", path, e[i]) == -1)
+                continue;
+            xenfb_connect_vkbd(buf);
+        }
+    }
+
+    if (pasprintf(&buf, "%s/device/vfb", path) == -1)
+        goto out;
+
+    free(e);
+    e = xs_directory(xsh, XBT_NULL, buf, &num);
+
+    if (e) {
+        for (i = 0; i < num; i++) {
+            if (pasprintf(&buf, "%s/device/vfb/%s", path, e[i]) == -1)
+                continue;
+            xenfb_connect_vfb(buf);
+        }
+    }
+#endif
+
+
     /* Set a watch for log-dirty requests from the migration tools */
     if (pasprintf(&buf, "/local/domain/0/device-model/%u/logdirty/next-active",
                   domid) != -1) {