qubes-linux-kernel/patches.xen/balloon-0002-xen-balloon-Seperate-the-auto-translate-logic-proper.patch
2014-06-27 17:21:07 +02:00

146 lines
4.6 KiB
Diff

From c1d15f5c8bc1170dafe16e988e55437245966dfe Mon Sep 17 00:00:00 2001
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Date: Wed, 11 Dec 2013 16:58:42 +0000
Subject: [PATCH] xen/balloon: Seperate the auto-translate logic properly (v2)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Organization: Invisible Things Lab
Cc: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
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>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
drivers/xen/balloon.c | 63 +++++++++++++++++++++++++++------------------------
1 file changed, 34 insertions(+), 29 deletions(-)
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 55ea73f..4c02e2b 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)
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.
*/
- 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(page);
}
@@ -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");
--
1.8.1.4