WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH] GSoC 2010 - Memory hotplug support for Xen guests -

To: jeremy@xxxxxxxx, konrad.wilk@xxxxxxxxxx, stefano.stabellini@xxxxxxxxxxxxx, linux-mm@xxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, v.tolstov@xxxxxxxxx
Subject: [Xen-devel] [PATCH] GSoC 2010 - Memory hotplug support for Xen guests - second fully working version
From: Daniel Kiper <dkiper@xxxxxxxxxxxx>
Date: Mon, 2 Aug 2010 00:00:49 +0200
Cc:
Delivery-date: Sun, 01 Aug 2010 15:03:53 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.3.28i
Hi,

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@xxxxxxxxxxxx>
---
 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

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-devel] [PATCH] GSoC 2010 - Memory hotplug support for Xen guests - second fully working version, Daniel Kiper <=