From: Julien Grall <julien.grall@citrix.com>
To: xen-devel@lists.xenproject.org
Cc: Wei Liu <wei.liu2@citrix.com>,
ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com,
linux-kernel@vger.kernel.org,
Julien Grall <julien.grall@citrix.com>,
David Vrabel <david.vrabel@citrix.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 12/20] xen/balloon: Don't rely on the page granularity is the same for Xen and Linux
Date: Mon, 7 Sep 2015 16:33:50 +0100 [thread overview]
Message-ID: <1441640038-23615-13-git-send-email-julien.grall__47999.1969107234$1441640403$gmane$org@citrix.com> (raw)
In-Reply-To: <1441640038-23615-1-git-send-email-julien.grall@citrix.com>
For ARM64 guests, Linux is able to support either 64K or 4K page
granularity. Although, the hypercall interface is always based on 4K
page granularity.
With 64K page granularity, a single page will be spread over multiple
Xen frame.
To avoid splitting the page into 4K frame, take advantage of the
extent_order field to directly allocate/free chunk of the Linux page
size.
Note that PVMMU is only used for PV guest (which is x86) and the page
granularity is always 4KB. Some BUILD_BUG_ON has been added to ensure
that because the code has not been modified.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
---
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Note that two BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE) in code built
for the PV MMU code is kept in order to have at least one even if we
ever decide to drop of code section.
Changes in v4:
- s/xen_page_to_pfn/page_to_xen_pfn/ based on the new naming
- Use the field lru in the page to get a list of pages when
decreasing the memory reservation. It avoids to use a static
array to store the pages (see v3).
- Update comment for EXTENT_ORDER.
Changes in v3:
- Fix errors reported by checkpatch.pl
- s/mfn/gfn/ based on the new naming
- Rather than splitting the page into 4KB chunk, use the
extent_order field to allocate directly a Linux page size. This
is avoid lots of code for no benefits.
Changes in v2:
- Use xen_apply_to_page to split a page in 4K chunk
- It's not necessary to have a smaller frame list. Re-use
PAGE_SIZE
- Convert reserve_additional_memory to use XEN_... macro
---
drivers/xen/balloon.c | 59 ++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 44 insertions(+), 15 deletions(-)
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index c79329f..3babf13 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -70,6 +70,11 @@
#include <xen/features.h>
#include <xen/page.h>
+/* Use one extent per PAGE_SIZE to avoid to break down the page into
+ * multiple frame.
+ */
+#define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1)
+
/*
* balloon_process() state:
*
@@ -230,6 +235,11 @@ static enum bp_state reserve_additional_memory(long credit)
nid = memory_add_physaddr_to_nid(hotplug_start_paddr);
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /* We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
/*
* add_memory() will build page tables for the new memory so
* the p2m must contain invalid entries so the correct
@@ -326,11 +336,11 @@ static enum bp_state reserve_additional_memory(long credit)
static enum bp_state increase_reservation(unsigned long nr_pages)
{
int rc;
- unsigned long pfn, i;
+ unsigned long i;
struct page *page;
struct xen_memory_reservation reservation = {
.address_bits = 0,
- .extent_order = 0,
+ .extent_order = EXTENT_ORDER,
.domid = DOMID_SELF
};
@@ -352,7 +362,11 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
nr_pages = i;
break;
}
- frame_list[i] = page_to_pfn(page);
+
+ /* XENMEM_populate_physmap requires a PFN based on Xen
+ * granularity.
+ */
+ frame_list[i] = page_to_xen_pfn(page);
page = balloon_next_page(page);
}
@@ -366,10 +380,15 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
page = balloon_retrieve(false);
BUG_ON(page == NULL);
- pfn = page_to_pfn(page);
-
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /* We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ unsigned long pfn = page_to_pfn(page);
+
set_phys_to_machine(pfn, frame_list[i]);
/* Link back into the page tables if not highmem. */
@@ -396,14 +415,15 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
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;
+ unsigned long i;
+ struct page *page, *tmp;
int ret;
struct xen_memory_reservation reservation = {
.address_bits = 0,
- .extent_order = 0,
+ .extent_order = EXTENT_ORDER,
.domid = DOMID_SELF
};
+ LIST_HEAD(pages);
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
if (balloon_stats.hotplug_pages) {
@@ -425,8 +445,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
break;
}
scrub_page(page);
-
- frame_list[i] = page_to_pfn(page);
+ list_add(&page->lru, &pages);
}
/*
@@ -438,14 +457,23 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
*/
kmap_flush_unused();
- /* Update direct mapping, invalidate P2M, and add to balloon. */
- for (i = 0; i < nr_pages; i++) {
- pfn = frame_list[i];
- frame_list[i] = pfn_to_gfn(pfn);
- page = pfn_to_page(pfn);
+ /*
+ * Setup the frame, update direct mapping, invalidate P2M,
+ * and add to balloon.
+ */
+ list_for_each_entry_safe(page, tmp, &pages, lru) {
+ /* XENMEM_decrease_reservation requires a GFN */
+ frame_list[i] = xen_page_to_gfn(page);
#ifdef CONFIG_XEN_HAVE_PVMMU
+ /* We don't support PV MMU when Linux and Xen is using
+ * different page granularity.
+ */
+ BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
+
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ unsigned long pfn = page_to_pfn(page);
+
if (!PageHighMem(page)) {
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
@@ -455,6 +483,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
#endif
+ list_del(&page->lru);
balloon_append(page);
}
--
2.1.4
next prev parent reply other threads:[~2015-09-07 15:38 UTC|newest]
Thread overview: 143+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-07 15:33 [PATCH v4 00/20] xen/arm64: Add support for 64KB page in Linux Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 01/20] net/xen-netback: xenvif_gop_frag_copy: move GSO check out of the loop Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 02/20] arm/xen: Drop pte_mfn and mfn_pte Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 03/20] xen: Add Xen specific page definition Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 04/20] xen/grant: Introduce helpers to split a page into grant Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 05/20] xen/grant: Add helper gnttab_page_grant_foreign_access_ref_one Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 06/20] block/xen-blkfront: Split blkif_queue_request in 2 Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 07/20] block/xen-blkfront: Store a page rather a pfn in the grant structure Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 08/20] block/xen-blkfront: split get_grant in 2 Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 09/20] xen/biomerge: Don't allow biovec's to be merged when Linux is not using 4KB pages Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 10/20] xen/xenbus: Use Xen page definition Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 11/20] tty/hvc: xen: Use xen " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 12/20] xen/balloon: Don't rely on the page granularity is the same for Xen and Linux Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 16:39 ` Stefano Stabellini
2015-09-07 16:39 ` Stefano Stabellini
2015-09-07 16:39 ` Stefano Stabellini
2015-09-07 15:33 ` Julien Grall [this message]
2015-09-07 15:33 ` [PATCH v4 13/20] xen/events: fifo: Make it running on 64KB granularity Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 14/20] xen/grant-table: " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 15/20] block/xen-blkfront: Make it running on 64KB page granularity Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 16/20] block/xen-blkback: " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 17/20] net/xen-netfront: " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 18/20] net/xen-netback: " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 16:57 ` Wei Liu
2015-09-07 16:57 ` Wei Liu
2015-09-08 11:07 ` [Xen-devel] " Julien Grall
2015-09-08 11:07 ` Julien Grall
2015-09-08 11:09 ` Wei Liu
2015-09-08 11:09 ` [Xen-devel] " Wei Liu
2015-09-08 11:09 ` Wei Liu
2015-09-08 11:07 ` Julien Grall
2015-09-07 16:57 ` Wei Liu
2015-09-07 15:33 ` [PATCH v4 19/20] xen/privcmd: Add support for Linux " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` [PATCH v4 20/20] arm/xen: Add support for " Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-07 15:33 ` Julien Grall
2015-09-11 19:39 ` [Xen-devel] [PATCH v4 00/20] xen/arm64: Add support for 64KB page in Linux Julien Grall
2015-09-11 19:39 ` Julien Grall
2015-09-11 19:39 ` Julien Grall
2015-09-14 8:56 ` Roger Pau Monné
2015-09-14 8:56 ` Roger Pau Monné
2015-09-14 8:56 ` Roger Pau Monné
2015-09-14 10:40 ` Julien Grall
2015-09-14 10:40 ` Julien Grall
2015-09-14 11:04 ` Roger Pau Monné
2015-09-14 11:04 ` Roger Pau Monné
2015-09-14 11:04 ` Roger Pau Monné
2015-09-14 11:21 ` Julien Grall
2015-09-14 11:21 ` Julien Grall
2015-09-14 11:21 ` Julien Grall
2015-09-14 12:08 ` Roger Pau Monné
2015-09-14 12:08 ` Roger Pau Monné
2015-09-14 12:08 ` Roger Pau Monné
2015-09-14 12:47 ` Julien Grall
2015-09-14 12:47 ` Julien Grall
2015-09-14 12:47 ` Julien Grall
2015-09-14 14:29 ` Roger Pau Monné
2015-09-14 14:29 ` Roger Pau Monné
2015-09-14 14:29 ` Roger Pau Monné
2015-09-14 14:46 ` Julien Grall
2015-09-14 14:46 ` Julien Grall
2015-09-14 14:46 ` Julien Grall
2015-09-14 14:54 ` Stefano Stabellini
2015-09-14 14:54 ` Stefano Stabellini
2015-09-14 14:54 ` Stefano Stabellini
2015-09-14 15:23 ` Roger Pau Monné
2015-09-14 15:23 ` Roger Pau Monné
2015-09-22 10:59 ` Ian Campbell
2015-09-22 10:59 ` Ian Campbell
2015-10-06 9:28 ` Roger Pau Monné
2015-10-06 9:28 ` Roger Pau Monné
2015-10-06 10:17 ` Ian Campbell
2015-10-06 10:17 ` Ian Campbell
2015-10-06 10:17 ` Ian Campbell
2015-10-06 13:55 ` Stefano Stabellini
2015-10-06 13:55 ` Stefano Stabellini
2015-10-06 13:55 ` Stefano Stabellini
2015-10-06 9:28 ` Roger Pau Monné
2015-09-22 10:59 ` Ian Campbell
2015-09-14 15:23 ` Roger Pau Monné
2015-09-18 14:10 ` Julien Grall
2015-09-18 14:10 ` Julien Grall
2015-09-18 14:10 ` Julien Grall
2015-09-14 11:32 ` Arnd Bergmann
2015-09-14 11:32 ` Arnd Bergmann
2015-09-15 13:14 ` David Vrabel
2015-09-15 13:14 ` [Xen-devel] " David Vrabel
2015-09-15 13:14 ` David Vrabel
2015-09-15 13:24 ` Arnd Bergmann
2015-09-15 13:24 ` Arnd Bergmann
2015-09-15 13:24 ` Arnd Bergmann
2015-09-14 11:32 ` Arnd Bergmann
2015-09-14 10:40 ` Julien Grall
2015-09-29 16:27 ` [Xen-devel] " David Vrabel
2015-09-29 16:27 ` David Vrabel
2015-09-29 16:33 ` Julien Grall
2015-09-29 16:33 ` Julien Grall
2015-09-29 16:36 ` David Vrabel
2015-09-29 16:36 ` [Xen-devel] " David Vrabel
2015-09-29 16:36 ` David Vrabel
2015-09-29 16:33 ` Julien Grall
2015-09-29 16:27 ` David Vrabel
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