This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] [PATCH] xen/p2m: Allocate p2m tracking pages on override

To: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Subject: [Xen-devel] [PATCH] xen/p2m: Allocate p2m tracking pages on override
From: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
Date: Thu, 24 Mar 2011 08:10:07 -0400
Cc: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 24 Mar 2011 05:12:26 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
It is possible to add a p2m override on pages that are currently mapped
to INVALID_P2M_ENTRY; in particular, this will happen when using
ballooned pages in gntdev. This means that set_phys_to_machine must be
used instead of __set_phys_to_machine.

Signed-off-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
 arch/x86/xen/p2m.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index b02b117..7ff3a9e 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -670,7 +670,9 @@ int m2p_add_override(unsigned long mfn, struct page *page, 
bool clear_pte)
        page->private = mfn;
        page->index = pfn_to_mfn(pfn);
-       __set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
+       if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
+               return -ENOMEM;
        if (clear_pte && !PageHighMem(page))
                /* Just zap old mapping for now */
                pte_clear(&init_mm, address, ptep);
@@ -707,7 +709,7 @@ int m2p_remove_override(struct page *page, bool clear_pte)
        spin_lock_irqsave(&m2p_override_lock, flags);
        spin_unlock_irqrestore(&m2p_override_lock, flags);
-       __set_phys_to_machine(pfn, page->index);
+       set_phys_to_machine(pfn, page->index);
        if (clear_pte && !PageHighMem(page))
                set_pte_at(&init_mm, address, ptep,

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-devel] [PATCH] xen/p2m: Allocate p2m tracking pages on override, Daniel De Graaf <=