From e6eaa683bc403b5e0900af79ca241f8c1c87143e Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Wed, 7 Nov 2007 13:41:29 +0000 Subject: [PATCH] [SHADOW] Fix up change that allowed MMIO mappings to be shadowed so it doesn't let us map INVALID_MFN as a shadow pagetable page. Signed-off-by: Tim Deegan --- xen/arch/x86/mm/shadow/multi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c index a148b16a24..8eddd61538 100644 --- a/xen/arch/x86/mm/shadow/multi.c +++ b/xen/arch/x86/mm/shadow/multi.c @@ -716,12 +716,14 @@ _sh_propagate(struct vcpu *v, goto done; } - // Must have a valid target_mfn unless this is a prefetch. In the - // case of a prefetch, an invalid mfn means that we can not usefully - // shadow anything, and so we return early. + // Must have a valid target_mfn unless this is a prefetch or an l1 + // pointing at MMIO space. In the case of a prefetch, an invalid + // mfn means that we can not usefully shadow anything, and so we + // return early. // - if ( shadow_mode_refcounts(d) && - !mfn_valid(target_mfn) && (p2mt != p2m_mmio_direct) ) + if ( !mfn_valid(target_mfn) + && !(level == 1 && (!shadow_mode_refcounts(d) + || p2mt == p2m_mmio_direct)) ) { ASSERT((ft == ft_prefetch)); *sp = shadow_l1e_empty(); -- 2.30.2