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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-12-11 16:58:42 +0000
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-12-13 11:20:30 -0500
commitc1d15f5c8bc1170dafe16e988e55437245966dfe (patch)
treebb1c364882addcaa8ac053ed12ae7a501f54a3be /drivers/xen
parent380108d891acf8db5cf0d477176c7ed2b62b7928 (diff)
xen/balloon: Seperate the auto-translate logic properly (v2)
The auto-xlat logic vs the non-xlat means that we don't need to for auto-xlat guests (like PVH, HVM or ARM): - use P2M - use scratch page. However the code in increase_reservation does modify the p2m for auto_translate guests, but not in decrease_reservation. Fix that by avoiding any p2m modifications in both increase_reservation and decrease_reservation for auto_translated guests. And also avoid allocating or using scratch pages for auto_translated guests. Lastly, since !auto-xlat is really another way of saying 'xen_pv' remove the redundant 'xen_pv_domain' check. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v2: Updated the description] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/balloon.c63
1 files changed, 34 insertions, 29 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 55ea73f7c70b..4c02e2b94103 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -350,17 +350,19 @@ 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 +380,6 @@ 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,
@@ -411,27 +412,29 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
scrub_page(page);
+#ifdef CONFIG_XEN_HAVE_PVMMU
/*
* Ballooned out frames are effectively replaced with
* a scratch frame. Ensure direct mappings and the
* p2m are consistent.
*/
- scratch_page = get_balloon_scratch_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
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
unsigned long p;
+ struct page *scratch_page = get_balloon_scratch_page();
+
+ if (!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);
+ }
p = page_to_pfn(scratch_page);
__set_phys_to_machine(pfn, pfn_to_mfn(p));
+
+ put_balloon_scratch_page();
}
- put_balloon_scratch_page();
+#endif
balloon_append(pfn_to_page(pfn));
}
@@ -627,15 +630,17 @@ 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)) {
+ 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;
+ }
}
+ register_cpu_notifier(&balloon_cpu_notifier);
}
- register_cpu_notifier(&balloon_cpu_notifier);
pr_info("Initialising balloon driver\n");