On 12/15/2010 05:40 AM, stefano.stabellini@xxxxxxxxxxxxx wrote:
> From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
>
> In m2p_add_override store the original mfn into page->index and then
> change the p2m mapping, setting mfns as FOREIGN_FRAME.
>
> In m2p_remove_override restore the original mapping.
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> ---
> arch/x86/xen/p2m.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
> index 8db19d5..7dde8e4 100644
> --- a/arch/x86/xen/p2m.c
> +++ b/arch/x86/xen/p2m.c
> @@ -407,8 +407,11 @@ static unsigned long mfn_hash(unsigned long mfn)
> void m2p_add_override(unsigned long mfn, struct page *page)
> {
> unsigned long flags;
> + unsigned long pfn = page_to_pfn(page);
> page->private = mfn;
> + page->index = pfn_to_mfn(pfn);
Is there any risk that a page being used for a granted mfn will end up
getting xen_create_contiguous_region() applied to it via the DMA API?
That would be messy...
J
>
> + __set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
> spin_lock_irqsave(&m2p_override_lock, flags);
> list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
> spin_unlock_irqrestore(&m2p_override_lock, flags);
> @@ -420,6 +423,7 @@ void m2p_remove_override(struct page *page)
> spin_lock_irqsave(&m2p_override_lock, flags);
> list_del(&page->lru);
> spin_unlock_irqrestore(&m2p_override_lock, flags);
> + __set_phys_to_machine(page_to_pfn(page), page->index);
> }
>
> struct page *m2p_find_override(unsigned long mfn)
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home