xen: add framebuffer backend driver (Gerd Hoffmann)

This patch adds a frsamebuffer (and kbd+mouse) backend driver.  It
it based on current xen-unstable code.  It has been changed to make
use of the common backend driver code.  It also has been changed to
compile with xen headers older than release 3.3

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7222 c046a42c-6fe2-441c-8c8c-71466251a162

3 files changed, 1022 insertions, 0 deletions

diff --git a/hw/xen_backend.h b/hw/xen_backend.h
index 4744713ff2..e9a4e2dd2d 100644
--- a/hw/xen_backend.h
+++ b/hw/xen_backend.h
@@ -85,5 +85,9 @@ void xen_be_printf(struct XenDevice *xendev, int msg_level, const char *fmt, ...
 
 /* actual backend drivers */
 extern struct XenDevOps xen_console_ops;      /* xen_console.c     */
+extern struct XenDevOps xen_kbdmouse_ops;     /* xen_framebuffer.c */
+extern struct XenDevOps xen_framebuffer_ops;  /* xen_framebuffer.c */
+
+void xen_init_display(int domid);
 
 #endif /* QEMU_HW_XEN_BACKEND_H */
diff --git a/hw/xen_machine_pv.c b/hw/xen_machine_pv.c
index 93ab312d86..1f0b3ec8fd 100644
--- a/hw/xen_machine_pv.c
+++ b/hw/xen_machine_pv.c
@@ -57,6 +57,11 @@ static void xen_init_pv(ram_addr_t ram_size, int vga_ram_size,
         exit(1);
     }
     xen_be_register("console", &xen_console_ops);
+    xen_be_register("vkbd", &xen_kbdmouse_ops);
+    xen_be_register("vfb", &xen_framebuffer_ops);
+
+    /* setup framebuffer */
+    xen_init_display(xen_domid);
 }
 
 QEMUMachine xenpv_machine = {
diff --git a/hw/xenfb.c b/hw/xenfb.c
new file mode 100644
index 0000000000..d93844122a
--- /dev/null
+++ b/hw/xenfb.c
@@ -0,0 +1,1013 @@
+/*
+ *  xen paravirt framebuffer backend
+ *
+ *  Copyright IBM, Corp. 2005-2006
+ *  Copyright Red Hat, Inc. 2006-2008
+ *
+ *  Authors:
+ *       Anthony Liguori <aliguori@us.ibm.com>,
+ *       Markus Armbruster <armbru@redhat.com>,
+ *       Daniel P. Berrange <berrange@redhat.com>,
+ *       Pat Campbell <plc@novell.com>,
+ *       Gerd Hoffmann <kraxel@redhat.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; under version 2 of the License.
+ *
+ *  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.
+ */
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include <xs.h>
+#include <xenctrl.h>
+#include <xen/event_channel.h>
+#include <xen/io/xenbus.h>
+#include <xen/io/fbif.h>
+#include <xen/io/kbdif.h>
+#include <xen/io/protocols.h>
+
+#include "hw.h"
+#include "sysemu.h"
+#include "console.h"
+#include "qemu-char.h"
+#include "xen_backend.h"
+
+#ifndef BTN_LEFT
+#define BTN_LEFT 0x110 /* from <linux/input.h> */
+#endif
+
+/* -------------------------------------------------------------------- */
+
+struct common {
+    struct XenDevice  xendev;  /* must be first */
+    void              *page;
+    DisplayState      *ds;
+};
+
+struct XenInput {
+    struct common c;
+    int abs_pointer_wanted; /* Whether guest supports absolute pointer */
+    int button_state;       /* Last seen pointer button state */
+    int extended;
+    QEMUPutMouseEntry *qmouse;
+};
+
+#define UP_QUEUE 8
+
+struct XenFB {
+    struct common     c;
+    size_t            fb_len;
+    int               row_stride;
+    int               depth;
+    int               width;
+    int               height;
+    int               offset;
+    void              *pixels;
+    int               fbpages;
+    int               feature_update;
+    int               refresh_period;
+    int               bug_trigger;
+    int               have_console;
+    int               do_resize;
+
+    struct {
+	int x,y,w,h;
+    } up_rects[UP_QUEUE];
+    int               up_count;
+    int               up_fullscreen;
+};
+
+/* -------------------------------------------------------------------- */
+
+static int common_bind(struct common *c)
+{
+    int mfn;
+
+    if (xenstore_read_fe_int(&c->xendev, "page-ref", &mfn) == -1)
+	return -1;
+    if (xenstore_read_fe_int(&c->xendev, "event-channel", &c->xendev.remote_port) == -1)
+	return -1;
+
+    c->page = xc_map_foreign_range(xen_xc, c->xendev.dom,
+				   XC_PAGE_SIZE,
+				   PROT_READ | PROT_WRITE, mfn);
+    if (c->page == NULL)
+	return -1;
+
+    xen_be_bind_evtchn(&c->xendev);
+    xen_be_printf(&c->xendev, 1, "ring mfn %d, remote-port %d, local-port %d\n",
+		  mfn, c->xendev.remote_port, c->xendev.local_port);
+
+    return 0;
+}
+
+static void common_unbind(struct common *c)
+{
+    xen_be_unbind_evtchn(&c->xendev);
+    if (c->page) {
+	munmap(c->page, XC_PAGE_SIZE);
+	c->page = NULL;
+    }
+}
+
+/* -------------------------------------------------------------------- */
+
+#if 0
+/*
+ * These two tables are not needed any more, but left in here
+ * intentionally as documentation, to show how scancode2linux[]
+ * was generated.
+ *
+ * Tables to map from scancode to Linux input layer keycode.
+ * Scancodes are hardware-specific.  These maps assumes a
+ * standard AT or PS/2 keyboard which is what QEMU feeds us.
+ */
+const unsigned char atkbd_set2_keycode[512] = {
+
+     0, 67, 65, 63, 61, 59, 60, 88,  0, 68, 66, 64, 62, 15, 41,117,
+     0, 56, 42, 93, 29, 16,  2,  0,  0,  0, 44, 31, 30, 17,  3,  0,
+     0, 46, 45, 32, 18,  5,  4, 95,  0, 57, 47, 33, 20, 19,  6,183,
+     0, 49, 48, 35, 34, 21,  7,184,  0,  0, 50, 36, 22,  8,  9,185,
+     0, 51, 37, 23, 24, 11, 10,  0,  0, 52, 53, 38, 39, 25, 12,  0,
+     0, 89, 40,  0, 26, 13,  0,  0, 58, 54, 28, 27,  0, 43,  0, 85,
+     0, 86, 91, 90, 92,  0, 14, 94,  0, 79,124, 75, 71,121,  0,  0,
+    82, 83, 80, 76, 77, 72,  1, 69, 87, 78, 81, 74, 55, 73, 70, 99,
+
+      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    217,100,255,  0, 97,165,  0,  0,156,  0,  0,  0,  0,  0,  0,125,
+    173,114,  0,113,  0,  0,  0,126,128,  0,  0,140,  0,  0,  0,127,
+    159,  0,115,  0,164,  0,  0,116,158,  0,150,166,  0,  0,  0,142,
+    157,  0,  0,  0,  0,  0,  0,  0,155,  0, 98,  0,  0,163,  0,  0,
+    226,  0,  0,  0,  0,  0,  0,  0,  0,255, 96,  0,  0,  0,143,  0,
+      0,  0,  0,  0,  0,  0,  0,  0,  0,107,  0,105,102,  0,  0,112,
+    110,111,108,112,106,103,  0,119,  0,118,109,  0, 99,104,119,  0,
+
+};
+
+const unsigned char atkbd_unxlate_table[128] = {
+
+      0,118, 22, 30, 38, 37, 46, 54, 61, 62, 70, 69, 78, 85,102, 13,
+     21, 29, 36, 45, 44, 53, 60, 67, 68, 77, 84, 91, 90, 20, 28, 27,
+     35, 43, 52, 51, 59, 66, 75, 76, 82, 14, 18, 93, 26, 34, 33, 42,
+     50, 49, 58, 65, 73, 74, 89,124, 17, 41, 88,  5,  6,  4, 12,  3,
+     11,  2, 10,  1,  9,119,126,108,117,125,123,107,115,116,121,105,
+    114,122,112,113,127, 96, 97,120,  7, 15, 23, 31, 39, 47, 55, 63,
+     71, 79, 86, 94,  8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 87,111,
+     19, 25, 57, 81, 83, 92, 95, 98, 99,100,101,103,104,106,109,110
+
+};
+#endif
+
+/*
+ * for (i = 0; i < 128; i++) {
+ *     scancode2linux[i] = atkbd_set2_keycode[atkbd_unxlate_table[i]];
+ *     scancode2linux[i | 0x80] = atkbd_set2_keycode[atkbd_unxlate_table[i] | 0x80];
+ * }
+ */
+static const unsigned char scancode2linux[512] = {
+      0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
+     16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+     32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
+     48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
+     64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
+     80, 81, 82, 83, 99,  0, 86, 87, 88,117,  0,  0, 95,183,184,185,
+      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+     93,  0,  0, 89,  0,  0, 85, 91, 90, 92,  0, 94,  0,124,121,  0,
+
+      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    165,  0,  0,  0,  0,  0,  0,  0,  0,163,  0,  0, 96, 97,  0,  0,
+    113,140,164,  0,166,  0,  0,  0,  0,  0,255,  0,  0,  0,114,  0,
+    115,  0,150,  0,  0, 98,255, 99,100,  0,  0,  0,  0,  0,  0,  0,
+      0,  0,  0,  0,  0,119,119,102,103,104,  0,105,112,106,118,107,
+    108,109,110,111,  0,  0,  0,  0,  0,  0,  0,125,126,127,116,142,
+      0,  0,  0,143,  0,217,156,173,128,159,158,157,155,226,  0,112,
+      0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+};
+
+/* Send an event to the keyboard frontend driver */
+static int xenfb_kbd_event(struct XenInput *xenfb,
+			   union xenkbd_in_event *event)
+{
+    struct xenkbd_page *page = xenfb->c.page;
+    uint32_t prod;
+
+    if (xenfb->c.xendev.be_state != XenbusStateConnected)
+	return 0;
+    if (!page)
+        return 0;
+
+    prod = page->in_prod;
+    if (prod - page->in_cons == XENKBD_IN_RING_LEN) {
+	errno = EAGAIN;
+	return -1;
+    }
+
+    xen_mb();		/* ensure ring space available */
+    XENKBD_IN_RING_REF(page, prod) = *event;
+    xen_wmb();		/* ensure ring contents visible */
+    page->in_prod = prod + 1;
+    return xen_be_send_notify(&xenfb->c.xendev);
+}
+
+/* Send a keyboard (or mouse button) event */
+static int xenfb_send_key(struct XenInput *xenfb, bool down, int keycode)
+{
+    union xenkbd_in_event event;
+
+    memset(&event, 0, XENKBD_IN_EVENT_SIZE);
+    event.type = XENKBD_TYPE_KEY;
+    event.key.pressed = down ? 1 : 0;
+    event.key.keycode = keycode;
+
+    return xenfb_kbd_event(xenfb, &event);
+}
+
+/* Send a relative mouse movement event */
+static int xenfb_send_motion(struct XenInput *xenfb,
+			     int rel_x, int rel_y, int rel_z)
+{
+    union xenkbd_in_event event;
+
+    memset(&event, 0, XENKBD_IN_EVENT_SIZE);
+    event.type = XENKBD_TYPE_MOTION;
+    event.motion.rel_x = rel_x;
+    event.motion.rel_y = rel_y;
+#if __XEN_LATEST_INTERFACE_VERSION__ >= 0x00030207
+    event.motion.rel_z = rel_z;
+#endif
+
+    return xenfb_kbd_event(xenfb, &event);
+}
+
+/* Send an absolute mouse movement event */
+static int xenfb_send_position(struct XenInput *xenfb,
+			       int abs_x, int abs_y, int z)
+{
+    union xenkbd_in_event event;
+
+    memset(&event, 0, XENKBD_IN_EVENT_SIZE);
+    event.type = XENKBD_TYPE_POS;
+    event.pos.abs_x = abs_x;
+    event.pos.abs_y = abs_y;
+#if __XEN_LATEST_INTERFACE_VERSION__ == 0x00030207
+    event.pos.abs_z = z;
+#endif
+#if __XEN_LATEST_INTERFACE_VERSION__ >= 0x00030208
+    event.pos.rel_z = z;
+#endif
+
+    return xenfb_kbd_event(xenfb, &event);
+}
+
+/*
+ * Send a key event from the client to the guest OS
+ * QEMU gives us a raw scancode from an AT / PS/2 style keyboard.
+ * We have to turn this into a Linux Input layer keycode.
+ *
+ * Extra complexity from the fact that with extended scancodes
+ * (like those produced by arrow keys) this method gets called
+ * twice, but we only want to send a single event. So we have to
+ * track the '0xe0' scancode state & collapse the extended keys
+ * as needed.
+ *
+ * Wish we could just send scancodes straight to the guest which
+ * already has code for dealing with this...
+ */
+static void xenfb_key_event(void *opaque, int scancode)
+{
+    struct XenInput *xenfb = opaque;
+    int down = 1;
+
+    if (scancode == 0xe0) {
+	xenfb->extended = 1;
+	return;
+    } else if (scancode & 0x80) {
+	scancode &= 0x7f;
+	down = 0;
+    }
+    if (xenfb->extended) {
+	scancode |= 0x80;
+	xenfb->extended = 0;
+    }
+    xenfb_send_key(xenfb, down, scancode2linux[scancode]);
+}
+
+/*
+ * Send a mouse event from the client to the guest OS
+ *
+ * The QEMU mouse can be in either relative, or absolute mode.
+ * Movement is sent separately from button state, which has to
+ * be encoded as virtual key events. We also don't actually get
+ * given any button up/down events, so have to track changes in
+ * the button state.
+ */
+static void xenfb_mouse_event(void *opaque,
+			      int dx, int dy, int dz, int button_state)
+{
+    struct XenInput *xenfb = opaque;
+    int dw = ds_get_width(xenfb->c.ds);
+    int dh = ds_get_height(xenfb->c.ds);
+    int i;
+
+    if (xenfb->abs_pointer_wanted)
+	xenfb_send_position(xenfb,
+			    dx * (dw - 1) / 0x7fff,
+			    dy * (dh - 1) / 0x7fff,
+			    dz);
+    else
+	xenfb_send_motion(xenfb, dx, dy, dz);
+
+    for (i = 0 ; i < 8 ; i++) {
+	int lastDown = xenfb->button_state & (1 << i);
+	int down = button_state & (1 << i);
+	if (down == lastDown)
+	    continue;
+
+	if (xenfb_send_key(xenfb, down, BTN_LEFT+i) < 0)
+	    return;
+    }
+    xenfb->button_state = button_state;
+}
+
+static int input_init(struct XenDevice *xendev)
+{
+    struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
+
+    if (!in->c.ds) {
+        xen_be_printf(xendev, 1, "ds not set (yet)\n");
+	return -1;
+    }
+
+    xenstore_write_be_int(xendev, "feature-abs-pointer", 1);
+    return 0;
+}
+
+static int input_connect(struct XenDevice *xendev)
+{
+    struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
+    int rc;
+
+    if (xenstore_read_fe_int(xendev, "request-abs-pointer",
+                             &in->abs_pointer_wanted) == -1)
+	in->abs_pointer_wanted = 0;
+
+    rc = common_bind(&in->c);
+    if (rc != 0)
+	return rc;
+
+    qemu_add_kbd_event_handler(xenfb_key_event, in);
+    in->qmouse = qemu_add_mouse_event_handler(xenfb_mouse_event, in,
+					      in->abs_pointer_wanted,
+					      "Xen PVFB Mouse");
+    return 0;
+}
+
+static void input_disconnect(struct XenDevice *xendev)
+{
+    struct XenInput *in = container_of(xendev, struct XenInput, c.xendev);
+
+    if (in->qmouse) {
+	qemu_remove_mouse_event_handler(in->qmouse);
+	in->qmouse = NULL;
+    }
+    qemu_add_kbd_event_handler(NULL, NULL);
+    common_unbind(&in->c);
+}
+
+static void input_event(struct XenDevice *xendev)
+{
+    struct XenInput *xenfb = container_of(xendev, struct XenInput, c.xendev);
+    struct xenkbd_page *page = xenfb->c.page;
+
+    /* We don't understand any keyboard events, so just ignore them. */
+    if (page->out_prod == page->out_cons)
+	return;
+    page->out_cons = page->out_prod;
+    xen_be_send_notify(&xenfb->c.xendev);
+}
+
+/* -------------------------------------------------------------------- */
+
+static void xenfb_copy_mfns(int mode, int count, unsigned long *dst, void *src)
+{
+    uint32_t *src32 = src;
+    uint64_t *src64 = src;
+    int i;
+
+    for (i = 0; i < count; i++)
+	dst[i] = (mode == 32) ? src32[i] : src64[i];
+}
+
+static int xenfb_map_fb(struct XenFB *xenfb)
+{
+    struct xenfb_page *page = xenfb->c.page;
+    char *protocol = xenfb->c.xendev.protocol;
+    int n_fbdirs;
+    unsigned long *pgmfns = NULL;
+    unsigned long *fbmfns = NULL;
+    void *map, *pd;
+    int mode, ret = -1;
+
+    /* default to native */
+    pd = page->pd;
+    mode = sizeof(unsigned long) * 8;
+
+    if (!protocol) {
+	/*
+	 * Undefined protocol, some guesswork needed.
+	 *
+	 * Old frontends which don't set the protocol use
+	 * one page directory only, thus pd[1] must be zero.
+	 * pd[1] of the 32bit struct layout and the lower
+	 * 32 bits of pd[0] of the 64bit struct layout have
+	 * the same location, so we can check that ...
+	 */
+	uint32_t *ptr32 = NULL;
+	uint32_t *ptr64 = NULL;
+#if defined(__i386__)
+	ptr32 = (void*)page->pd;
+	ptr64 = ((void*)page->pd) + 4;
+#elif defined(__x86_64__)
+	ptr32 = ((void*)page->pd) - 4;
+	ptr64 = (void*)page->pd;
+#endif
+	if (ptr32) {
+	    if (ptr32[1] == 0) {
+		mode = 32;
+		pd   = ptr32;
+	    } else {
+		mode = 64;
+		pd   = ptr64;
+	    }
+	}
+#if defined(__x86_64__)
+    } else if (strcmp(protocol, XEN_IO_PROTO_ABI_X86_32) == 0) {
+	/* 64bit dom0, 32bit domU */
+	mode = 32;
+	pd   = ((void*)page->pd) - 4;
+#elif defined(__i386__)
+    } else if (strcmp(protocol, XEN_IO_PROTO_ABI_X86_64) == 0) {
+	/* 32bit dom0, 64bit domU */
+	mode = 64;
+	pd   = ((void*)page->pd) + 4;
+#endif
+    }
+
+    if (xenfb->pixels) {
+        munmap(xenfb->pixels, xenfb->fbpages * XC_PAGE_SIZE);
+        xenfb->pixels = NULL;
+    }
+
+    xenfb->fbpages = (xenfb->fb_len + (XC_PAGE_SIZE - 1)) / XC_PAGE_SIZE;
+    n_fbdirs = xenfb->fbpages * mode / 8;
+    n_fbdirs = (n_fbdirs + (XC_PAGE_SIZE - 1)) / XC_PAGE_SIZE;
+
+    pgmfns = qemu_mallocz(sizeof(unsigned long) * n_fbdirs);
+    fbmfns = qemu_mallocz(sizeof(unsigned long) * xenfb->fbpages);
+
+    xenfb_copy_mfns(mode, n_fbdirs, pgmfns, pd);
+    map = xc_map_foreign_pages(xen_xc, xenfb->c.xendev.dom,
+			       PROT_READ, pgmfns, n_fbdirs);
+    if (map == NULL)
+	goto out;
+    xenfb_copy_mfns(mode, xenfb->fbpages, fbmfns, map);
+    munmap(map, n_fbdirs * XC_PAGE_SIZE);
+
+    xenfb->pixels = xc_map_foreign_pages(xen_xc, xenfb->c.xendev.dom,
+					 PROT_READ | PROT_WRITE, fbmfns, xenfb->fbpages);
+    if (xenfb->pixels == NULL)
+	goto out;
+
+    ret = 0; /* all is fine */
+
+out:
+    qemu_free(pgmfns);
+    qemu_free(fbmfns);
+    return ret;
+}
+
+static int xenfb_configure_fb(struct XenFB *xenfb, size_t fb_len_lim,
+			      int width, int height, int depth,
+			      size_t fb_len, int offset, int row_stride)
+{
+    size_t mfn_sz = sizeof(*((struct xenfb_page *)0)->pd);
+    size_t pd_len = sizeof(((struct xenfb_page *)0)->pd) / mfn_sz;
+    size_t fb_pages = pd_len * XC_PAGE_SIZE / mfn_sz;
+    size_t fb_len_max = fb_pages * XC_PAGE_SIZE;
+    int max_width, max_height;
+
+    if (fb_len_lim > fb_len_max) {
+	xen_be_printf(&xenfb->c.xendev, 0, "fb size limit %zu exceeds %zu, corrected\n",
+		      fb_len_lim, fb_len_max);
+	fb_len_lim = fb_len_max;
+    }
+    if (fb_len_lim && fb_len > fb_len_lim) {
+	xen_be_printf(&xenfb->c.xendev, 0, "frontend fb size %zu limited to %zu\n",
+		      fb_len, fb_len_lim);
+	fb_len = fb_len_lim;
+    }
+    if (depth != 8 && depth != 16 && depth != 24 && depth != 32) {
+	xen_be_printf(&xenfb->c.xendev, 0, "can't handle frontend fb depth %d\n",
+		      depth);
+	return -1;
+    }
+    if (row_stride <= 0 || row_stride > fb_len) {
+	xen_be_printf(&xenfb->c.xendev, 0, "invalid frontend stride %d\n", row_stride);
+	return -1;
+    }
+    max_width = row_stride / (depth / 8);
+    if (width < 0 || width > max_width) {
+	xen_be_printf(&xenfb->c.xendev, 0, "invalid frontend width %d limited to %d\n",
+		      width, max_width);
+	width = max_width;
+    }
+    if (offset < 0 || offset >= fb_len) {
+	xen_be_printf(&xenfb->c.xendev, 0, "invalid frontend offset %d (max %zu)\n",
+		      offset, fb_len - 1);
+	return -1;
+    }
+    max_height = (fb_len - offset) / row_stride;
+    if (height < 0 || height > max_height) {
+	xen_be_printf(&xenfb->c.xendev, 0, "invalid frontend height %d limited to %d\n",
+		      height, max_height);
+	height = max_height;
+    }
+    xenfb->fb_len = fb_len;
+    xenfb->row_stride = row_stride;
+    xenfb->depth = depth;
+    xenfb->width = width;
+    xenfb->height = height;
+    xenfb->offset = offset;
+    xenfb->up_fullscreen = 1;
+    xenfb->do_resize = 1;
+    xen_be_printf(&xenfb->c.xendev, 1, "framebuffer %dx%dx%d offset %d stride %d\n",
+		  width, height, depth, offset, row_stride);
+    return 0;
+}
+
+/* A convenient function for munging pixels between different depths */
+#define BLT(SRC_T,DST_T,RSB,GSB,BSB,RDB,GDB,BDB)                        \
+    for (line = y ; line < (y+h) ; line++) {				\
+	SRC_T *src = (SRC_T *)(xenfb->pixels				\
+			       + xenfb->offset				\
+			       + (line * xenfb->row_stride)		\
+			       + (x * xenfb->depth / 8));		\
+	DST_T *dst = (DST_T *)(data					\
+			       + (line * linesize)			\
+			       + (x * bpp / 8));			\
+	int col;							\
+	const int RSS = 32 - (RSB + GSB + BSB);				\
+	const int GSS = 32 - (GSB + BSB);				\
+	const int BSS = 32 - (BSB);					\
+	const uint32_t RSM = (~0U) << (32 - RSB);			\
+	const uint32_t GSM = (~0U) << (32 - GSB);			\
+	const uint32_t BSM = (~0U) << (32 - BSB);			\
+	const int RDS = 32 - (RDB + GDB + BDB);				\
+	const int GDS = 32 - (GDB + BDB);				\
+	const int BDS = 32 - (BDB);					\
+	const uint32_t RDM = (~0U) << (32 - RDB);			\
+	const uint32_t GDM = (~0U) << (32 - GDB);			\
+	const uint32_t BDM = (~0U) << (32 - BDB);			\
+	for (col = x ; col < (x+w) ; col++) {				\
+	    uint32_t spix = *src;					\
+	    *dst = (((spix << RSS) & RSM & RDM) >> RDS) |		\
+		(((spix << GSS) & GSM & GDM) >> GDS) |			\
+		(((spix << BSS) & BSM & BDM) >> BDS);			\
+	    src = (SRC_T *) ((unsigned long) src + xenfb->depth / 8);	\
+	    dst = (DST_T *) ((unsigned long) dst + bpp / 8);		\
+	}								\
+    }
+
+
+/*
+ * This copies data from the guest framebuffer region, into QEMU's
+ * displaysurface. qemu uses 16 or 32 bpp.  In case the pv framebuffer
+ * uses something else we must convert and copy, otherwise we can
+ * supply the buffer directly and no thing here.
+ */
+static void xenfb_guest_copy(struct XenFB *xenfb, int x, int y, int w, int h)
+{
+    int line, oops = 0;
+    int bpp = ds_get_bits_per_pixel(xenfb->c.ds);
+    int linesize = ds_get_linesize(xenfb->c.ds);
+    uint8_t *data = ds_get_data(xenfb->c.ds);
+
+    if (!is_buffer_shared(xenfb->c.ds->surface)) {
+        switch (xenfb->depth) {
+        case 8:
+            if (bpp == 16) {
+                BLT(uint8_t, uint16_t,   3, 3, 2,   5, 6, 5);
+            } else if (bpp == 32) {
+                BLT(uint8_t, uint32_t,   3, 3, 2,   8, 8, 8);
+            } else {
+                oops = 1;
+            }
+            break;
+        case 24:
+            if (bpp == 16) {
+                BLT(uint32_t, uint16_t,  8, 8, 8,   5, 6, 5);
+            } else if (bpp == 32) {
+                BLT(uint32_t, uint32_t,  8, 8, 8,   8, 8, 8);
+            } else {
+                oops = 1;
+            }
+            break;
+        default:
+            oops = 1;
+	}
+    }
+    if (oops) /* should not happen */
+        xen_be_printf(&xenfb->c.xendev, 0, "%s: oops: convert %d -> %d bpp?\n",
+                      __FUNCTION__, xenfb->depth, bpp);
+
+    dpy_update(xenfb->c.ds, x, y, w, h);
+}
+
+#ifdef XENFB_TYPE_REFRESH_PERIOD
+static int xenfb_queue_full(struct XenFB *xenfb)
+{
+    struct xenfb_page *page = xenfb->c.page;
+    uint32_t cons, prod;
+
+    if (!page)
+        return 1;
+
+    prod = page->in_prod;
+    cons = page->in_cons;
+    return prod - cons == XENFB_IN_RING_LEN;
+}
+
+static void xenfb_send_event(struct XenFB *xenfb, union xenfb_in_event *event)
+{
+    uint32_t prod;
+    struct xenfb_page *page = xenfb->c.page;
+
+    prod = page->in_prod;
+    /* caller ensures !xenfb_queue_full() */
+    xen_mb();                   /* ensure ring space available */
+    XENFB_IN_RING_REF(page, prod) = *event;
+    xen_wmb();                  /* ensure ring contents visible */
+    page->in_prod = prod + 1;
+
+    xen_be_send_notify(&xenfb->c.xendev);
+}
+
+static void xenfb_send_refresh_period(struct XenFB *xenfb, int period)
+{
+    union xenfb_in_event event;
+
+    memset(&event, 0, sizeof(event));
+    event.type = XENFB_TYPE_REFRESH_PERIOD;
+    event.refresh_period.period = period;
+    xenfb_send_event(xenfb, &event);
+}
+#endif
+
+/*
+ * Periodic update of display.
+ * Also transmit the refresh interval to the frontend.
+ *
+ * Never ever do any qemu display operations
+ * (resize, screen update) outside this function.
+ * Our screen might be inactive.  When asked for
+ * an update we know it is active.
+ */
+static void xenfb_update(void *opaque)
+{
+    struct XenFB *xenfb = opaque;
+    struct DisplayChangeListener *l;
+    int i;
+
+    if (xenfb->c.xendev.be_state != XenbusStateConnected)
+        return;
+
+    if (xenfb->feature_update) {
+#ifdef XENFB_TYPE_REFRESH_PERIOD
+        int period = 99999999;
+        int idle = 1;
+
+	if (xenfb_queue_full(xenfb))
+	    return;
+
+        for (l = xenfb->c.ds->listeners; l != NULL; l = l->next) {
+            if (l->idle)
+                continue;
+            idle = 0;
+            if (!l->gui_timer_interval) {
+                if (period > GUI_REFRESH_INTERVAL)
+                    period = GUI_REFRESH_INTERVAL;
+            } else {
+                if (period > l->gui_timer_interval)
+                    period = l->gui_timer_interval;
+            }
+        }
+        if (idle)
+	    period = XENFB_NO_REFRESH;
+
+	if (xenfb->refresh_period != period) {
+	    xenfb_send_refresh_period(xenfb, period);
+	    xenfb->refresh_period = period;
+            xen_be_printf(&xenfb->c.xendev, 1, "refresh period: %d\n", period);
+	}
+#else
+	; /* nothing */
+#endif
+    } else {
+	/* we don't get update notifications, thus use the
+	 * sledge hammer approach ... */
+	xenfb->up_fullscreen = 1;
+    }
+
+    /* resize if needed */
+    if (xenfb->do_resize) {
+        xenfb->do_resize = 0;
+        switch (xenfb->depth) {
+        case 16:
+        case 32:
+            /* console.c supported depth -> buffer can be used directly */
+            qemu_free_displaysurface(xenfb->c.ds);
+            xenfb->c.ds->surface = qemu_create_displaysurface_from
+                (xenfb->width, xenfb->height, xenfb->depth,
+                 xenfb->row_stride, xenfb->pixels + xenfb->offset);
+            break;
+        default:
+            /* we must convert stuff */
+            qemu_resize_displaysurface(xenfb->c.ds, xenfb->width, xenfb->height);
+            break;
+        }
+        xen_be_printf(&xenfb->c.xendev, 1, "update: resizing: %dx%d @ %d bpp%s\n",
+                      xenfb->width, xenfb->height, xenfb->depth,
+                      is_buffer_shared(xenfb->c.ds->surface) ? " (shared)" : "");
+        dpy_resize(xenfb->c.ds);
+        xenfb->up_fullscreen = 1;
+    }
+
+    /* run queued updates */
+    if (xenfb->up_fullscreen) {
+	xen_be_printf(&xenfb->c.xendev, 3, "update: fullscreen\n");
+	xenfb_guest_copy(xenfb, 0, 0, xenfb->width, xenfb->height);
+    } else if (xenfb->up_count) {
+	xen_be_printf(&xenfb->c.xendev, 3, "update: %d rects\n", xenfb->up_count);
+	for (i = 0; i < xenfb->up_count; i++)
+	    xenfb_guest_copy(xenfb,
+			     xenfb->up_rects[i].x,
+			     xenfb->up_rects[i].y,
+			     xenfb->up_rects[i].w,
+			     xenfb->up_rects[i].h);
+    } else {
+	xen_be_printf(&xenfb->c.xendev, 3, "update: nothing\n");
+    }
+    xenfb->up_count = 0;
+    xenfb->up_fullscreen = 0;
+}
+
+/* QEMU display state changed, so refresh the framebuffer copy */
+static void xenfb_invalidate(void *opaque)
+{
+    struct XenFB *xenfb = opaque;
+    xenfb->up_fullscreen = 1;
+}
+
+static void xenfb_handle_events(struct XenFB *xenfb)
+{
+    uint32_t prod, cons;
+    struct xenfb_page *page = xenfb->c.page;
+
+    prod = page->out_prod;
+    if (prod == page->out_cons)
+	return;
+    xen_rmb();		/* ensure we see ring contents up to prod */
+    for (cons = page->out_cons; cons != prod; cons++) {
+	union xenfb_out_event *event = &XENFB_OUT_RING_REF(page, cons);
+	int x, y, w, h;
+
+	switch (event->type) {
+	case XENFB_TYPE_UPDATE:
+	    if (xenfb->up_count == UP_QUEUE)
+		xenfb->up_fullscreen = 1;
+	    if (xenfb->up_fullscreen)
+		break;
+	    x = MAX(event->update.x, 0);
+	    y = MAX(event->update.y, 0);
+	    w = MIN(event->update.width, xenfb->width - x);
+	    h = MIN(event->update.height, xenfb->height - y);
+	    if (w < 0 || h < 0) {
+                xen_be_printf(&xenfb->c.xendev, 1, "bogus update ignored\n");
+		break;
+	    }
+	    if (x != event->update.x ||
+                y != event->update.y ||
+		w != event->update.width ||
+		h != event->update.height) {
+                xen_be_printf(&xenfb->c.xendev, 1, "bogus update clipped\n");
+	    }
+	    if (w == xenfb->width && h > xenfb->height / 2) {
+		/* scroll detector: updated more than 50% of the lines,
+		 * don't bother keeping track of the rectangles then */
+		xenfb->up_fullscreen = 1;
+	    } else {
+		xenfb->up_rects[xenfb->up_count].x = x;
+		xenfb->up_rects[xenfb->up_count].y = y;
+		xenfb->up_rects[xenfb->up_count].w = w;
+		xenfb->up_rects[xenfb->up_count].h = h;
+		xenfb->up_count++;
+	    }
+	    break;
+#ifdef XENFB_TYPE_RESIZE
+	case XENFB_TYPE_RESIZE:
+	    if (xenfb_configure_fb(xenfb, xenfb->fb_len,
+				   event->resize.width,
+				   event->resize.height,
+				   event->resize.depth,
+				   xenfb->fb_len,
+				   event->resize.offset,
+				   event->resize.stride) < 0)
+		break;
+	    xenfb_invalidate(xenfb);
+	    break;
+#endif
+	}
+    }
+    xen_mb();		/* ensure we're done with ring contents */
+    page->out_cons = cons;
+}
+
+static int fb_init(struct XenDevice *xendev)
+{
+    struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
+
+    fb->refresh_period = -1;
+
+#ifdef XENFB_TYPE_RESIZE
+    xenstore_write_be_int(xendev, "feature-resize", 1);
+#endif
+    return 0;
+}
+
+static int fb_connect(struct XenDevice *xendev)
+{
+    struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
+    struct xenfb_page *fb_page;
+    int videoram;
+    int rc;
+
+    if (xenstore_read_fe_int(xendev, "videoram", &videoram) == -1)
+	videoram = 0;
+
+    rc = common_bind(&fb->c);
+    if (rc != 0)
+	return rc;
+
+    fb_page = fb->c.page;
+    rc = xenfb_configure_fb(fb, videoram * 1024 * 1024U,
+			    fb_page->width, fb_page->height, fb_page->depth,
+			    fb_page->mem_length, 0, fb_page->line_length);
+    if (rc != 0)
+	return rc;
+
+    rc = xenfb_map_fb(fb);
+    if (rc != 0)
+	return rc;
+
+#if 0  /* handled in xen_init_display() for now */
+    if (!fb->have_console) {
+        fb->c.ds = graphic_console_init(xenfb_update,
+                                        xenfb_invalidate,
+                                        NULL,
+                                        NULL,
+                                        fb);
+        fb->have_console = 1;
+    }
+#endif
+
+    if (xenstore_read_fe_int(xendev, "feature-update", &fb->feature_update) == -1)
+	fb->feature_update = 0;
+    if (fb->feature_update)
+	xenstore_write_be_int(xendev, "request-update", 1);
+
+    xen_be_printf(xendev, 1, "feature-update=%d, videoram=%d\n",
+		  fb->feature_update, videoram);
+    return 0;
+}
+
+static void fb_disconnect(struct XenDevice *xendev)
+{
+    struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
+
+    /*
+     * FIXME: qemu can't un-init gfx display (yet?).
+     *   Replacing the framebuffer with anonymous shared memory
+     *   instead.  This releases the guest pages and keeps qemu happy.
+     */
+    fb->pixels = mmap(fb->pixels, fb->fbpages * XC_PAGE_SIZE,
+                      PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON,
+                      -1, 0);
+    common_unbind(&fb->c);
+    fb->feature_update = 0;
+    fb->bug_trigger    = 0;
+}
+
+static void fb_frontend_changed(struct XenDevice *xendev, const char *node)
+{
+    struct XenFB *fb = container_of(xendev, struct XenFB, c.xendev);
+
+    /*
+     * Set state to Connected *again* once the frontend switched
+     * to connected.  We must trigger the watch a second time to
+     * workaround a frontend bug.
+     */
+    if (fb->bug_trigger == 0 && strcmp(node, "state") == 0 &&
+        xendev->fe_state == XenbusStateConnected &&
+        xendev->be_state == XenbusStateConnected) {
+        xen_be_printf(xendev, 2, "re-trigger connected (frontend bug)\n");
+        xen_be_set_state(xendev, XenbusStateConnected);
+        fb->bug_trigger = 1; /* only once */
+    }
+}
+
+static void fb_event(struct XenDevice *xendev)
+{
+    struct XenFB *xenfb = container_of(xendev, struct XenFB, c.xendev);
+
+    xenfb_handle_events(xenfb);
+    xen_be_send_notify(&xenfb->c.xendev);
+}
+
+/* -------------------------------------------------------------------- */
+
+struct XenDevOps xen_kbdmouse_ops = {
+    .size       = sizeof(struct XenInput),
+    .init       = input_init,
+    .connect    = input_connect,
+    .disconnect = input_disconnect,
+    .event      = input_event,
+};
+
+struct XenDevOps xen_framebuffer_ops = {
+    .size       = sizeof(struct XenFB),
+    .init       = fb_init,
+    .connect    = fb_connect,
+    .disconnect = fb_disconnect,
+    .event      = fb_event,
+    .frontend_changed = fb_frontend_changed,
+};
+
+/*
+ * FIXME/TODO: Kill this.
+ * Temporary needed while DisplayState reorganization is in flight.
+ */
+void xen_init_display(int domid)
+{
+    struct XenDevice *xfb, *xin;
+    struct XenFB *fb;
+    struct XenInput *in;
+    int i = 0;
+
+wait_more:
+    i++;
+    main_loop_wait(10); /* miliseconds */
+    xfb = xen_be_find_xendev("vfb", domid, 0);
+    xin = xen_be_find_xendev("vkbd", domid, 0);
+    if (!xfb || !xin) {
+        if (i < 256)
+            goto wait_more;
+        xen_be_printf(NULL, 1, "displaystate setup failed\n");
+        return;
+    }
+
+    /* vfb */
+    fb = container_of(xfb, struct XenFB, c.xendev);
+    fb->c.ds = graphic_console_init(xenfb_update,
+                                    xenfb_invalidate,
+                                    NULL,
+                                    NULL,
+                                    fb);
+    fb->have_console = 1;
+
+    /* vkbd */
+    in = container_of(xin, struct XenInput, c.xendev);
+    in->c.ds = fb->c.ds;
+
+    /* retry ->init() */
+    xen_be_check_state(xin);
+    xen_be_check_state(xfb);
+}