Instead of placing hotplugged memory at the end of RAM (which may
conflict with PCI devices or reserved regions) use allocate_resource()
to get a new, suitably aligned resource that does not conflict.
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Reviewed-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
---
v3:
- Remove stale comment.
---
drivers/xen/balloon.c | 73 +++++++++++++++++++++++++++++++++++++--------------
1 file changed, 53 insertions(+), 20 deletions(-)
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index fd93369..7ecbbc5 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -54,6 +54,7 @@
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/percpu-defs.h>
+#include <linux/slab.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
@@ -208,26 +209,56 @@ static bool balloon_is_inflated(void)
return false;
}
-/*
- * reserve_additional_memory() adds memory region of size >= credit above
- * max_pfn. New region is section aligned and size is modified to be multiple
- * of section size. Those features allow optimal use of address space and
- * establish proper alignment when this function is called first time after
- * boot (last section not fully populated at boot time contains unused memory
- * pages with PG_reserved bit not set; online_pages_range() does not allow page
- * onlining in whole range if first onlined page does not have PG_reserved
- * bit set). Real size of added memory is established at page onlining stage.
- */
+static struct resource *additional_memory_resource(phys_addr_t size)
+{
+ struct resource *res;
+ int ret;
+
+ res = kzalloc(sizeof(*res), GFP_KERNEL);
+ if (!res)
+ return NULL;
+
+ res->name = "System RAM";
+ res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+ ret = allocate_resource(&iomem_resource, res,
+ size, 0, -1,
+ PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
+ if (ret < 0) {
+ pr_err("Cannot allocate new System RAM resource\n");
+ kfree(res);
+ return NULL;
+ }
+
+ return res;
+}
+
+static void release_memory_resource(struct resource *resource)
+{
+ if (!resource)
+ return;
+
+ /*
+ * No need to reset region to identity mapped since we now
+ * know that no I/O can be in this region
+ */
+ release_resource(resource);
+ kfree(resource);
+}
static enum bp_state reserve_additional_memory(long credit)
{
+ struct resource *resource;
int nid, rc;
- u64 hotplug_start_paddr;
- unsigned long balloon_hotplug = credit;
+ unsigned long balloon_hotplug;
+
+ balloon_hotplug = round_up(credit, PAGES_PER_SECTION);
+
+ resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE);
+ if (!resource)
+ goto err;
- hotplug_start_paddr = PFN_PHYS(SECTION_ALIGN_UP(max_pfn));
- balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION);
- nid = memory_add_physaddr_to_nid(hotplug_start_paddr);
+ nid = memory_add_physaddr_to_nid(resource->start);
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
@@ -242,21 +273,20 @@ static enum bp_state reserve_additional_memory(long credit)
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
unsigned long pfn, i;
- pfn = PFN_DOWN(hotplug_start_paddr);
+ pfn = PFN_DOWN(resource->start);
for (i = 0; i < balloon_hotplug; i++) {
if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
pr_warn("set_phys_to_machine() failed, no memory added\n");
- return BP_ECANCELED;
+ goto err;
}
}
}
#endif
- rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT);
-
+ rc = add_memory_resource(nid, resource);
if (rc) {
pr_warn("Cannot add additional memory (%i)\n", rc);
- return BP_ECANCELED;
+ goto err;
}
balloon_hotplug -= credit;
@@ -265,6 +295,9 @@ static enum bp_state reserve_additional_memory(long credit)
balloon_stats.balloon_hotplug = balloon_hotplug;
return BP_DONE;
+ err:
+ release_memory_resource(resource);
+ return BP_ECANCELED;
}
static void xen_online_page(struct page *page)
--
2.1.4
--
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