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-rw-r--r--arch/x86/xen/enlighten.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index d669e9d89001..c9081c6671f0 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1,8 +1,12 @@
+#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
+#include <linux/bootmem.h>
+#endif
#include <linux/cpu.h>
#include <linux/kexec.h>
#include <xen/features.h>
#include <xen/page.h>
+#include <xen/interface/memory.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
@@ -331,3 +335,80 @@ void xen_arch_unregister_cpu(int num)
}
EXPORT_SYMBOL(xen_arch_unregister_cpu);
#endif
+
+#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
+void __init arch_xen_balloon_init(struct resource *hostmem_resource)
+{
+ struct xen_memory_map memmap;
+ int rc;
+ unsigned int i, last_guest_ram;
+ phys_addr_t max_addr = PFN_PHYS(max_pfn);
+ struct e820_table *xen_e820_table;
+ const struct e820_entry *entry;
+ struct resource *res;
+
+ if (!xen_initial_domain())
+ return;
+
+ xen_e820_table = kmalloc(sizeof(*xen_e820_table), GFP_KERNEL);
+ if (!xen_e820_table)
+ return;
+
+ memmap.nr_entries = ARRAY_SIZE(xen_e820_table->entries);
+ set_xen_guest_handle(memmap.buffer, xen_e820_table->entries);
+ rc = HYPERVISOR_memory_op(XENMEM_machine_memory_map, &memmap);
+ if (rc) {
+ pr_warn("%s: Can't read host e820 (%d)\n", __func__, rc);
+ goto out;
+ }
+
+ last_guest_ram = 0;
+ for (i = 0; i < memmap.nr_entries; i++) {
+ if (xen_e820_table->entries[i].addr >= max_addr)
+ break;
+ if (xen_e820_table->entries[i].type == E820_TYPE_RAM)
+ last_guest_ram = i;
+ }
+
+ entry = &xen_e820_table->entries[last_guest_ram];
+ if (max_addr >= entry->addr + entry->size)
+ goto out; /* No unallocated host RAM. */
+
+ hostmem_resource->start = max_addr;
+ hostmem_resource->end = entry->addr + entry->size;
+
+ /*
+ * Mark non-RAM regions between the end of dom0 RAM and end of host RAM
+ * as unavailable. The rest of that region can be used for hotplug-based
+ * ballooning.
+ */
+ for (; i < memmap.nr_entries; i++) {
+ entry = &xen_e820_table->entries[i];
+
+ if (entry->type == E820_TYPE_RAM)
+ continue;
+
+ if (entry->addr >= hostmem_resource->end)
+ break;
+
+ res = kzalloc(sizeof(*res), GFP_KERNEL);
+ if (!res)
+ goto out;
+
+ res->name = "Unavailable host RAM";
+ res->start = entry->addr;
+ res->end = (entry->addr + entry->size < hostmem_resource->end) ?
+ entry->addr + entry->size : hostmem_resource->end;
+ rc = insert_resource(hostmem_resource, res);
+ if (rc) {
+ pr_warn("%s: Can't insert [%llx - %llx) (%d)\n",
+ __func__, res->start, res->end, rc);
+ kfree(res);
+ goto out;
+ }
+ }
+
+ out:
+ kfree(xen_e820_table);
+}
+#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */