Example #1
0
void balloon_release_driver_page(struct page *page)
{
	unsigned long flags;

	balloon_lock(flags);
	balloon_append(page);
	driver_pages--;
	balloon_unlock(flags);

	schedule_work(&balloon_worker);
}
Example #2
0
static int __init balloon_init(void)
{
#if defined(CONFIG_X86) && defined(CONFIG_XEN) 
	unsigned long pfn;
	struct page *page;
#endif

	if (!is_running_on_xen())
		return -ENODEV;

	IPRINTK("Initialising balloon driver.\n");

#ifdef CONFIG_XEN
	current_pages = min(xen_start_info->nr_pages, max_pfn);
	totalram_pages = current_pages;
#else
	current_pages = totalram_pages;
#endif
	target_pages  = current_pages;
	balloon_low   = 0;
	balloon_high  = 0;
	driver_pages  = 0UL;
	hard_limit    = ~0UL;

	init_timer(&balloon_timer);
	balloon_timer.data = 0;
	balloon_timer.function = balloon_alarm;
    
/* don't include on bare-metal & FV guest */
#if defined(CONFIG_PROC_FS) && defined(CONFIG_XEN)
	if ((balloon_pde = create_xen_proc_entry("balloon", 0644)) == NULL) {
		WPRINTK("Unable to create /proc/xen/balloon.\n");
		return -1;
	}

	balloon_pde->read_proc  = balloon_read;
	balloon_pde->write_proc = balloon_write;
#endif
    
#if defined(CONFIG_X86) && defined(CONFIG_XEN) 
	/* Initialise the balloon with excess memory space. */
	for (pfn = xen_start_info->nr_pages; pfn < max_pfn; pfn++) {
		page = pfn_to_page(pfn);
		balloon_append(page);
	}
#endif

	target_watch.callback = watch_target;
	xenstore_notifier.notifier_call = balloon_init_watcher;

	register_xenstore_notifier(&xenstore_notifier);
    
	return 0;
}
Example #3
0
static int __init balloon_init(void)
{
	unsigned long pfn,num_physpages,max_pfn;
	struct page *page;

	if (!xen_domain())
		return -ENODEV;

	pr_info("xen_balloon: Initialising balloon driver.\n");

	num_physpages = get_num_physpages();

	if (xen_pv_domain())
               max_pfn = xen_start_info->nr_pages;
    	else
               max_pfn = num_physpages;

   	balloon_stats.current_pages = min(num_physpages,max_pfn);
    totalram_bias = balloon_stats.current_pages - totalram_pages;
    old_totalram_pages = totalram_pages;
	balloon_stats.target_pages  = balloon_stats.current_pages;
	balloon_stats.balloon_low   = 0;
	balloon_stats.balloon_high  = 0;
	balloon_stats.driver_pages  = 0UL;
    pr_info("current_pages=%luKB, totalram_pages=%luKB, totalram_bias=%luKB\n",balloon_stats.current_pages*4, totalram_pages*4, totalram_bias*4);

	init_timer(&balloon_timer);
	balloon_timer.data = 0;
	balloon_timer.function = balloon_alarm;

	register_balloon(&balloon_sysdev);

	/* Initialise the balloon with excess memory space. */
#ifdef CONFIG_PVM
	for (pfn = xen_start_info->nr_pages; pfn < max_pfn; pfn++) {
		page = pfn_to_page(pfn);
		if (!PageReserved(page))
			balloon_append(page);
	}
#endif
	target_watch.callback = watch_target;
	xenstore_notifier.notifier_call = balloon_init_watcher;

	register_xenstore_notifier(&xenstore_notifier);

	return 0;
}
Example #4
0
void free_empty_pages_and_pagevec(struct page **pagevec, int nr_pages)
{
	unsigned long flags;
	int i;

	if (pagevec == NULL)
		return;

	balloon_lock(flags);
	for (i = 0; i < nr_pages; i++) {
		BUG_ON(page_count(pagevec[i]) != 1);
		balloon_append(pagevec[i]);
	}
	balloon_unlock(flags);

	kfree(pagevec);

	schedule_work(&balloon_worker);
}
Example #5
0
static int __init balloon_init(void)
{
	unsigned long pfn;
	struct page *page;

	if (!xen_pv_domain())
		return -ENODEV;

	pr_info("xen_balloon: Initialising balloon driver.\n");

	balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
	totalram_pages   = balloon_stats.current_pages;
	balloon_stats.target_pages  = balloon_stats.current_pages;
	balloon_stats.balloon_low   = 0;
	balloon_stats.balloon_high  = 0;
	balloon_stats.driver_pages  = 0UL;
	balloon_stats.hard_limit    = ~0UL;

	init_timer(&balloon_timer);
	balloon_timer.data = 0;
	balloon_timer.function = balloon_alarm;

	register_balloon(&balloon_sysdev);

	/* Initialise the balloon with excess memory space. */
	for (pfn = xen_start_info->nr_pages; pfn < max_pfn; pfn++) {
		page = pfn_to_page(pfn);
		if (!PageReserved(page))
			balloon_append(page);
	}

	target_watch.callback = watch_target;
	xenstore_notifier.notifier_call = balloon_init_watcher;

	register_xenstore_notifier(&xenstore_notifier);

	return 0;
}
Example #6
0
static int dealloc_pte_fn(
	pte_t *pte, struct page *pmd_page, unsigned long addr, void *data)
{
	unsigned long mfn = pte_mfn(*pte);
	int ret;
	struct xen_memory_reservation reservation = {
		.nr_extents   = 1,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};
	set_xen_guest_handle(reservation.extent_start, &mfn);
	set_pte_at(&init_mm, addr, pte, __pte_ma(0));
	set_phys_to_machine(__pa(addr) >> PAGE_SHIFT, INVALID_P2M_ENTRY);
	ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
	BUG_ON(ret != 1);
	return 0;
}
#endif

struct page **alloc_empty_pages_and_pagevec(int nr_pages)
{
	unsigned long vaddr, flags;
	struct page *page, **pagevec;
	int i, ret;

	pagevec = kmalloc(sizeof(page) * nr_pages, GFP_KERNEL);
	if (pagevec == NULL)
		return NULL;

	for (i = 0; i < nr_pages; i++) {
		page = pagevec[i] = alloc_page(GFP_KERNEL);
		if (page == NULL)
			goto err;

		vaddr = (unsigned long)page_address(page);

		scrub_pages(vaddr, 1);

		balloon_lock(flags);

		if (xen_feature(XENFEAT_auto_translated_physmap)) {
			unsigned long gmfn = page_to_pfn(page);
			struct xen_memory_reservation reservation = {
				.nr_extents   = 1,
				.extent_order = 0,
				.domid        = DOMID_SELF
			};
			set_xen_guest_handle(reservation.extent_start, &gmfn);
			ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
						   &reservation);
			if (ret == 1)
				ret = 0; /* success */
		} else {
#ifdef CONFIG_XEN
			ret = apply_to_page_range(&init_mm, vaddr, PAGE_SIZE,
						  dealloc_pte_fn, NULL);
#else
			/* Cannot handle non-auto translate mode. */
			ret = 1;
#endif
		}

		if (ret != 0) {
			balloon_unlock(flags);
			__free_page(page);
			goto err;
		}

		totalram_pages = --current_pages;

		balloon_unlock(flags);
	}

 out:
	schedule_work(&balloon_worker);
#ifdef CONFIG_XEN
	flush_tlb_all();
#endif
	return pagevec;

 err:
	balloon_lock(flags);
	while (--i >= 0)
		balloon_append(pagevec[i]);
	balloon_unlock(flags);
	kfree(pagevec);
	pagevec = NULL;
	goto out;
}
Example #7
0
static int increase_reservation(unsigned long nr_pages)
{
	unsigned long  pfn, i, flags;
	struct page   *page;
	long           rc;
	struct xen_memory_reservation reservation = {
		.address_bits = 0,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};

	if (nr_pages > ARRAY_SIZE(frame_list))
		nr_pages = ARRAY_SIZE(frame_list);

	balloon_lock(flags);

	page = balloon_first_page();
	for (i = 0; i < nr_pages; i++) {
		BUG_ON(page == NULL);
		frame_list[i] = page_to_pfn(page);;
		page = balloon_next_page(page);
	}

	set_xen_guest_handle(reservation.extent_start, frame_list);
	reservation.nr_extents   = nr_pages;
	rc = HYPERVISOR_memory_op(
		XENMEM_populate_physmap, &reservation);
	if (rc < nr_pages) {
		int ret;
		/* We hit the Xen hard limit: reprobe. */
		set_xen_guest_handle(reservation.extent_start, frame_list);
		reservation.nr_extents   = rc;
		ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
				&reservation);
		BUG_ON(ret != rc);
		hard_limit = current_pages + rc - driver_pages;
		goto out;
	}

	for (i = 0; i < nr_pages; i++) {
		page = balloon_retrieve();
		BUG_ON(page == NULL);

		pfn = page_to_pfn(page);
		BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
		       phys_to_machine_mapping_valid(pfn));

		/* Update P->M and M->P tables. */
		set_phys_to_machine(pfn, frame_list[i]);

#ifdef CONFIG_XEN
		xen_machphys_update(frame_list[i], pfn);

		/* Link back into the page tables if not highmem. */
		if (pfn < max_low_pfn) {
			int ret;
			ret = HYPERVISOR_update_va_mapping(
				(unsigned long)__va(pfn << PAGE_SHIFT),
				pfn_pte_ma(frame_list[i], PAGE_KERNEL),
				0);
			BUG_ON(ret);
		}
#endif
		/* Relinquish the page back to the allocator. */
		ClearPageReserved(page);
		set_page_count(page, 1);
		__free_page(page);
	}

	current_pages += nr_pages;
	totalram_pages = current_pages;

 out:
	balloon_unlock(flags);

	return 0;
}

static int decrease_reservation(unsigned long nr_pages)
{
	unsigned long  pfn, i, flags;
	struct page   *page;
	void          *v;
	int            need_sleep = 0;
	int ret;
	struct xen_memory_reservation reservation = {
		.address_bits = 0,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};

	if (nr_pages > ARRAY_SIZE(frame_list))
		nr_pages = ARRAY_SIZE(frame_list);

	for (i = 0; i < nr_pages; i++) {
		if ((page = alloc_page(GFP_BALLOON)) == NULL) {
			nr_pages = i;
			need_sleep = 1;
			break;
		}

		pfn = page_to_pfn(page);
		frame_list[i] = pfn_to_mfn(pfn);

		if (!PageHighMem(page)) {
			v = phys_to_virt(pfn << PAGE_SHIFT);
			scrub_pages(v, 1);
#ifdef CONFIG_XEN
			ret = HYPERVISOR_update_va_mapping(
				(unsigned long)v, __pte_ma(0), 0);
			BUG_ON(ret);
#endif
		}
#ifdef CONFIG_XEN_SCRUB_PAGES
		else {
			v = kmap(page);
			scrub_pages(v, 1);
			kunmap(page);
		}
#endif
	}

#ifdef CONFIG_XEN
	/* Ensure that ballooned highmem pages don't have kmaps. */
	kmap_flush_unused();
	flush_tlb_all();
#endif

	balloon_lock(flags);

	/* No more mappings: invalidate P2M and add to balloon. */
	for (i = 0; i < nr_pages; i++) {
		pfn = mfn_to_pfn(frame_list[i]);
		set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
		balloon_append(pfn_to_page(pfn));
	}

	set_xen_guest_handle(reservation.extent_start, frame_list);
	reservation.nr_extents   = nr_pages;
	ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
	BUG_ON(ret != nr_pages);

	current_pages -= nr_pages;
	totalram_pages = current_pages;

	balloon_unlock(flags);

	return need_sleep;
}

/*
 * We avoid multiple worker processes conflicting via the balloon mutex.
 * We may of course race updates of the target counts (which are protected
 * by the balloon lock), or with changes to the Xen hard limit, but we will
 * recover from these in time.
 */
static void balloon_process(void *unused)
{
	int need_sleep = 0;
	long credit;

	down(&balloon_mutex);

	do {
		credit = current_target() - current_pages;
		if (credit > 0)
			need_sleep = (increase_reservation(credit) != 0);
		if (credit < 0)
			need_sleep = (decrease_reservation(-credit) != 0);

#ifndef CONFIG_PREEMPT
		if (need_resched())
			schedule();
#endif
	} while ((credit != 0) && !need_sleep);

	/* Schedule more work if there is some still to be done. */
	if (current_target() != current_pages)
		mod_timer(&balloon_timer, jiffies + HZ);

	up(&balloon_mutex);
}
Example #8
0
static int increase_reservation(unsigned long nr_pages)
{
	unsigned long  pfn, i, flags;
	struct page   *page;
	long           rc;
	struct xen_memory_reservation reservation = {
		.address_bits = 0,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};

	if (nr_pages > ARRAY_SIZE(frame_list))
		nr_pages = ARRAY_SIZE(frame_list);

	spin_lock_irqsave(&balloon_lock, flags);

	page = balloon_first_page();
	for (i = 0; i < nr_pages; i++) {
		BUG_ON(page == NULL);
		frame_list[i] = page_to_pfn(page);
		page = balloon_next_page(page);
	}

	set_xen_guest_handle(reservation.extent_start, frame_list);
	reservation.nr_extents = nr_pages;
	rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
	if (rc < 0)
		goto out;

	for (i = 0; i < rc; i++) {
		page = balloon_retrieve();
		BUG_ON(page == NULL);

		pfn = page_to_pfn(page);
		BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
		       phys_to_machine_mapping_valid(pfn));

		set_phys_to_machine(pfn, frame_list[i]);

		/* Link back into the page tables if not highmem. */
#ifdef CONFIG_PVM
		if (!xen_hvm_domain() && pfn < max_low_pfn) {
			int ret;
			ret = HYPERVISOR_update_va_mapping(
				(unsigned long)__va(pfn << PAGE_SHIFT),
				mfn_pte(frame_list[i], PAGE_KERNEL),
				0);
			BUG_ON(ret);
		}
#endif
		/* Relinquish the page back to the allocator. */
		ClearPageReserved(page);
		init_page_count(page);
		__free_page(page);
	}

	balloon_stats.current_pages += rc;
   	if (old_totalram_pages + rc < totalram_pages)
   	{
        printk(KERN_INFO "old_totalram=%luKB, totalram_pages=%luKB\n", old_totalram_pages*4, totalram_pages*4);
       	balloon_stats.current_pages = totalram_pages + totalram_bias;
        printk(KERN_INFO "when ballooning, the mem online! totalram=%luKB, current=%luKB\n", totalram_pages*4, balloon_stats.current_pages*4);
   	}
   	old_totalram_pages = totalram_pages;
	

 out:
	spin_unlock_irqrestore(&balloon_lock, flags);

	return rc < 0 ? rc : rc != nr_pages;
}

static int decrease_reservation(unsigned long nr_pages)
{
	unsigned long  pfn, i, flags;
	struct page   *page;
	int            need_sleep = 0;
	int ret;
	struct xen_memory_reservation reservation = {
		.address_bits = 0,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};

	if (nr_pages > ARRAY_SIZE(frame_list))
		nr_pages = ARRAY_SIZE(frame_list);

	for (i = 0; i < nr_pages; i++) {
		if ((page = alloc_page(GFP_BALLOON)) == NULL) {
			nr_pages = i;
			need_sleep = 1;
			break;
		}

		pfn = page_to_pfn(page);
		frame_list[i] = pfn_to_mfn(pfn);

		scrub_page(page);

		if (!xen_hvm_domain() && !PageHighMem(page)) {
			ret = HYPERVISOR_update_va_mapping(
				(unsigned long)__va(pfn << PAGE_SHIFT),
				__pte_ma(0), 0);
			BUG_ON(ret);
                }

	}

	/* Ensure that ballooned highmem pages don't have kmaps. */
#ifdef CONFIG_PVM
	kmap_flush_unused();
	flush_tlb_all();
#endif
	spin_lock_irqsave(&balloon_lock, flags);

	/* No more mappings: invalidate P2M and add to balloon. */
	for (i = 0; i < nr_pages; i++) {
		pfn = mfn_to_pfn(frame_list[i]);
		set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
		balloon_append(pfn_to_page(pfn));
	}

	set_xen_guest_handle(reservation.extent_start, frame_list);
	reservation.nr_extents   = nr_pages;
	ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
	BUG_ON(ret != nr_pages);

	balloon_stats.current_pages -= nr_pages;
   	if(old_totalram_pages < totalram_pages + nr_pages)
   	{
        printk(KERN_INFO "old_totalram=%luKB, totalram_pages=%luKB\n", old_totalram_pages*4, totalram_pages*4);
       	balloon_stats.current_pages = totalram_pages + totalram_bias;
        printk(KERN_INFO "when ballooning, the mem online! totalram=%luKB, current=%luKB\n", totalram_pages*4, balloon_stats.current_pages*4);
   	}
   	old_totalram_pages = totalram_pages;
	
	spin_unlock_irqrestore(&balloon_lock, flags);

	return need_sleep;
}

/*
 * We avoid multiple worker processes conflicting via the balloon mutex.
 * We may of course race updates of the target counts (which are protected
 * by the balloon lock), or with changes to the Xen hard limit, but we will
 * recover from these in time.
 */
static void balloon_process(struct work_struct *work)
{
	int need_sleep = 0;
	long credit;
    long total_increase = 0;
	char buffer[16];

	mutex_lock(&balloon_mutex);
    printk(KERN_INFO "totalram_pages=%luKB, current_pages=%luKB,totalram_bias=%luKB\n", totalram_pages*4, balloon_stats.current_pages*4, totalram_bias*4);

    if (totalram_pages > old_totalram_pages)
    {
        //TODO:Just know that totalram_pages will increase.
        total_increase = (totalram_pages - old_totalram_pages) % GB2PAGE;
        if (totalram_bias > total_increase )
        {
            totalram_bias = totalram_bias - total_increase;
        }
        balloon_stats.current_pages = totalram_pages + totalram_bias;
        old_totalram_pages = totalram_pages;
    }
    printk(KERN_INFO "totalram_pages=%luKB, current_pages=%luKB, totalram_bias=%luKB,total_increase=%ld\n", totalram_pages*4, balloon_stats.current_pages*4, totalram_bias*4, total_increase*4);
	xenbus_write(XBT_NIL, "control/uvp", "Balloon_flag", "1");
	do {
		credit = current_target() - balloon_stats.current_pages;
		if (credit > 0)
			need_sleep = (increase_reservation(credit) != 0);
		if (credit < 0)
			need_sleep = (decrease_reservation(-credit) != 0);

#ifndef CONFIG_PREEMPT
		if (need_resched())
			schedule();
#endif
	} while ((credit != 0) && !need_sleep);

	/* Schedule more work if there is some still to be done. */
	if (current_target() != balloon_stats.current_pages)
	{
		mod_timer(&balloon_timer, jiffies + HZ);
		sprintf(buffer,"%lu",balloon_stats.current_pages<<(PAGE_SHIFT-10));
		xenbus_write(XBT_NIL, "memory", "target", buffer);
	}
	xenbus_write(XBT_NIL, "control/uvp", "Balloon_flag", "0");
	mutex_unlock(&balloon_mutex);
}