Commit cf04d120 authored by Stefan Bader's avatar Stefan Bader Committed by Konrad Rzeszutek Wilk
Browse files

xen/p2m: Mark INVALID_P2M_ENTRY the mfn_list past max_pfn. 



In case the mfn_list does not have enough entries to fill
a p2m page we do not want the entries from max_pfn up to
the boundary to be filled with unknown values. Hence
set them to INVALID_P2M_ENTRY.

Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 1bae4ce2

arch/x86/xen/p2m.c

+6 −12
Original line number Diff line number Diff line
@@ -241,20 +241,14 @@ void __init xen_build_dynamic_phys_to_machine(void) 
		 * As long as the mfn_list has enough entries to completely

		 * fill a p2m page, pointing into the array is ok. But if

		 * not the entries beyond the last pfn will be undefined.

		 * And guessing that the 'what-ever-there-is' does not take it

		 * too kindly when changing it to invalid markers, a new page

		 * is allocated, initialized and filled with the valid part.

		 */

		if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) {

			unsigned long p2midx;

			unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);

			p2m_init(p2m);



			for (p2midx = 0; pfn + p2midx < max_pfn; p2midx++) {

				p2m[p2midx] = mfn_list[pfn + p2midx];

			p2midx = max_pfn % P2M_PER_PAGE;

			for ( ; p2midx < P2M_PER_PAGE; p2midx++)

				mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY;

		}

			p2m_top[topidx][mididx] = p2m;

		} else

		p2m_top[topidx][mididx] = &mfn_list[pfn];

	}

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