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Diffstat (limited to 'drivers/xen/balloon.c')
-rw-r--r--drivers/xen/balloon.c137
1 files changed, 78 insertions, 59 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index a50c6e3a7cc..5c660c77f03 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -157,13 +157,6 @@ static struct page *balloon_retrieve(bool prefer_highmem)
return page;
}
-static struct page *balloon_first_page(void)
-{
- if (list_empty(&ballooned_pages))
- return NULL;
- return list_entry(ballooned_pages.next, struct page, lru);
-}
-
static struct page *balloon_next_page(struct page *page)
{
struct list_head *next = page->lru.next;
@@ -328,7 +321,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
- page = balloon_first_page();
+ page = list_first_entry_or_null(&ballooned_pages, struct page, lru);
for (i = 0; i < nr_pages; i++) {
if (!page) {
nr_pages = i;
@@ -350,17 +343,19 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
pfn = page_to_pfn(page);
- set_phys_to_machine(pfn, frame_list[i]);
-
#ifdef CONFIG_XEN_HAVE_PVMMU
- /* Link back into the page tables if not highmem. */
- if (xen_pv_domain() && !PageHighMem(page)) {
- int ret;
- ret = HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- mfn_pte(frame_list[i], PAGE_KERNEL),
- 0);
- BUG_ON(ret);
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ set_phys_to_machine(pfn, frame_list[i]);
+
+ /* Link back into the page tables if not highmem. */
+ if (!PageHighMem(page)) {
+ int ret;
+ ret = HYPERVISOR_update_va_mapping(
+ (unsigned long)__va(pfn << PAGE_SHIFT),
+ mfn_pte(frame_list[i], PAGE_KERNEL),
+ 0);
+ BUG_ON(ret);
+ }
}
#endif
@@ -378,7 +373,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
enum bp_state state = BP_DONE;
unsigned long pfn, i;
struct page *page;
- struct page *scratch_page;
int ret;
struct xen_memory_reservation reservation = {
.address_bits = 0,
@@ -398,8 +392,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
- scratch_page = get_balloon_scratch_page();
-
for (i = 0; i < nr_pages; i++) {
page = alloc_page(gfp);
if (page == NULL) {
@@ -407,39 +399,52 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
state = BP_EAGAIN;
break;
}
-
- pfn = page_to_pfn(page);
- frame_list[i] = pfn_to_mfn(pfn);
-
scrub_page(page);
-#ifdef CONFIG_XEN_HAVE_PVMMU
- if (xen_pv_domain() && !PageHighMem(page)) {
- ret = HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- pfn_pte(page_to_pfn(scratch_page),
- PAGE_KERNEL_RO), 0);
- BUG_ON(ret);
- }
-#endif
+ frame_list[i] = page_to_pfn(page);
}
- /* Ensure that ballooned highmem pages don't have kmaps. */
+ /*
+ * Ensure that ballooned highmem pages don't have kmaps.
+ *
+ * Do this before changing the p2m as kmap_flush_unused()
+ * reads PTEs to obtain pages (and hence needs the original
+ * p2m entry).
+ */
kmap_flush_unused();
- flush_tlb_all();
- /* No more mappings: invalidate P2M and add to balloon. */
+ /* Update direct mapping, invalidate P2M, and add to balloon. */
for (i = 0; i < nr_pages; i++) {
- pfn = mfn_to_pfn(frame_list[i]);
+ pfn = frame_list[i];
+ frame_list[i] = pfn_to_mfn(pfn);
+ page = pfn_to_page(pfn);
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+ /*
+ * Ballooned out frames are effectively replaced with
+ * a scratch frame. Ensure direct mappings and the
+ * p2m are consistent.
+ */
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
- unsigned long p;
- p = page_to_pfn(scratch_page);
- __set_phys_to_machine(pfn, pfn_to_mfn(p));
+ if (!PageHighMem(page)) {
+ struct page *scratch_page = get_balloon_scratch_page();
+
+ ret = HYPERVISOR_update_va_mapping(
+ (unsigned long)__va(pfn << PAGE_SHIFT),
+ pfn_pte(page_to_pfn(scratch_page),
+ PAGE_KERNEL_RO), 0);
+ BUG_ON(ret);
+
+ put_balloon_scratch_page();
+ }
+ __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
- balloon_append(pfn_to_page(pfn));
+#endif
+
+ balloon_append(page);
}
- put_balloon_scratch_page();
+ flush_tlb_all();
set_xen_guest_handle(reservation.extent_start, frame_list);
reservation.nr_extents = nr_pages;
@@ -597,19 +602,29 @@ static void __init balloon_add_region(unsigned long start_pfn,
}
}
-static int __cpuinit balloon_cpu_notify(struct notifier_block *self,
+static int alloc_balloon_scratch_page(int cpu)
+{
+ if (per_cpu(balloon_scratch_page, cpu) != NULL)
+ return 0;
+
+ per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL);
+ if (per_cpu(balloon_scratch_page, cpu) == NULL) {
+ pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+
+static int balloon_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
int cpu = (long)hcpu;
switch (action) {
case CPU_UP_PREPARE:
- if (per_cpu(balloon_scratch_page, cpu) != NULL)
- break;
- per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL);
- if (per_cpu(balloon_scratch_page, cpu) == NULL) {
- pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu);
+ if (alloc_balloon_scratch_page(cpu))
return NOTIFY_BAD;
- }
break;
default:
break;
@@ -617,7 +632,7 @@ static int __cpuinit balloon_cpu_notify(struct notifier_block *self,
return NOTIFY_OK;
}
-static struct notifier_block balloon_cpu_notifier __cpuinitdata = {
+static struct notifier_block balloon_cpu_notifier = {
.notifier_call = balloon_cpu_notify,
};
@@ -628,21 +643,25 @@ static int __init balloon_init(void)
if (!xen_domain())
return -ENODEV;
- for_each_online_cpu(cpu)
- {
- per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL);
- if (per_cpu(balloon_scratch_page, cpu) == NULL) {
- pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu);
- return -ENOMEM;
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ register_cpu_notifier(&balloon_cpu_notifier);
+
+ get_online_cpus();
+ for_each_online_cpu(cpu) {
+ if (alloc_balloon_scratch_page(cpu)) {
+ put_online_cpus();
+ unregister_cpu_notifier(&balloon_cpu_notifier);
+ return -ENOMEM;
+ }
}
+ put_online_cpus();
}
- register_cpu_notifier(&balloon_cpu_notifier);
pr_info("Initialising balloon driver\n");
balloon_stats.current_pages = xen_pv_domain()
? min(xen_start_info->nr_pages - xen_released_pages, max_pfn)
- : max_pfn;
+ : get_num_physpages();
balloon_stats.target_pages = balloon_stats.current_pages;
balloon_stats.balloon_low = 0;
balloon_stats.balloon_high = 0;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 11:14:36 +0000