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From: Daniel Kiper on 6 Aug 2010 07:50
Hi,

I am sending this e-mail once again because it probably
has been lost in abyss of Xen-devel/LKLM list.

Here is the second version of memory hotplug support
for Xen guests patch. This one cleanly applies to
git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git
repository, xen/memory-hotplug head.

Changes:
- /sys/devices/system/memory/probe interface has been removed;
/sys/devices/system/xen_memory/xen_memory0/{target,target_kb}
are much better (I forgot about them),
- most of the code have been moved to drivers/xen/balloon.c,
- this changes forced me to export hotadd_new_pgdat and
rollback_node_hotadd function from mm/memory_hotplug.c;
could it be accepted by mm/memory_hotplug.c maintainers ???
- PV on HVM mode is supported now; it was tested on
git://xenbits.xen.org/people/sstabellini/linux-pvhvm.git
repository, 2.6.34-pvhvm head,
- most of Jeremy suggestions have been applied.

On Wed, Jul 28, 2010 at 11:36:29AM +0400, Vasiliy G Tolstov wrote:
[...]
> Work's fine with opensuse 11.3 (dom0 and domU)

Thx.

On Thu, Jul 29, 2010 at 12:39:52PM -0700, Jeremy Fitzhardinge wrote:
> On 07/26/2010 05:41 PM, Daniel Kiper wrote:
> >Hi,
> >
> >Currently there is fully working version.
> >It has been tested on Xen Ver. 4.0.0 in PV
> >guest i386/x86_64 with Linux kernel Ver. 2.6.32.16
> >and Ver. 2.6.34.1. This patch cleanly applys
> >to Ver. 2.6.34.1
>
> Thanks. I've pushed this into xen.git as xen/memory-hotplug so people
> can play with it more easily (but I haven't merged it into any of the
> other branches yet).

Thx.

> >+#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
> >+static inline unsigned long current_target(void)
> >+{
> >+ return balloon_stats.target_pages;
>
> Why does this need its own version?

Because original version return values not bigger
then initial memory allocation which does not allow
memory hotplug to function.

> >+int __ref xen_add_memory(int nid, u64 start, u64 size)
> >+{
> >+ pg_data_t *pgdat = NULL;
> >+ int new_pgdat = 0, ret;
> >+
> >+ lock_system_sleep();
> >+
> >+ if (!node_online(nid)) {
> >+ pgdat = hotadd_new_pgdat(nid, start);
> >+ ret = -ENOMEM;
> >+ if (!pgdat)
> >+ goto out;
> >+ new_pgdat = 1;
> >+ }
> >+
> >+ /* call arch's memory hotadd */
> >+ ret = arch_add_memory(nid, start, size);
> >+
> >+ if (ret< 0)
> >+ goto error;
> >+
> >+ /* we online node here. we can't roll back from here. */
> >+ node_set_online(nid);
> >+
> >+ if (new_pgdat) {
> >+ ret = register_one_node(nid);
> >+ /*
> >+ * If sysfs file of new node can't create, cpu on the node
> >+ * can't be hot-added. There is no rollback way now.
> >+ * So, check by BUG_ON() to catch it reluctantly..
> >+ */
> >+ BUG_ON(ret);
> >+ }
>
> This doesn't seem to be doing anything particularly xen-specific.

In general it could be generic however I do not know
it will be useful for others. If this function would
be accepted by mm/memory_hotplug.c maintainers we could
move it there. I removed from original add_memory funtion
resource allocation (and deallocation after error), which
must be done before XENMEM_populate_physmap in Xen. xen_add_memory
is called after physmap is fully populated.

If you have a questions please drop me a line.

Daniel

Signed-off-by: Daniel Kiper <dkiper(a)net-space.pl>
---
arch/x86/Kconfig | 2 +-
drivers/base/memory.c | 23 ---
drivers/xen/Kconfig | 2 +-
drivers/xen/balloon.c | 416 ++++++++++++++++++++++------------------
include/linux/memory_hotplug.h | 10 +-
include/xen/balloon.h | 6 -
mm/Kconfig | 9 -
mm/memory_hotplug.c | 146 +--------------
8 files changed, 240 insertions(+), 374 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 38434da..beb1aa7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1273,7 +1273,7 @@ config ARCH_SELECT_MEMORY_MODEL
depends on ARCH_SPARSEMEM_ENABLE

config ARCH_MEMORY_PROBE
- def_bool y
+ def_bool X86_64 && !XEN
depends on MEMORY_HOTPLUG

config ILLEGAL_POINTER_VALUE
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 709457b..933442f 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -27,14 +27,6 @@
#include <asm/atomic.h>
#include <asm/uaccess.h>

-#ifdef CONFIG_XEN_MEMORY_HOTPLUG
-#include <xen/xen.h>
-#endif
-
-#if defined(CONFIG_XEN_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
-#include <xen/balloon.h>
-#endif
-
#define MEMORY_CLASS_NAME "memory"

static struct sysdev_class memory_sysdev_class = {
@@ -223,10 +215,6 @@ memory_block_action(struct memory_block *mem, unsigned long action)
case MEM_ONLINE:
start_pfn = page_to_pfn(first_page);
ret = online_pages(start_pfn, PAGES_PER_SECTION);
-#if defined(CONFIG_XEN_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
- if (xen_domain() && !ret)
- balloon_update_stats(PAGES_PER_SECTION);
-#endif
break;
case MEM_OFFLINE:
mem->state = MEM_GOING_OFFLINE;
@@ -237,10 +225,6 @@ memory_block_action(struct memory_block *mem, unsigned long action)
mem->state = old_state;
break;
}
-#if defined(CONFIG_XEN_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
- if (xen_domain())
- balloon_update_stats(-PAGES_PER_SECTION);
-#endif
break;
default:
WARN(1, KERN_WARNING "%s(%p, %ld) unknown action: %ld\n",
@@ -357,13 +341,6 @@ memory_probe_store(struct class *class, struct class_attribute *attr,

phys_addr = simple_strtoull(buf, NULL, 0);

-#ifdef CONFIG_XEN_MEMORY_HOTPLUG
- if (xen_domain()) {
- ret = xen_memory_probe(phys_addr);
- return ret ? ret : count;
- }
-#endif
-
nid = memory_add_physaddr_to_nid(phys_addr);
ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT);

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 9713048..4f35eaf 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -11,8 +11,8 @@ config XEN_BALLOON

config XEN_BALLOON_MEMORY_HOTPLUG
bool "Xen memory balloon driver with memory hotplug support"
- depends on EXPERIMENTAL && XEN_BALLOON && MEMORY_HOTPLUG
default n
+ depends on XEN_BALLOON && MEMORY_HOTPLUG
help
Xen memory balloon driver with memory hotplug support allows expanding
memory available for the system above limit declared at system startup.
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index f80bba0..31edc26 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -45,6 +45,8 @@
#include <linux/list.h>
#include <linux/sysdev.h>
#include <linux/gfp.h>
+#include <linux/memory.h>
+#include <linux/suspend.h>

#include <asm/page.h>
#include <asm/pgalloc.h>
@@ -62,10 +64,6 @@
#include <xen/features.h>
#include <xen/page.h>

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
-#include <linux/memory.h>
-#endif
-
#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))

#define BALLOON_CLASS_NAME "xen_memory"
@@ -199,6 +197,196 @@ static inline unsigned long current_target(void)
{
return balloon_stats.target_pages;
}
+
+static inline u64 is_memory_resource_reserved(void)
+{
+ return balloon_stats.hotplug_start_paddr;
+}
+
+/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+static int __ref xen_add_memory(int nid, u64 start, u64 size)
+{
+ pg_data_t *pgdat = NULL;
+ int new_pgdat = 0, ret;
+
+ lock_system_sleep();
+
+ if (!node_online(nid)) {
+ pgdat = hotadd_new_pgdat(nid, start);
+ ret = -ENOMEM;
+ if (!pgdat)
+ goto out;
+ new_pgdat = 1;
+ }
+
+ /* call arch's memory hotadd */
+ ret = arch_add_memory(nid, start, size);
+
+ if (ret < 0)
+ goto error;
+
+ /* we online node here. we can't roll back from here. */
+ node_set_online(nid);
+
+ if (new_pgdat) {
+ ret = register_one_node(nid);
+ /*
+ * If sysfs file of new node can't create, cpu on the node
+ * can't be hot-added. There is no rollback way now.
+ * So, check by BUG_ON() to catch it reluctantly..
+ */
+ BUG_ON(ret);
+ }
+
+ goto out;
+
+error:
+ /* rollback pgdat allocation */
+ if (new_pgdat)
+ rollback_node_hotadd(nid, pgdat);
+
+out:
+ unlock_system_sleep();
+ return ret;
+}
+
+static int allocate_additional_memory(unsigned long nr_pages)
+{
+ long rc;
+ resource_size_t r_min, r_size;
+ struct resource *r;
+ struct xen_memory_reservation reservation = {
+ .address_bits = 0,
+ .extent_order = 0,
+ .domid = DOMID_SELF
+ };
+ unsigned long flags, i, pfn;
+
+ if (nr_pages > ARRAY_SIZE(frame_list))
+ nr_pages = ARRAY_SIZE(frame_list);
+
+ spin_lock_irqsave(&balloon_lock, flags);
+
+ if (!is_memory_resource_reserved()) {
+
+ /*
+ * Look for first unused memory region starting at page
+ * boundary. Skip last memory section created at boot time
+ * becuase it may contains unused memory pages with PG_reserved
+ * bit not set (online_pages require PG_reserved bit set).
+ */
+
+ r = kzalloc(sizeof(struct resource), GFP_KERNEL);
+
+ if (!r) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ r->name = "System RAM";
+ r->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ r_min = PFN_PHYS(section_nr_to_pfn(pfn_to_section_nr(balloon_stats.boot_max_pfn) + 1));
+ r_size = (balloon_stats.target_pages - balloon_stats.current_pages) << PAGE_SHIFT;
+
+ rc = allocate_resource(&iomem_resource, r, r_size, r_min,
+ ULONG_MAX, PAGE_SIZE, NULL, NULL);
+
+ if (rc < 0) {
+ kfree(r);
+ goto out;
+ }
+
+ balloon_stats.hotplug_start_paddr = r->start;
+ }
+
+ pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr + balloon_stats.hotplug_size);
+
+ for (i = 0; i < nr_pages; ++i, ++pfn)
+ frame_list[i] = pfn;
+
+ 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;
+
+ pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr + balloon_stats.hotplug_size);
+
+ for (i = 0; i < rc; ++i, ++pfn) {
+ BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
+ phys_to_machine_mapping_valid(pfn));
+ set_phys_to_machine(pfn, frame_list[i]);
+ }
+
+ balloon_stats.hotplug_size += rc << PAGE_SHIFT;
+ balloon_stats.current_pages += rc;
+
+out:
+ spin_unlock_irqrestore(&balloon_lock, flags);
+
+ return rc < 0 ? rc : rc != nr_pages;
+}
+
+static void hotplug_allocated_memory(void)
+{
+ int nid, ret;
+ struct memory_block *mem;
+ unsigned long pfn, pfn_limit;
+
+ nid = memory_add_physaddr_to_nid(balloon_stats.hotplug_start_paddr);
+
+ ret = xen_add_memory(nid, balloon_stats.hotplug_start_paddr,
+ balloon_stats.hotplug_size);
+
+ if (ret) {
+ pr_err("%s: xen_add_memory: Memory hotplug failed: %i\n",
+ __func__, ret);
+ goto error;
+ }
+
+ if (xen_pv_domain()) {
+ pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr);
+ pfn_limit = pfn + (balloon_stats.hotplug_size >> PAGE_SHIFT);
+
+ for (; pfn < pfn_limit; ++pfn)
+ if (!PageHighMem(pfn_to_page(pfn)))
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)__va(pfn << PAGE_SHIFT),
+ mfn_pte(pfn_to_mfn(pfn), PAGE_KERNEL), 0));
+ }
+
+ ret = online_pages(PFN_DOWN(balloon_stats.hotplug_start_paddr),
+ balloon_stats.hotplug_size >> PAGE_SHIFT);
+
+ if (ret) {
+ pr_err("%s: online_pages: Failed: %i\n", __func__, ret);
+ goto error;
+ }
+
+ pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr);
+ pfn_limit = pfn + (balloon_stats.hotplug_size >> PAGE_SHIFT);
+
+ for (; pfn < pfn_limit; pfn += PAGES_PER_SECTION) {
+ mem = find_memory_block(__pfn_to_section(pfn));
+ BUG_ON(!mem);
+ BUG_ON(!present_section_nr(mem->phys_index));
+ mutex_lock(&mem->state_mutex);
+ mem->state = MEM_ONLINE;
+ mutex_unlock(&mem->state_mutex);
+ }
+
+ goto out;
+
+error:
+ balloon_stats.current_pages -= balloon_stats.hotplug_size >> PAGE_SHIFT;
+ balloon_stats.target_pages -= balloon_stats.hotplug_size >> PAGE_SHIFT;
+
+out:
+ balloon_stats.hotplug_start_paddr = 0;
+ balloon_stats.hotplug_size = 0;
+}
#else
static unsigned long current_target(void)
{
@@ -211,12 +399,26 @@ static unsigned long current_target(void)

return target;
}
+
+static inline u64 is_memory_resource_reserved(void)
+{
+ return 0;
+}
+
+static inline int allocate_additional_memory(unsigned long nr_pages)
+{
+ return 0;
+}
+
+static inline void hotplug_allocated_memory(void)
+{
+}
#endif

static int increase_reservation(unsigned long nr_pages)
{
- unsigned long uninitialized_var(pfn), i, flags;
- struct page *uninitialized_var(page);
+ unsigned long pfn, i, flags;
+ struct page *page;
long rc;
struct xen_memory_reservation reservation = {
.address_bits = 0,
@@ -224,63 +426,11 @@ static int increase_reservation(unsigned long nr_pages)
.domid = DOMID_SELF
};

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- resource_size_t r_min, r_size;
- struct resource *r;
-#endif
-
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);

spin_lock_irqsave(&balloon_lock, flags);

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- if (!balloon_stats.balloon_low && !balloon_stats.balloon_high) {
- if (!balloon_stats.hotplug_start_paddr) {
-
- /*
- * Look for first unused memory region starting
- * at page boundary. Skip last memory section created
- * at boot time becuase it may contains unused memory
- * pages with PG_reserved bit not set (online_pages
- * require PG_reserved bit set).
- */
-
- r = kzalloc(sizeof(struct resource), GFP_KERNEL);
-
- if (!r) {
- rc = -ENOMEM;
- goto out;
- }
-
- r->name = "System RAM";
- r->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
- r_min = PFN_PHYS(section_nr_to_pfn(pfn_to_section_nr(balloon_stats.boot_max_pfn) + 1));
- r_size = (balloon_stats.target_pages - balloon_stats.current_pages) << PAGE_SHIFT;
-
- rc = allocate_resource(&iomem_resource, r,
- r_size, r_min, ULONG_MAX,
- PAGE_SIZE, NULL, NULL);
-
- if (rc < 0) {
- kfree(r);
- goto out;
- }
-
- balloon_stats.hotplug_start_paddr = r->start;
- }
-
- pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr +
- balloon_stats.hotplug_size);
-
- for (i = 0; i < nr_pages; ++i, ++pfn)
- frame_list[i] = pfn;
-
- pfn -= nr_pages + 1;
- goto populate_physmap;
- }
-#endif
-
page = balloon_first_page();
for (i = 0; i < nr_pages; i++) {
BUG_ON(page == NULL);
@@ -288,9 +438,6 @@ static int increase_reservation(unsigned long nr_pages)
page = balloon_next_page(page);
}

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
-populate_physmap:
-#endif
set_xen_guest_handle(reservation.extent_start, frame_list);
reservation.nr_extents = nr_pages;
rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
@@ -298,33 +445,17 @@ populate_physmap:
goto out;

for (i = 0; i < rc; i++) {
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- if (balloon_stats.hotplug_start_paddr) {
- ++pfn;
- goto set_p2m;
- }
-#endif
-
page = balloon_retrieve();
BUG_ON(page == NULL);

pfn = page_to_pfn(page);
-
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
-set_p2m:
-#endif
BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
phys_to_machine_mapping_valid(pfn));

set_phys_to_machine(pfn, frame_list[i]);

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- if (balloon_stats.hotplug_start_paddr)
- continue;
-#endif
-
/* Link back into the page tables if not highmem. */
- if (!PageHighMem(page)) {
+ if (xen_pv_domain() && !PageHighMem(page)) {
int ret;
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
@@ -339,11 +470,6 @@ set_p2m:
__free_page(page);
}

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- if (balloon_stats.hotplug_start_paddr)
- balloon_stats.hotplug_size += rc << PAGE_SHIFT;
-#endif
-
balloon_stats.current_pages += rc;

out:
@@ -379,7 +505,7 @@ static int decrease_reservation(unsigned long nr_pages)

scrub_page(page);

- if (!PageHighMem(page)) {
+ if (xen_pv_domain() && !PageHighMem(page)) {
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
__pte_ma(0), 0);
@@ -424,18 +550,18 @@ static void balloon_process(struct work_struct *work)
int need_sleep = 0;
long credit;

-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- int nid, ret;
- struct memory_block *mem;
- unsigned long pfn, pfn_limit;
-#endif
-
mutex_lock(&balloon_mutex);

do {
credit = current_target() - balloon_stats.current_pages;
- if (credit > 0)
- need_sleep = (increase_reservation(credit) != 0);
+
+ if (credit > 0) {
+ if (balloon_stats.balloon_low || balloon_stats.balloon_high)
+ need_sleep = (increase_reservation(credit) != 0);
+ else
+ need_sleep = (allocate_additional_memory(credit) != 0);
+ }
+
if (credit < 0)
need_sleep = (decrease_reservation(-credit) != 0);

@@ -448,93 +574,12 @@ static void balloon_process(struct work_struct *work)
/* Schedule more work if there is some still to be done. */
if (current_target() != balloon_stats.current_pages)
mod_timer(&balloon_timer, jiffies + HZ);
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- else if (balloon_stats.hotplug_start_paddr) {
- nid = memory_add_physaddr_to_nid(balloon_stats.hotplug_start_paddr);
-
- ret = xen_add_memory(nid, balloon_stats.hotplug_start_paddr,
- balloon_stats.hotplug_size);
-
- if (ret) {
- printk(KERN_ERR "%s: xen_add_memory: "
- "Memory hotplug failed: %i\n",
- __func__, ret);
- goto error;
- }
-
- pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr);
- pfn_limit = pfn + (balloon_stats.hotplug_size >> PAGE_SHIFT);
-
- for (; pfn < pfn_limit; ++pfn)
- if (!PageHighMem(pfn_to_page(pfn)))
- BUG_ON(HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- mfn_pte(pfn_to_mfn(pfn), PAGE_KERNEL), 0));
-
- ret = online_pages(PFN_DOWN(balloon_stats.hotplug_start_paddr),
- balloon_stats.hotplug_size >> PAGE_SHIFT);
-
- if (ret) {
- printk(KERN_ERR "%s: online_pages: Failed: %i\n",
- __func__, ret);
- goto error;
- }
-
- pfn = PFN_DOWN(balloon_stats.hotplug_start_paddr);
- pfn_limit = pfn + (balloon_stats.hotplug_size >> PAGE_SHIFT);
-
- for (; pfn < pfn_limit; pfn += PAGES_PER_SECTION) {
- mem = find_memory_block(__pfn_to_section(pfn));
- BUG_ON(!mem);
- BUG_ON(!present_section_nr(mem->phys_index));
- mutex_lock(&mem->state_mutex);
- mem->state = MEM_ONLINE;
- mutex_unlock(&mem->state_mutex);
- }
-
- goto out;
-
-error:
- balloon_stats.current_pages -= balloon_stats.hotplug_size >> PAGE_SHIFT;
- balloon_stats.target_pages -= balloon_stats.hotplug_size >> PAGE_SHIFT;
-
-out:
- balloon_stats.hotplug_start_paddr = 0;
- balloon_stats.hotplug_size = 0;
- }
-#endif
+ else if (is_memory_resource_reserved())
+ hotplug_allocated_memory();

mutex_unlock(&balloon_mutex);
}

-#ifdef CONFIG_XEN_MEMORY_HOTPLUG
-
-/* Resets the Xen limit, sets new target, and kicks off processing. */
-static void balloon_set_new_target(unsigned long target)
-{
- mutex_lock(&balloon_mutex);
- balloon_stats.target_pages = target;
- mutex_unlock(&balloon_mutex);
-
- schedule_work(&balloon_worker);
-}
-
-void balloon_update_stats(long nr_pages)
-{
- mutex_lock(&balloon_mutex);
-
- balloon_stats.current_pages += nr_pages;
- balloon_stats.target_pages += nr_pages;
-
- xenbus_printf(XBT_NIL, "memory", "target", "%llu",
- (unsigned long long)balloon_stats.target_pages << (PAGE_SHIFT - 10));
-
- mutex_unlock(&balloon_mutex);
-}
-EXPORT_SYMBOL_GPL(balloon_update_stats);
-
-#else
-
/* Resets the Xen limit, sets new target, and kicks off processing. */
static void balloon_set_new_target(unsigned long target)
{
@@ -543,8 +588,6 @@ static void balloon_set_new_target(unsigned long target)
schedule_work(&balloon_worker);
}

-#endif
-
static struct xenbus_watch target_watch =
{
.node = "memory/target"
@@ -589,12 +632,16 @@ static int __init balloon_init(void)
unsigned long pfn;
struct page *page;

- if (!xen_pv_domain())
+ if (!xen_domain())
return -ENODEV;

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

- balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
+ if (xen_pv_domain())
+ balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
+ else
+ balloon_stats.current_pages = max_pfn;
+
balloon_stats.target_pages = balloon_stats.current_pages;
balloon_stats.balloon_low = 0;
balloon_stats.balloon_high = 0;
@@ -613,11 +660,12 @@ static int __init balloon_init(void)
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);
- }
+ if (xen_pv_domain())
+ 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;
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 04e67b8..6652eae 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -202,6 +202,8 @@ static inline int is_mem_section_removable(unsigned long pfn,
}
#endif /* CONFIG_MEMORY_HOTREMOVE */

+extern pg_data_t *hotadd_new_pgdat(int nid, u64 start);
+extern void rollback_node_hotadd(int nid, pg_data_t *pgdat);
extern int add_memory(int nid, u64 start, u64 size);
extern int arch_add_memory(int nid, u64 start, u64 size);
extern int remove_memory(u64 start, u64 size);
@@ -211,12 +213,4 @@ extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
unsigned long pnum);

-#if defined(CONFIG_XEN_MEMORY_HOTPLUG) || defined(CONFIG_XEN_BALLOON_MEMORY_HOTPLUG)
-extern int xen_add_memory(int nid, u64 start, u64 size);
-#endif
-
-#ifdef CONFIG_XEN_MEMORY_HOTPLUG
-extern int xen_memory_probe(u64 phys_addr);
-#endif
-
#endif /* __LINUX_MEMORY_HOTPLUG_H */
diff --git a/include/xen/balloon.h b/include/xen/balloon.h
deleted file mode 100644
index 84b17b7..0000000
--- a/include/xen/balloon.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef _XEN_BALLOON_H
-#define _XEN_BALLOON_H
-
-extern void balloon_update_stats(long nr_pages);
-
-#endif /* _XEN_BALLOON_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index b04f3a8..9c61158 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -144,15 +144,6 @@ config MEMORY_HOTREMOVE
depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
depends on MIGRATION

-config XEN_MEMORY_HOTPLUG
- bool "Allow for memory hot-add in Xen guests"
- depends on EXPERIMENTAL && ARCH_MEMORY_PROBE && XEN
- default n
- help
- Memory hotplug allows expanding memory available for the system
- above limit declared at system startup. It is very useful on critical
- systems which require long run without rebooting.
-
#
# If we have space for more page flags then we can enable additional
# optimizations and functionality.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 1c73703..143e03c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -32,14 +32,6 @@

#include <asm/tlbflush.h>

-#ifdef CONFIG_XEN_MEMORY_HOTPLUG
-#include <asm/xen/hypercall.h>
-#include <xen/interface/xen.h>
-#include <xen/interface/memory.h>
-#include <xen/features.h>
-#include <xen/page.h>
-#endif
-
#include "internal.h"

/* add this memory to iomem resource */
@@ -461,7 +453,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */

/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
-static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
+pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
{
struct pglist_data *pgdat;
unsigned long zones_size[MAX_NR_ZONES] = {0};
@@ -481,13 +473,15 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)

return pgdat;
}
+EXPORT_SYMBOL_GPL(hotadd_new_pgdat);

-static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
+void rollback_node_hotadd(int nid, pg_data_t *pgdat)
{
arch_refresh_nodedata(nid, NULL);
arch_free_nodedata(pgdat);
return;
}
+EXPORT_SYMBOL_GPL(rollback_node_hotadd);


/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
@@ -550,138 +544,6 @@ out:
}
EXPORT_SYMBOL_GPL(add_memory);

-#if defined(CONFIG_XEN_MEMORY_HOTPLUG) || defined(CONFIG_XEN_BALLOON_MEMORY_HOTPLUG)
-/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
-int __ref xen_add_memory(int nid, u64 start, u64 size)
-{
- pg_data_t *pgdat = NULL;
- int new_pgdat = 0, ret;
-
- lock_system_sleep();
-
- if (!node_online(nid)) {
- pgdat = hotadd_new_pgdat(nid, start);
- ret = -ENOMEM;
- if (!pgdat)
- goto out;
- new_pgdat = 1;
- }
-
- /* call arch's memory hotadd */
- ret = arch_add_memory(nid, start, size);
-
- if (ret < 0)
- goto error;
-
- /* we online node here. we can't roll back from here. */
- node_set_online(nid);
-
- if (new_pgdat) {
- ret = register_one_node(nid);
- /*
- * If sysfs file of new node can't create, cpu on the node
- * can't be hot-added. There is no rollback way now.
- * So, check by BUG_ON() to catch it reluctantly..
- */
- BUG_ON(ret);
- }
-
- goto out;
-
-error:
- /* rollback pgdat allocation */
- if (new_pgdat)
- rollback_node_hotadd(nid, pgdat);
-
-out:
- unlock_system_sleep();
- return ret;
-}
-EXPORT_SYMBOL_GPL(xen_add_memory);
-#endif
-
-#ifdef CONFIG_XEN_MEMORY_HOTPLUG
-int xen_memory_probe(u64 phys_addr)
-{
- int nr_pages, ret;
- struct resource *r;
- struct xen_memory_reservation reservation = {
- .address_bits = 0,
- .extent_order = 0,
- .domid = DOMID_SELF,
- .nr_extents = PAGES_PER_SECTION
- };
- unsigned long *frame_list, i, pfn;
-
- r = register_memory_resource(phys_addr, PAGES_PER_SECTION << PAGE_SHIFT);
-
- if (!r)
- return -EEXIST;
-
- frame_list = vmalloc(PAGES_PER_SECTION * sizeof(unsigned long));
-
- if (!frame_list) {
- printk(KERN_ERR "%s: vmalloc: Out of memory\n", __func__);
- ret = -ENOMEM;
- goto error;
- }
-
- set_xen_guest_handle(reservation.extent_start, frame_list);
- for (i = 0, pfn = PFN_DOWN(phys_addr); i < PAGES_PER_SECTION; ++i, ++pfn)
- frame_list[i] = pfn;
-
- ret = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
-
- if (ret < PAGES_PER_SECTION) {
- if (ret > 0) {
- printk(KERN_ERR "%s: PHYSMAP is not fully "
- "populated: %i/%lu\n", __func__,
- ret, PAGES_PER_SECTION);
- reservation.nr_extents = nr_pages = ret;
- ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
- BUG_ON(ret != nr_pages);
- ret = -ENOMEM;
- } else {
- ret = (ret < 0) ? ret : -ENOMEM;
- printk(KERN_ERR "%s: Can't populate PHYSMAP: %i\n", __func__, ret);
- }
- goto error;
- }
-
- for (i = 0, pfn = PFN_DOWN(phys_addr); i < PAGES_PER_SECTION; ++i, ++pfn) {
- BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
- phys_to_machine_mapping_valid(pfn));
- set_phys_to_machine(pfn, frame_list[i]);
- }
-
- ret = xen_add_memory(memory_add_physaddr_to_nid(phys_addr), phys_addr,
- PAGES_PER_SECTION << PAGE_SHIFT);
-
- if (ret) {
- printk(KERN_ERR "%s: xen_add_memory: Memory hotplug "
- "failed: %i\n", __func__, ret);
- goto out;
- }
-
- for (i = 0, pfn = PFN_DOWN(phys_addr); i < PAGES_PER_SECTION; ++i, ++pfn)
- if (!PageHighMem(pfn_to_page(pfn)))
- BUG_ON(HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- mfn_pte(frame_list[i], PAGE_KERNEL), 0));
-
- goto out;
-
-error:
- release_memory_resource(r);
-
-out:
- vfree(frame_list);
-
- return (ret < 0) ? ret : 0;
-}
-EXPORT_SYMBOL_GPL(xen_memory_probe);
-#endif
-
#ifdef CONFIG_MEMORY_HOTREMOVE
/*
* A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
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