From ddd3509df8f8d4f1cf4784f559d702ce00dc8846 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 16 Nov 2012 19:39:05 -0800 Subject: [PATCH] x86, mm: Add pointer about Xen mmu requirement for alloc_low_pages Add link for more information 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve -v2: updated to commets from hpa to include commit name. Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1353123563-3103-29-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin --- arch/x86/mm/init.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 02cea14c6d0c..cb4f8ba70ecc 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -25,6 +25,15 @@ unsigned long __meminitdata pgt_buf_top; static unsigned long min_pfn_mapped; +/* + * Pages returned are already directly mapped. + * + * Changing that is likely to break Xen, see commit: + * + * 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve + * + * for detailed information. + */ __ref void *alloc_low_pages(unsigned int num) { unsigned long pfn; -- 2.20.1