Re: [PATCH 2/2] xen pvfb: Para-virtual framebuffer, keyboard andpointer driver

[Jeremy Fitzhardinge]

Markus Armbruster wrote:
> This is a pair of Xen para-virtual frontend device drivers:
> drivers/video/xen-fbfront.c provides a framebuffer, and
> drivers/input/xen-kbdfront provides keyboard and mouse.
>   

Unless they're actually inter-dependent, could you post this as two 
separate patches?  I don't know anything about these parts of the 
kernel, so it would be nice to make it very obvious which changes are fb 
vs mouse/keyboard.

(I guess input/* vs video/* should make it obvious, but it looks like 
input has a config dependency on fb, so I'll avoid making too many 
presumptions...)

(Couple of comments below)

   J

> The backends run in dom0 user space.
>
> Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx>
>
> ---
>
>  drivers/input/Kconfig            |    9 
>  drivers/input/Makefile           |    2 
>  drivers/input/xen-kbdfront.c     |  337 +++++++++++++++++++++++
>  drivers/video/Kconfig            |   14 
>  drivers/video/Makefile           |    1 
>  drivers/video/xen-fbfront.c      |  550 +++++++++++++++++++++++++++++++++++++++
>  include/xen/interface/io/fbif.h  |  124 ++++++++
>  include/xen/interface/io/kbdif.h |  114 ++++++++
>  8 files changed, 1151 insertions(+)
>
> diff --git a/drivers/input/Kconfig b/drivers/input/Kconfig
> index 9dea14d..5f9d860 100644
> --- a/drivers/input/Kconfig
> +++ b/drivers/input/Kconfig
> @@ -149,6 +149,15 @@ config INPUT_APMPOWER
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called apm-power.
>  
> +config XEN_KBDDEV_FRONTEND
> +	tristate "Xen virtual keyboard and mouse support"
> +	depends on XEN_FBDEV_FRONTEND
> +	default y
> +	help
> +	  This driver implements the front-end of the Xen virtual
> +	  keyboard and mouse device driver.  It communicates with a back-end
> +	  in another domain.
> +
>  comment "Input Device Drivers"
>  
>  source "drivers/input/keyboard/Kconfig"
> diff --git a/drivers/input/Makefile b/drivers/input/Makefile
> index 2ae87b1..98c4f9a 100644
> --- a/drivers/input/Makefile
> +++ b/drivers/input/Makefile
> @@ -23,3 +23,5 @@ obj-$(CONFIG_INPUT_TOUCHSCREEN)	+= touchscreen/
>  obj-$(CONFIG_INPUT_MISC)	+= misc/
>  
>  obj-$(CONFIG_INPUT_APMPOWER)	+= apm-power.o
> +
> +obj-$(CONFIG_XEN_KBDDEV_FRONTEND)	+= xen-kbdfront.o
> diff --git a/drivers/input/xen-kbdfront.c b/drivers/input/xen-kbdfront.c
> new file mode 100644
> index 0000000..84f65cf
> --- /dev/null
> +++ b/drivers/input/xen-kbdfront.c
> @@ -0,0 +1,337 @@
> +/*
> + * Xen para-virtual input device
> + *
> + * Copyright (C) 2005 Anthony Liguori <aliguori@xxxxxxxxxx>
> + * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@xxxxxxxxxx>
> + *
> + *  Based on linux/drivers/input/mouse/sermouse.c
> + *
> + *  This file is subject to the terms and conditions of the GNU General Public
> + *  License. See the file COPYING in the main directory of this archive for
> + *  more details.
> + */
> +
> +/*
> + * TODO:
> + *
> + * Switch to grant tables together with xen-fbfront.c.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/module.h>
> +#include <linux/input.h>
> +#include <asm/xen/hypervisor.h>
> +#include <xen/events.h>
> +#include <xen/page.h>
> +#include <xen/interface/io/fbif.h>
> +#include <xen/interface/io/kbdif.h>
> +#include <xen/xenbus.h>
> +
> +struct xenkbd_info {
> +	struct input_dev *kbd;
> +	struct input_dev *ptr;
> +	struct xenkbd_page *page;
> +	int evtchn, irq;
> +	struct xenbus_device *xbdev;
> +	char phys[32];
> +};
> +
> +static int xenkbd_remove(struct xenbus_device *);
> +static int xenkbd_connect_backend(struct xenbus_device *, struct xenkbd_info *);
> +static void xenkbd_disconnect_backend(struct xenkbd_info *);
> +
> +/*
> + * Note: if you need to send out events, see xenfb_do_update() for how
> + * to do that.
> + */
> +
> +static irqreturn_t input_handler(int rq, void *dev_id)
> +{
> +	struct xenkbd_info *info = dev_id;
> +	struct xenkbd_page *page = info->page;
> +	__u32 cons, prod;
> +
> +	prod = page->in_prod;
> +	if (prod == page->in_cons)
> +		return IRQ_HANDLED;
> +	rmb();			/* ensure we see ring contents up to prod */
> +	for (cons = page->in_cons; cons != prod; cons++) {
> +		union xenkbd_in_event *event;
> +		struct input_dev *dev;
> +		event = &XENKBD_IN_RING_REF(page, cons);
> +
> +		dev = info->ptr;
> +		switch (event->type) {
> +		case XENKBD_TYPE_MOTION:
> +			input_report_rel(dev, REL_X, event->motion.rel_x);
> +			input_report_rel(dev, REL_Y, event->motion.rel_y);
> +			break;
> +		case XENKBD_TYPE_KEY:
> +			dev = NULL;
> +			if (test_bit(event->key.keycode, info->kbd->keybit))
> +				dev = info->kbd;
> +			if (test_bit(event->key.keycode, info->ptr->keybit))
> +				dev = info->ptr;
> +			if (dev)
> +				input_report_key(dev, event->key.keycode,
> +						 event->key.pressed);
> +			else
> +				printk(KERN_WARNING
> +				       "xenkbd: unhandled keycode 0x%x\n",
> +				       event->key.keycode);
> +			break;
> +		case XENKBD_TYPE_POS:
> +			input_report_abs(dev, ABS_X, event->pos.abs_x);
> +			input_report_abs(dev, ABS_Y, event->pos.abs_y);
> +			break;
> +		}
> +		if (dev)
> +			input_sync(dev);
> +	}
> +	mb();			/* ensure we got ring contents */
> +	page->in_cons = cons;
> +	notify_remote_via_irq(info->irq);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int __devinit xenkbd_probe(struct xenbus_device *dev,
> +				  const struct xenbus_device_id *id)
> +{
> +	int ret, i;
> +	struct xenkbd_info *info;
> +	struct input_dev *kbd, *ptr;
> +
> +	info = kzalloc(sizeof(*info), GFP_KERNEL);
> +	if (!info) {
> +		xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
> +		return -ENOMEM;
> +	}
> +	dev->dev.driver_data = info;
> +	info->xbdev = dev;
> +	snprintf(info->phys, sizeof(info->phys), "xenbus/%s", dev->nodename);
> +
> +	info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
> +	if (!info->page)
> +		goto error_nomem;
> +
> +	/* keyboard */
> +	kbd = input_allocate_device();
> +	if (!kbd)
> +		goto error_nomem;
> +	kbd->name = "Xen Virtual Keyboard";
> +	kbd->phys = info->phys;
> +	kbd->id.bustype = BUS_PCI;
> +	kbd->id.vendor = 0x5853;
> +	kbd->id.product = 0xffff;
> +	kbd->evbit[0] = BIT(EV_KEY);
> +	for (i = KEY_ESC; i < KEY_UNKNOWN; i++)
> +		set_bit(i, kbd->keybit);
> +	for (i = KEY_OK; i < KEY_MAX; i++)
> +		set_bit(i, kbd->keybit);
> +
> +	ret = input_register_device(kbd);
> +	if (ret) {
> +		input_free_device(kbd);
> +		xenbus_dev_fatal(dev, ret, "input_register_device(kbd)");
> +		goto error;
> +	}
> +	info->kbd = kbd;
> +
> +	/* pointing device */
> +	ptr = input_allocate_device();
> +	if (!ptr)
> +		goto error_nomem;
> +	ptr->name = "Xen Virtual Pointer";
> +	ptr->phys = info->phys;
> +	ptr->id.bustype = BUS_PCI;
> +	ptr->id.vendor = 0x5853;
> +	ptr->id.product = 0xfffe;
> +	ptr->evbit[0] = BIT(EV_KEY) | BIT(EV_REL) | BIT(EV_ABS);
> +	for (i = BTN_LEFT; i <= BTN_TASK; i++)
> +		set_bit(i, ptr->keybit);
> +	ptr->relbit[0] = BIT(REL_X) | BIT(REL_Y);
> +	input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
> +	input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
> +
> +	ret = input_register_device(ptr);
> +	if (ret) {
> +		input_free_device(ptr);
> +		xenbus_dev_fatal(dev, ret, "input_register_device(ptr)");
> +		goto error;
> +	}
> +	info->ptr = ptr;
> +
> +	ret = xenkbd_connect_backend(dev, info);
> +	if (ret < 0)
> +		goto error;
> +
> +	return 0;
> +
> + error_nomem:
> +	ret = -ENOMEM;
> +	xenbus_dev_fatal(dev, ret, "allocating device memory");
> + error:
> +	xenkbd_remove(dev);
>   

This is happy if dev->info is only partially initialized?

> +	return ret;
> +}
> +
> +static int xenkbd_resume(struct xenbus_device *dev)
> +{
> +	struct xenkbd_info *info = dev->dev.driver_data;
> +
> +	xenkbd_disconnect_backend(info);
> +	memset(info->page, 0, PAGE_SIZE);
> +	return xenkbd_connect_backend(dev, info);
> +}
> +
> +static int xenkbd_remove(struct xenbus_device *dev)
> +{
> +	struct xenkbd_info *info = dev->dev.driver_data;
> +
> +	xenkbd_disconnect_backend(info);
> +	input_unregister_device(info->kbd);
> +	input_unregister_device(info->ptr);
>   

Does this free kdb and ptr?

> +	free_page((unsigned long)info->page);
> +	kfree(info);
> +	return 0;
> +}
> +
> +static int xenkbd_connect_backend(struct xenbus_device *dev,
> +				  struct xenkbd_info *info)
> +{
> +	int ret;
> +	struct xenbus_transaction xbt;
> +
> +	ret = xenbus_alloc_evtchn(dev, &info->evtchn);
> +	if (ret)
> +		return ret;
> +	ret = bind_evtchn_to_irqhandler(info->evtchn, input_handler,
> +					0, dev->devicetype, info);
> +	if (ret < 0) {
> +		xenbus_free_evtchn(dev, info->evtchn);
> +		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
> +		return ret;
> +	}
> +	info->irq = ret;
> +
> + again:
> +	ret = xenbus_transaction_start(&xbt);
> +	if (ret) {
> +		xenbus_dev_fatal(dev, ret, "starting transaction");
> +		return ret;
> +	}
> +	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
> +			    virt_to_mfn(info->page));
> +	if (ret)
> +		goto error_xenbus;
> +	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
> +			    info->evtchn);
> +	if (ret)
> +		goto error_xenbus;
> +	ret = xenbus_transaction_end(xbt, 0);
> +	if (ret) {
> +		if (ret == -EAGAIN)
> +			goto again;
> +		xenbus_dev_fatal(dev, ret, "completing transaction");
> +		return ret;
> +	}
> +
> +	xenbus_switch_state(dev, XenbusStateInitialised);
> +	return 0;
> +
> + error_xenbus:
> +	xenbus_transaction_end(xbt, 1);
> +	xenbus_dev_fatal(dev, ret, "writing xenstore");
> +	return ret;
> +}
> +
> +static void xenkbd_disconnect_backend(struct xenkbd_info *info)
> +{
> +	if (info->irq >= 0)
> +		unbind_from_irqhandler(info->irq, info);
> +	info->evtchn = info->irq = -1;
> +}
> +
> +static void xenkbd_backend_changed(struct xenbus_device *dev,
> +				   enum xenbus_state backend_state)
> +{
> +	struct xenkbd_info *info = dev->dev.driver_data;
> +	int ret, val;
> +
> +	switch (backend_state) {
> +	case XenbusStateInitialising:
> +	case XenbusStateInitialised:
> +	case XenbusStateUnknown:
> +	case XenbusStateClosed:
> +		break;
> +
> +	case XenbusStateInitWait:
> +InitWait:
> +		ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
> +				   "feature-abs-pointer", "%d", &val);
> +		if (ret < 0)
> +			val = 0;
> +		if (val) {
> +			ret = xenbus_printf(XBT_NIL, info->xbdev->nodename,
> +					    "request-abs-pointer", "1");
> +			if (ret)
> +				printk(KERN_WARNING
> +				       "xenkbd: can't request abs-pointer");
> +		}
> +		xenbus_switch_state(dev, XenbusStateConnected);
> +		break;
> +
> +	case XenbusStateConnected:
> +		/*
> +		 * Work around xenbus race condition: If backend goes
> +		 * through InitWait to Connected fast enough, we can
> +		 * get Connected twice here.
> +		 */
> +		if (dev->state != XenbusStateConnected)
> +			goto InitWait; /* no InitWait seen yet, fudge it */
> +		break;
> +
> +	case XenbusStateClosing:
> +		xenbus_frontend_closed(dev);
> +		break;
> +	}
> +}
> +
> +static struct xenbus_device_id xenkbd_ids[] = {
> +	{ "vkbd" },
> +	{ "" }
> +};
> +
> +static struct xenbus_driver xenkbd = {
> +	.name = "vkbd",
> +	.owner = THIS_MODULE,
> +	.ids = xenkbd_ids,
> +	.probe = xenkbd_probe,
> +	.remove = xenkbd_remove,
> +	.resume = xenkbd_resume,
> +	.otherend_changed = xenkbd_backend_changed,
> +};
> +
> +static int __init xenkbd_init(void)
> +{
> +	if (!is_running_on_xen())
> +		return -ENODEV;
> +
> +	/* Nothing to do if running in dom0. */
> +	if (is_initial_xendomain())
> +		return -ENODEV;
> +
> +	return xenbus_register_frontend(&xenkbd);
> +}
> +
> +static void __exit xenkbd_cleanup(void)
> +{
> +	xenbus_unregister_driver(&xenkbd);
> +}
> +
> +module_init(xenkbd_init);
> +module_exit(xenkbd_cleanup);
> +
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index 758435f..67de177 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -1903,6 +1903,20 @@ config FB_VIRTUAL
>  
>  	  If unsure, say N.
>  
> +config XEN_FBDEV_FRONTEND
> +	tristate "Xen virtual frame buffer support"
> +	depends on FB && XEN
> +	select FB_SYS_FILLRECT
> +	select FB_SYS_COPYAREA
> +	select FB_SYS_IMAGEBLIT
> +	select FB_SYS_FOPS
> +	select FB_DEFERRED_IO
> +	default y
> +	help
> +	  This driver implements the front-end of the Xen virtual
> +	  frame buffer driver.  It communicates with a back-end
> +	  in another domain.
> +
>  source "drivers/video/omap/Kconfig"
>  
>  source "drivers/video/backlight/Kconfig"
> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
> index 83e02b3..d3ab9b2 100644
> --- a/drivers/video/Makefile
> +++ b/drivers/video/Makefile
> @@ -113,6 +113,7 @@ obj-$(CONFIG_FB_PS3)		  += ps3fb.o
>  obj-$(CONFIG_FB_SM501)            += sm501fb.o
>  obj-$(CONFIG_FB_XILINX)           += xilinxfb.o
>  obj-$(CONFIG_FB_OMAP)             += omap/
> +obj-$(CONFIG_XEN_FBDEV_FRONTEND)  += xen-fbfront.o
>  
>  # Platform or fallback drivers go here
>  obj-$(CONFIG_FB_UVESA)            += uvesafb.o
> diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c
> new file mode 100644
> index 0000000..bf8f900
> --- /dev/null
> +++ b/drivers/video/xen-fbfront.c
> @@ -0,0 +1,550 @@
> +/*
> + * Xen para-virtual frame buffer device
> + *
> + * Copyright (C) 2005-2006 Anthony Liguori <aliguori@xxxxxxxxxx>
> + * Copyright (C) 2006-2008 Red Hat, Inc., Markus Armbruster <armbru@xxxxxxxxxx>
> + *
> + *  Based on linux/drivers/video/q40fb.c
> + *
> + *  This file is subject to the terms and conditions of the GNU General Public
> + *  License. See the file COPYING in the main directory of this archive for
> + *  more details.
> + */
> +
> +/*
> + * TODO:
> + *
> + * Switch to grant tables when they become capable of dealing with the
> + * frame buffer.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/fb.h>
> +#include <linux/module.h>
> +#include <linux/vmalloc.h>
> +#include <linux/mm.h>
> +#include <asm/xen/hypervisor.h>
> +#include <xen/events.h>
> +#include <xen/page.h>
> +#include <xen/interface/io/fbif.h>
> +#include <xen/interface/io/protocols.h>
> +#include <xen/xenbus.h>
> +
> +struct xenfb_info {
> +	unsigned char		*fb;
> +	struct fb_info		*fb_info;
> +	int			x1, y1, x2, y2;	/* dirty rectangle,
> +						   protected by dirty_lock */
> +	spinlock_t		dirty_lock;
> +	int			nr_pages;
> +	int			evtchn, irq;
> +	struct xenfb_page	*page;
> +	unsigned long 		*mfns;
> +	int			update_wanted; /* XENFB_TYPE_UPDATE wanted */
> +
> +	struct xenbus_device	*xbdev;
> +};
> +
> +static u32 xenfb_mem_len = XENFB_WIDTH * XENFB_HEIGHT * XENFB_DEPTH / 8;
> +
> +static int xenfb_remove(struct xenbus_device *);
> +static void xenfb_init_shared_page(struct xenfb_info *);
> +static int xenfb_connect_backend(struct xenbus_device *, struct xenfb_info *);
> +static void xenfb_disconnect_backend(struct xenfb_info *);
> +
> +static void xenfb_do_update(struct xenfb_info *info,
> +			    int x, int y, int w, int h)
> +{
> +	union xenfb_out_event event;
> +	u32 prod;
> +
> +	event.type = XENFB_TYPE_UPDATE;
> +	event.update.x = x;
> +	event.update.y = y;
> +	event.update.width = w;
> +	event.update.height = h;
> +
> +	prod = info->page->out_prod;
> +	/* caller ensures !xenfb_queue_full() */
> +	mb();			/* ensure ring space available */
> +	XENFB_OUT_RING_REF(info->page, prod) = event;
> +	wmb();			/* ensure ring contents visible */
> +	info->page->out_prod = prod + 1;
> +
> +	notify_remote_via_irq(info->irq);
> +}
> +
> +static int xenfb_queue_full(struct xenfb_info *info)
> +{
> +	u32 cons, prod;
> +
> +	prod = info->page->out_prod;
> +	cons = info->page->out_cons;
> +	return prod - cons == XENFB_OUT_RING_LEN;
> +}
> +
> +static void xenfb_refresh(struct xenfb_info *info,
> +			  int x1, int y1, int w, int h)
> +{
> +	unsigned long flags;
> +	int y2 = y1 + h - 1;
> +	int x2 = x1 + w - 1;
> +
> +	if (!info->update_wanted)
> +		return;
> +
> +	spin_lock_irqsave(&info->dirty_lock, flags);
> +
> +	/* Combine with dirty rectangle: */
> +	if (info->y1 < y1)
> +		y1 = info->y1;
> +	if (info->y2 > y2)
> +		y2 = info->y2;
> +	if (info->x1 < x1)
> +		x1 = info->x1;
> +	if (info->x2 > x2)
> +		x2 = info->x2;
> +
> +	if (xenfb_queue_full(info)) {
> +		/* Can't send right now, stash it in the dirty rectangle */
> +		info->x1 = x1;
> +		info->x2 = x2;
> +		info->y1 = y1;
> +		info->y2 = y2;
> +		spin_unlock_irqrestore(&info->dirty_lock, flags);
> +		return;
> +	}
> +
> +	/* Clear dirty rectangle: */
> +	info->x1 = info->y1 = INT_MAX;
> +	info->x2 = info->y2 = 0;
> +
> +	spin_unlock_irqrestore(&info->dirty_lock, flags);
> +
> +	if (x1 <= x2 && y1 <= y2)
> +		xenfb_do_update(info, x1, y1, x2 - x1 + 1, y2 - y1 + 1);
> +}
> +
> +static void xenfb_deferred_io(struct fb_info *fb_info,
> +			      struct list_head *pagelist)
> +{
> +	struct xenfb_info *info = fb_info->par;
> +	struct page *page;
> +	unsigned long beg, end;
> +	int y1, y2, miny, maxy;
> +
> +	miny = INT_MAX;
> +	maxy = 0;
> +	list_for_each_entry(page, pagelist, lru) {
> +		beg = page->index << PAGE_SHIFT;
> +		end = beg + PAGE_SIZE - 1;
> +		y1 = beg / fb_info->fix.line_length;
> +		y2 = end / fb_info->fix.line_length;
> +		if (y2 >= fb_info->var.yres)
> +			y2 = fb_info->var.yres - 1;
> +		if (miny > y1)
> +			miny = y1;
> +		if (maxy < y2)
> +			maxy = y2;
> +	}
> +	xenfb_refresh(info, 0, miny, fb_info->var.xres, maxy - miny + 1);
> +}
> +
> +static struct fb_deferred_io xenfb_defio = {
> +	.delay		= HZ / 20,
> +	.deferred_io	= xenfb_deferred_io,
> +};
> +
> +static int xenfb_setcolreg(unsigned regno, unsigned red, unsigned green,
> +			   unsigned blue, unsigned transp,
> +			   struct fb_info *info)
> +{
> +	u32 v;
> +
> +	if (regno > info->cmap.len)
> +		return 1;
> +
> +#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
> +	red = CNVT_TOHW(red, info->var.red.length);
> +	green = CNVT_TOHW(green, info->var.green.length);
> +	blue = CNVT_TOHW(blue, info->var.blue.length);
> +	transp = CNVT_TOHW(transp, info->var.transp.length);
> +#undef CNVT_TOHW
> +
> +	v = (red << info->var.red.offset) |
> +	    (green << info->var.green.offset) |
> +	    (blue << info->var.blue.offset);
> +
> +	switch (info->var.bits_per_pixel) {
> +	case 16:
> +	case 24:
> +	case 32:
> +		((u32 *)info->pseudo_palette)[regno] = v;
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static void xenfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
> +{
> +	struct xenfb_info *info = p->par;
> +
> +	sys_fillrect(p, rect);
> +	xenfb_refresh(info, rect->dx, rect->dy, rect->width, rect->height);
> +}
> +
> +static void xenfb_imageblit(struct fb_info *p, const struct fb_image *image)
> +{
> +	struct xenfb_info *info = p->par;
> +
> +	sys_imageblit(p, image);
> +	xenfb_refresh(info, image->dx, image->dy, image->width, image->height);
> +}
> +
> +static void xenfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
> +{
> +	struct xenfb_info *info = p->par;
> +
> +	sys_copyarea(p, area);
> +	xenfb_refresh(info, area->dx, area->dy, area->width, area->height);
> +}
> +
> +static ssize_t xenfb_write(struct fb_info *p, const char __user *buf,
> +			size_t count, loff_t *ppos)
> +{
> +	struct xenfb_info *info = p->par;
> +	ssize_t res;
> +
> +	res = fb_sys_write(p, buf, count, ppos);
> +	xenfb_refresh(info, 0, 0, info->page->width, info->page->height);
> +	return res;
> +}
> +
> +static struct fb_ops xenfb_fb_ops = {
> +	.owner		= THIS_MODULE,
> +	.fb_read	= fb_sys_read,
> +	.fb_write	= xenfb_write,
> +	.fb_setcolreg	= xenfb_setcolreg,
> +	.fb_fillrect	= xenfb_fillrect,
> +	.fb_copyarea	= xenfb_copyarea,
> +	.fb_imageblit	= xenfb_imageblit,
> +};
> +
> +static irqreturn_t xenfb_event_handler(int rq, void *dev_id)
> +{
> +	/*
> +	 * No in events recognized, simply ignore them all.
> +	 * If you need to recognize some, see xen-kbdfront's
> +	 * input_handler() for how to do that.
> +	 */
> +	struct xenfb_info *info = dev_id;
> +	struct xenfb_page *page = info->page;
> +
> +	if (page->in_cons != page->in_prod) {
> +		info->page->in_cons = info->page->in_prod;
> +		notify_remote_via_irq(info->irq);
> +	}
> +
> +	/* Flush dirty rectangle: */
> +	xenfb_refresh(info, INT_MAX, INT_MAX, -INT_MAX, -INT_MAX);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int __devinit xenfb_probe(struct xenbus_device *dev,
> +				 const struct xenbus_device_id *id)
> +{
> +	struct xenfb_info *info;
> +	struct fb_info *fb_info;
> +	int ret;
> +
> +	info = kzalloc(sizeof(*info), GFP_KERNEL);
> +	if (info == NULL) {
> +		xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
> +		return -ENOMEM;
> +	}
> +	dev->dev.driver_data = info;
> +	info->xbdev = dev;
> +	info->irq = -1;
> +	info->x1 = info->y1 = INT_MAX;
> +	spin_lock_init(&info->dirty_lock);
> +
> +	info->fb = vmalloc(xenfb_mem_len);
> +	if (info->fb == NULL)
> +		goto error_nomem;
> +	memset(info->fb, 0, xenfb_mem_len);
> +
> +	info->nr_pages = (xenfb_mem_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> +
> +	info->mfns = vmalloc(sizeof(unsigned long) * info->nr_pages);
> +	if (!info->mfns)
> +		goto error_nomem;
> +
> +	/* set up shared page */
> +	info->page = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
> +	if (!info->page)
> +		goto error_nomem;
> +
> +	xenfb_init_shared_page(info);
> +
> +	/* abusing framebuffer_alloc() to allocate pseudo_palette */
> +	fb_info = framebuffer_alloc(sizeof(u32) * 256, NULL);
> +	if (fb_info == NULL)
> +		goto error_nomem;
> +
> +	/* complete the abuse: */
> +	fb_info->pseudo_palette = fb_info->par;
> +	fb_info->par = info;
> +
> +	fb_info->screen_base = info->fb;
> +
> +	fb_info->fbops = &xenfb_fb_ops;
> +	fb_info->var.xres_virtual = fb_info->var.xres = info->page->width;
> +	fb_info->var.yres_virtual = fb_info->var.yres = info->page->height;
> +	fb_info->var.bits_per_pixel = info->page->depth;
> +
> +	fb_info->var.red = (struct fb_bitfield){16, 8, 0};
> +	fb_info->var.green = (struct fb_bitfield){8, 8, 0};
> +	fb_info->var.blue = (struct fb_bitfield){0, 8, 0};
> +
> +	fb_info->var.activate = FB_ACTIVATE_NOW;
> +	fb_info->var.height = -1;
> +	fb_info->var.width = -1;
> +	fb_info->var.vmode = FB_VMODE_NONINTERLACED;
> +
> +	fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
> +	fb_info->fix.line_length = info->page->line_length;
> +	fb_info->fix.smem_start = 0;
> +	fb_info->fix.smem_len = xenfb_mem_len;
> +	strcpy(fb_info->fix.id, "xen");
> +	fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
> +	fb_info->fix.accel = FB_ACCEL_NONE;
> +
> +	fb_info->flags = FBINFO_FLAG_DEFAULT;
> +
> +	ret = fb_alloc_cmap(&fb_info->cmap, 256, 0);
> +	if (ret < 0) {
> +		framebuffer_release(fb_info);
> +		xenbus_dev_fatal(dev, ret, "fb_alloc_cmap");
> +		goto error;
> +	}
> +
> +	fb_info->fbdefio = &xenfb_defio;
> +	fb_deferred_io_init(fb_info);
> +
> +	ret = register_framebuffer(fb_info);
> +	if (ret) {
> +		fb_dealloc_cmap(&fb_info->cmap);
> +		fb_deferred_io_cleanup(fb_info);
> +		framebuffer_release(fb_info);
> +		xenbus_dev_fatal(dev, ret, "register_framebuffer");
> +		goto error;
> +	}
> +	info->fb_info = fb_info;
> +
> +	ret = xenfb_connect_backend(dev, info);
> +	if (ret < 0)
> +		goto error;
> +
> +	return 0;
> +
> + error_nomem:
> +	ret = -ENOMEM;
> +	xenbus_dev_fatal(dev, ret, "allocating device memory");
> + error:
> +	xenfb_remove(dev);
> +	return ret;
> +}
> +
> +static int xenfb_resume(struct xenbus_device *dev)
> +{
> +	struct xenfb_info *info = dev->dev.driver_data;
> +
> +	xenfb_disconnect_backend(info);
> +	xenfb_init_shared_page(info);
> +	return xenfb_connect_backend(dev, info);
> +}
> +
> +static int xenfb_remove(struct xenbus_device *dev)
> +{
> +	struct xenfb_info *info = dev->dev.driver_data;
> +
> +	xenfb_disconnect_backend(info);
> +	if (info->fb_info) {
> +		fb_deferred_io_cleanup(info->fb_info);
> +		unregister_framebuffer(info->fb_info);
> +		fb_dealloc_cmap(&info->fb_info->cmap);
> +		framebuffer_release(info->fb_info);
> +	}
> +	free_page((unsigned long)info->page);
> +	vfree(info->mfns);
> +	vfree(info->fb);
> +	kfree(info);
> +
> +	return 0;
> +}
> +
> +static unsigned long vmalloc_to_mfn(void *address)
> +{
> +	return pfn_to_mfn(vmalloc_to_pfn(address));
> +}
> +
> +static void xenfb_init_shared_page(struct xenfb_info *info)
> +{
> +	int i;
> +
> +	for (i = 0; i < info->nr_pages; i++)
> +		info->mfns[i] = vmalloc_to_mfn(info->fb + i * PAGE_SIZE);
> +
> +	info->page->pd[0] = vmalloc_to_mfn(info->mfns);
> +	info->page->pd[1] = 0;
> +	info->page->width = XENFB_WIDTH;
> +	info->page->height = XENFB_HEIGHT;
> +	info->page->depth = XENFB_DEPTH;
> +	info->page->line_length = (info->page->depth / 8) * info->page->width;
> +	info->page->mem_length = xenfb_mem_len;
> +	info->page->in_cons = info->page->in_prod = 0;
> +	info->page->out_cons = info->page->out_prod = 0;
> +}
> +
> +static int xenfb_connect_backend(struct xenbus_device *dev,
> +				 struct xenfb_info *info)
> +{
> +	int ret;
> +	struct xenbus_transaction xbt;
> +
> +	ret = xenbus_alloc_evtchn(dev, &info->evtchn);
> +	if (ret)
> +		return ret;
> +	ret = bind_evtchn_to_irqhandler(info->evtchn, xenfb_event_handler,
> +					0, dev->devicetype, info);
> +	if (ret < 0) {
> +		xenbus_free_evtchn(dev, info->evtchn);
> +		xenbus_dev_fatal(dev, ret, "bind_evtchn_to_irqhandler");
> +		return ret;
> +	}
> +	info->irq = ret;
> +
> + again:
> +	ret = xenbus_transaction_start(&xbt);
> +	if (ret) {
> +		xenbus_dev_fatal(dev, ret, "starting transaction");
> +		return ret;
> +	}
> +	ret = xenbus_printf(xbt, dev->nodename, "page-ref", "%lu",
> +			    virt_to_mfn(info->page));
> +	if (ret)
> +		goto error_xenbus;
> +	ret = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
> +			    info->evtchn);
> +	if (ret)
> +		goto error_xenbus;
> +	ret = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
> +			    XEN_IO_PROTO_ABI_NATIVE);
> +	if (ret)
> +		goto error_xenbus;
> +	ret = xenbus_printf(xbt, dev->nodename, "feature-update", "1");
> +	if (ret)
> +		goto error_xenbus;
> +	ret = xenbus_transaction_end(xbt, 0);
> +	if (ret) {
> +		if (ret == -EAGAIN)
> +			goto again;
> +		xenbus_dev_fatal(dev, ret, "completing transaction");
> +		return ret;
> +	}
> +
> +	xenbus_switch_state(dev, XenbusStateInitialised);
> +	return 0;
> +
> + error_xenbus:
> +	xenbus_transaction_end(xbt, 1);
> +	xenbus_dev_fatal(dev, ret, "writing xenstore");
> +	return ret;
> +}
> +
> +static void xenfb_disconnect_backend(struct xenfb_info *info)
> +{
> +	if (info->irq >= 0)
> +		unbind_from_irqhandler(info->irq, info);
> +	info->irq = -1;
> +}
> +
> +static void xenfb_backend_changed(struct xenbus_device *dev,
> +				  enum xenbus_state backend_state)
> +{
> +	struct xenfb_info *info = dev->dev.driver_data;
> +	int val;
> +
> +	switch (backend_state) {
> +	case XenbusStateInitialising:
> +	case XenbusStateInitialised:
> +	case XenbusStateUnknown:
> +	case XenbusStateClosed:
> +		break;
> +
> +	case XenbusStateInitWait:
> +InitWait:
> +		xenbus_switch_state(dev, XenbusStateConnected);
> +		break;
> +
> +	case XenbusStateConnected:
> +		/*
> +		 * Work around xenbus race condition: If backend goes
> +		 * through InitWait to Connected fast enough, we can
> +		 * get Connected twice here.
> +		 */
> +		if (dev->state != XenbusStateConnected)
> +			goto InitWait; /* no InitWait seen yet, fudge it */
> +
> +		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,
> +				 "request-update", "%d", &val) < 0)
> +			val = 0;
> +		if (val)
> +			info->update_wanted = 1;
> +		break;
> +
> +	case XenbusStateClosing:
> +		xenbus_frontend_closed(dev);
> +		break;
> +	}
> +}
> +
> +static struct xenbus_device_id xenfb_ids[] = {
> +	{ "vfb" },
> +	{ "" }
> +};
> +
> +static struct xenbus_driver xenfb = {
> +	.name = "vfb",
> +	.owner = THIS_MODULE,
> +	.ids = xenfb_ids,
> +	.probe = xenfb_probe,
> +	.remove = xenfb_remove,
> +	.resume = xenfb_resume,
> +	.otherend_changed = xenfb_backend_changed,
> +};
> +
> +static int __init xenfb_init(void)
> +{
> +	if (!is_running_on_xen())
> +		return -ENODEV;
> +
> +	/* Nothing to do if running in dom0. */
> +	if (is_initial_xendomain())
> +		return -ENODEV;
> +
> +	return xenbus_register_frontend(&xenfb);
> +}
> +
> +static void __exit xenfb_cleanup(void)
> +{
> +	xenbus_unregister_driver(&xenfb);
> +}
> +
> +module_init(xenfb_init);
> +module_exit(xenfb_cleanup);
> +
> +MODULE_LICENSE("GPL");
> diff --git a/include/xen/interface/io/fbif.h b/include/xen/interface/io/fbif.h
> new file mode 100644
> index 0000000..5a934dd
> --- /dev/null
> +++ b/include/xen/interface/io/fbif.h
> @@ -0,0 +1,124 @@
> +/*
> + * fbif.h -- Xen virtual frame buffer device
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to
> + * deal in the Software without restriction, including without limitation the
> + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
> + * sell copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + *
> + * Copyright (C) 2005 Anthony Liguori <aliguori@xxxxxxxxxx>
> + * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@xxxxxxxxxx>
> + */
> +
> +#ifndef __XEN_PUBLIC_IO_FBIF_H__
> +#define __XEN_PUBLIC_IO_FBIF_H__
> +
> +/* Out events (frontend -> backend) */
> +
> +/*
> + * Out events may be sent only when requested by backend, and receipt
> + * of an unknown out event is an error.
> + */
> +
> +/* Event type 1 currently not used */
> +/*
> + * Framebuffer update notification event
> + * Capable frontend sets feature-update in xenstore.
> + * Backend requests it by setting request-update in xenstore.
> + */
> +#define XENFB_TYPE_UPDATE 2
> +
> +struct xenfb_update {
> +	uint8_t type;		/* XENFB_TYPE_UPDATE */
> +	int32_t x;		/* source x */
> +	int32_t y;		/* source y */
> +	int32_t width;		/* rect width */
> +	int32_t height;		/* rect height */
> +};
> +
> +#define XENFB_OUT_EVENT_SIZE 40
> +
> +union xenfb_out_event {
> +	uint8_t type;
> +	struct xenfb_update update;
> +	char pad[XENFB_OUT_EVENT_SIZE];
> +};
> +
> +/* In events (backend -> frontend) */
> +
> +/*
> + * Frontends should ignore unknown in events.
> + * No in events currently defined.
> + */
> +
> +#define XENFB_IN_EVENT_SIZE 40
> +
> +union xenfb_in_event {
> +	uint8_t type;
> +	char pad[XENFB_IN_EVENT_SIZE];
> +};
> +
> +/* shared page */
> +
> +#define XENFB_IN_RING_SIZE 1024
> +#define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE)
> +#define XENFB_IN_RING_OFFS 1024
> +#define XENFB_IN_RING(page) \
> +	((union xenfb_in_event *)((char *)(page) + XENFB_IN_RING_OFFS))
> +#define XENFB_IN_RING_REF(page, idx) \
> +	(XENFB_IN_RING((page))[(idx) % XENFB_IN_RING_LEN])
> +
> +#define XENFB_OUT_RING_SIZE 2048
> +#define XENFB_OUT_RING_LEN (XENFB_OUT_RING_SIZE / XENFB_OUT_EVENT_SIZE)
> +#define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE)
> +#define XENFB_OUT_RING(page) \
> +	((union xenfb_out_event *)((char *)(page) + XENFB_OUT_RING_OFFS))
> +#define XENFB_OUT_RING_REF(page, idx) \
> +	(XENFB_OUT_RING((page))[(idx) % XENFB_OUT_RING_LEN])
> +
> +struct xenfb_page {
> +	uint32_t in_cons, in_prod;
> +	uint32_t out_cons, out_prod;
> +
> +	int32_t width;          /* width of the framebuffer (in pixels) */
> +	int32_t height;         /* height of the framebuffer (in pixels) */
> +	uint32_t line_length;   /* length of a row of pixels (in bytes) */
> +	uint32_t mem_length;    /* length of the framebuffer (in bytes) */
> +	uint8_t depth;          /* depth of a pixel (in bits) */
> +
> +	/*
> +	 * Framebuffer page directory
> +	 *
> +	 * Each directory page holds PAGE_SIZE / sizeof(*pd)
> +	 * framebuffer pages, and can thus map up to PAGE_SIZE *
> +	 * PAGE_SIZE / sizeof(*pd) bytes.  With PAGE_SIZE == 4096 and
> +	 * sizeof(unsigned long) == 4, that's 4 Megs.  Two directory
> +	 * pages should be enough for a while.
> +	 */
> +	unsigned long pd[2];
> +};
> +
> +/*
> + * Wart: xenkbd needs to know resolution.  Put it here until a better
> + * solution is found, but don't leak it to the backend.
> + */
> +#ifdef __KERNEL__
> +#define XENFB_WIDTH 800
> +#define XENFB_HEIGHT 600
> +#define XENFB_DEPTH 32
> +#endif
> +
> +#endif
> diff --git a/include/xen/interface/io/kbdif.h b/include/xen/interface/io/kbdif.h
> new file mode 100644
> index 0000000..fb97f42
> --- /dev/null
> +++ b/include/xen/interface/io/kbdif.h
> @@ -0,0 +1,114 @@
> +/*
> + * kbdif.h -- Xen virtual keyboard/mouse
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to
> + * deal in the Software without restriction, including without limitation the
> + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
> + * sell copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + *
> + * Copyright (C) 2005 Anthony Liguori <aliguori@xxxxxxxxxx>
> + * Copyright (C) 2006 Red Hat, Inc., Markus Armbruster <armbru@xxxxxxxxxx>
> + */
> +
> +#ifndef __XEN_PUBLIC_IO_KBDIF_H__
> +#define __XEN_PUBLIC_IO_KBDIF_H__
> +
> +/* In events (backend -> frontend) */
> +
> +/*
> + * Frontends should ignore unknown in events.
> + */
> +
> +/* Pointer movement event */
> +#define XENKBD_TYPE_MOTION  1
> +/* Event type 2 currently not used */
> +/* Key event (includes pointer buttons) */
> +#define XENKBD_TYPE_KEY     3
> +/*
> + * Pointer position event
> + * Capable backend sets feature-abs-pointer in xenstore.
> + * Frontend requests ot instead of XENKBD_TYPE_MOTION by setting
> + * request-abs-update in xenstore.
> + */
> +#define XENKBD_TYPE_POS     4
> +
> +struct xenkbd_motion {
> +	uint8_t type;		/* XENKBD_TYPE_MOTION */
> +	int32_t rel_x;		/* relative X motion */
> +	int32_t rel_y;		/* relative Y motion */
> +};
> +
> +struct xenkbd_key {
> +	uint8_t type;		/* XENKBD_TYPE_KEY */
> +	uint8_t pressed;	/* 1 if pressed; 0 otherwise */
> +	uint32_t keycode;	/* KEY_* from linux/input.h */
> +};
> +
> +struct xenkbd_position {
> +	uint8_t type;		/* XENKBD_TYPE_POS */
> +	int32_t abs_x;		/* absolute X position (in FB pixels) */
> +	int32_t abs_y;		/* absolute Y position (in FB pixels) */
> +};
> +
> +#define XENKBD_IN_EVENT_SIZE 40
> +
> +union xenkbd_in_event {
> +	uint8_t type;
> +	struct xenkbd_motion motion;
> +	struct xenkbd_key key;
> +	struct xenkbd_position pos;
> +	char pad[XENKBD_IN_EVENT_SIZE];
> +};
> +
> +/* Out events (frontend -> backend) */
> +
> +/*
> + * Out events may be sent only when requested by backend, and receipt
> + * of an unknown out event is an error.
> + * No out events currently defined.
> + */
> +
> +#define XENKBD_OUT_EVENT_SIZE 40
> +
> +union xenkbd_out_event {
> +	uint8_t type;
> +	char pad[XENKBD_OUT_EVENT_SIZE];
> +};
> +
> +/* shared page */
> +
> +#define XENKBD_IN_RING_SIZE 2048
> +#define XENKBD_IN_RING_LEN (XENKBD_IN_RING_SIZE / XENKBD_IN_EVENT_SIZE)
> +#define XENKBD_IN_RING_OFFS 1024
> +#define XENKBD_IN_RING(page) \
> +	((union xenkbd_in_event *)((char *)(page) + XENKBD_IN_RING_OFFS))
> +#define XENKBD_IN_RING_REF(page, idx) \
> +	(XENKBD_IN_RING((page))[(idx) % XENKBD_IN_RING_LEN])
> +
> +#define XENKBD_OUT_RING_SIZE 1024
> +#define XENKBD_OUT_RING_LEN (XENKBD_OUT_RING_SIZE / XENKBD_OUT_EVENT_SIZE)
> +#define XENKBD_OUT_RING_OFFS (XENKBD_IN_RING_OFFS + XENKBD_IN_RING_SIZE)
> +#define XENKBD_OUT_RING(page) \
> +	((union xenkbd_out_event *)((char *)(page) + XENKBD_OUT_RING_OFFS))
> +#define XENKBD_OUT_RING_REF(page, idx) \
> +	(XENKBD_OUT_RING((page))[(idx) % XENKBD_OUT_RING_LEN])
> +
> +struct xenkbd_page {
> +	uint32_t in_cons, in_prod;
> +	uint32_t out_cons, out_prod;
> +};
> +
> +#endif
> _______________________________________________
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> https://lists.linux-foundation.org/mailman/listinfo/virtualization
>   

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