[Xen-devel] [PATCH 06/10] Xen: Add memory hotadd to pvops dom0

["Liu, Jinsong" <jinsong.liu@xxxxxxxxx>]

>From a5d21e2a01049eef6aa64406e71f6574e7a371c1 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@xxxxxxxxx>
Date: Sun, 11 Dec 2011 21:51:28 +0800
Subject: [PATCH 06/10] Xen: Add memory hotadd to pvops dom0

This patch rebased from Jeremy's pvops commit
fe3cb1ebf78399fd5176ff6aa1c9ab498f2d8bd7

When memory hotadd event happen, a Xen hook will be called, to notify
hypervisor of the new added memory.

Because xen hypervisor will use the new memory to setup frametable/m2p
table, so dom0 will always return success to acpi bios, and notify xen
hypervisor later.

It add a hook in driver/acpi/acpi_memhotplug.c, but that change is
quite small, not sure if it is acceptable. Other method is to provide
a xen specific acpi_memory_device_driver, but I'm not sure if it worth
to add so much changes, to simply avoid two hooks.

Signed-off-by: Liu, Jinsong <jinsong.liu@xxxxxxxxx>
Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 drivers/acpi/acpi_memhotplug.c    |    4 +
 drivers/xen/Makefile              |    1 +
 drivers/xen/xen_acpi_memhotplug.c |  209 +++++++++++++++++++++++++++++++++++++
 include/xen/acpi.h                |    5 +
 include/xen/interface/platform.h  |    9 ++
 5 files changed, 228 insertions(+), 0 deletions(-)
 create mode 100644 drivers/xen/xen_acpi_memhotplug.c

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e28e64d..2f2169e 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -32,6 +32,7 @@
 #include <linux/memory_hotplug.h>
 #include <linux/slab.h>
 #include <acpi/acpi_drivers.h>
+#include <xen/acpi.h>
 
 #define ACPI_MEMORY_DEVICE_CLASS               "memory"
 #define ACPI_MEMORY_DEVICE_HID                 "PNP0C80"
@@ -214,6 +215,9 @@ static int acpi_memory_enable_device(struct 
acpi_memory_device *mem_device)
                return result;
        }
 
+       if (xen_initial_domain())
+               return xen_hotadd_memory(mem_device);
+
        node = acpi_get_node(mem_device->device->handle);
        /*
         * Tell the VM there is more memory here...
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index aedaf48..7dc3c0b 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_XEN_TMEM)                        += tmem.o
 obj-$(CONFIG_SWIOTLB_XEN)              += swiotlb-xen.o
 obj-$(CONFIG_XEN_DOM0)                 += pci.o acpi.o
 obj-$(CONFIG_XEN_PCIDEV_BACKEND)       += xen-pciback/
+obj-$(CONFIG_ACPI_HOTPLUG_MEMORY)      += xen_acpi_memhotplug.o
 ifdef CONFIG_ACPI_PROCESSOR_XEN
 obj-$(CONFIG_ACPI_PROCESSOR)           += acpi_processor.o
 endif
diff --git a/drivers/xen/xen_acpi_memhotplug.c 
b/drivers/xen/xen_acpi_memhotplug.c
new file mode 100644
index 0000000..0c4af99
--- /dev/null
+++ b/drivers/xen/xen_acpi_memhotplug.c
@@ -0,0 +1,209 @@
+/*
+ *  xen_acpi_memhotplug.c - interface to notify Xen on memory device hotadd
+ *
+ *  Copyright (C) 2008, Intel corporation
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/memory_hotplug.h>
+#include <acpi/acpi_drivers.h>
+#include <xen/interface/platform.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+#include <xen/acpi.h>
+
+struct xen_hotmem_entry {
+       struct list_head hotmem_list;
+       uint64_t start;
+       uint64_t end;
+       uint32_t flags;
+       uint32_t pxm;
+};
+
+struct xen_hotmem_list {
+       struct list_head list;
+       int entry_nr;
+} xen_hotmem;
+
+DEFINE_SPINLOCK(xen_hotmem_lock);
+
+static int xen_hyper_addmem(struct xen_hotmem_entry *entry)
+{
+       int ret;
+
+       xen_platform_op_t op = {
+               .cmd            = XENPF_mem_hotadd,
+               .interface_version  = XENPF_INTERFACE_VERSION,
+       };
+       op.u.mem_add.spfn = entry->start >> PAGE_SHIFT;
+       op.u.mem_add.epfn = entry->end >> PAGE_SHIFT;
+       op.u.mem_add.flags = entry->flags;
+       op.u.mem_add.pxm = entry->pxm;
+
+       ret = HYPERVISOR_dom0_op(&op);
+       return ret;
+}
+
+static int add_hotmem_entry(int pxm, uint64_t start,
+                       uint64_t length, uint32_t flags)
+{
+       struct xen_hotmem_entry *entry;
+
+       if (pxm < 0 || !length)
+               return -EINVAL;
+
+       entry = kzalloc(sizeof(struct xen_hotmem_entry), GFP_ATOMIC);
+       if (!entry)
+               return -ENOMEM;
+
+       INIT_LIST_HEAD(&entry->hotmem_list);
+       entry->start = start;
+       entry->end = start + length;
+       entry->flags = flags;
+       entry->pxm = pxm;
+
+       spin_lock(&xen_hotmem_lock);
+
+       list_add_tail(&entry->hotmem_list, &xen_hotmem.list);
+       xen_hotmem.entry_nr++;
+
+       spin_unlock(&xen_hotmem_lock);
+
+       return 0;
+}
+
+static int free_hotmem_entry(struct xen_hotmem_entry *entry)
+{
+       list_del(&entry->hotmem_list);
+       kfree(entry);
+
+       return 0;
+}
+
+static void xen_hotadd_mem_dpc(struct work_struct *work)
+{
+       struct list_head *elem, *tmp;
+       struct xen_hotmem_entry *entry;
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&xen_hotmem_lock, flags);
+       list_for_each_safe(elem, tmp, &xen_hotmem.list) {
+               entry = list_entry(elem, struct xen_hotmem_entry, hotmem_list);
+               ret = xen_hyper_addmem(entry);
+               if (ret)
+                       printk(KERN_WARNING "xen addmem failed with %x\n", ret);
+               free_hotmem_entry(entry);
+               xen_hotmem.entry_nr--;
+       }
+       spin_unlock_irqrestore(&xen_hotmem_lock, flags);
+}
+
+static DECLARE_WORK(xen_hotadd_mem_work, xen_hotadd_mem_dpc);
+
+static int xen_acpi_get_pxm(acpi_handle h)
+{
+       unsigned long long pxm;
+       acpi_status status;
+       acpi_handle handle;
+       acpi_handle phandle = h;
+
+       do {
+               handle = phandle;
+               status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
+               if (ACPI_SUCCESS(status))
+                       return pxm;
+               status = acpi_get_parent(handle, &phandle);
+       } while (ACPI_SUCCESS(status));
+
+       return -1;
+}
+
+int xen_hotadd_memory(struct acpi_memory_device *mem_device)
+{
+       int pxm, result;
+       int num_enabled = 0;
+       struct acpi_memory_info *info;
+
+       if (!mem_device)
+               return -EINVAL;
+
+       pxm = xen_acpi_get_pxm(mem_device->device->handle);
+
+       if (pxm < 0)
+               return -EINVAL;
+
+       /*
+        * Always return success to ACPI driver, and notify hypervisor later
+        * because hypervisor will utilize the memory in memory hotadd hypercall
+        */
+       list_for_each_entry(info, &mem_device->res_list, list) {
+               if (info->enabled) { /* just sanity check...*/
+                       num_enabled++;
+                       continue;
+               }
+               /*
+                * If the memory block size is zero, please ignore it.
+                * Don't try to do the following memory hotplug flowchart.
+                */
+               if (!info->length)
+                       continue;
+
+               result = add_hotmem_entry(pxm, info->start_addr,
+                                       info->length, 0);
+               if (result)
+                       continue;
+               info->enabled = 1;
+               num_enabled++;
+       }
+
+       if (!num_enabled)
+               return -EINVAL;
+
+       schedule_work(&xen_hotadd_mem_work);
+
+       return 0;
+}
+EXPORT_SYMBOL(xen_hotadd_memory);
+
+static int xen_hotadd_mem_init(void)
+{
+       if (!xen_initial_domain())
+               return -ENODEV;
+
+       INIT_LIST_HEAD(&xen_hotmem.list);
+       xen_hotmem.entry_nr = 0;
+
+       return 0;
+}
+
+static void xen_hotadd_mem_exit(void)
+{
+       flush_scheduled_work();
+}
+
+module_init(xen_hotadd_mem_init);
+module_exit(xen_hotadd_mem_exit);
+MODULE_LICENSE("GPL");
diff --git a/include/xen/acpi.h b/include/xen/acpi.h
index 7aa282d..8b3462e 100644
--- a/include/xen/acpi.h
+++ b/include/xen/acpi.h
@@ -107,6 +107,11 @@ static inline int 
xen_acpi_processor_get_performance(struct acpi_processor *pr)
 }
 #endif
 
+#if defined(CONFIG_ACPI_HOTPLUG_MEMORY) || \
+defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)
+int xen_hotadd_memory(struct acpi_memory_device *mem_device);
+#endif
+
 #if defined(CONFIG_ACPI_PROCESSOR_XEN) || \
 defined(CONFIG_ACPI_PROCESSOR_XEN_MODULE)
 
diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h
index 9fd6b07..0787c68 100644
--- a/include/xen/interface/platform.h
+++ b/include/xen/interface/platform.h
@@ -329,6 +329,14 @@ struct xenpf_cpu_hotadd {
        uint32_t pxm;
 };
 
+#define XENPF_mem_hotadd    59
+struct xenpf_mem_hotadd {
+       uint64_t spfn;
+       uint64_t epfn;
+       uint32_t pxm;
+       uint32_t flags;
+};
+
 struct xen_platform_op {
        uint32_t cmd;
        uint32_t interface_version; /* XENPF_INTERFACE_VERSION */
@@ -347,6 +355,7 @@ struct xen_platform_op {
                struct xenpf_pcpuinfo          pcpu_info;
                struct xenpf_cpu_ol            cpu_ol;
                struct xenpf_cpu_hotadd        cpu_add;
+               struct xenpf_mem_hotadd        mem_add;
                uint8_t                        pad[128];
        } u;
 };
-- 
1.6.5.6

Attachment: 0006-Xen-Add-memory-hotadd-to-pvops-dom0.patch
Description: 0006-Xen-Add-memory-hotadd-to-pvops-dom0.patch

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