Message ID | 888b8f2b-4368-6179-25c5-dc3eb6acbf3d@suse.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | x86/shadow: correct GFN use by sh_unshadow_for_p2m_change() | expand |
At 16:42 +0100 on 28 Oct (1603903365), Jan Beulich wrote: > Luckily sh_remove_all_mappings()'s use of the parameter is limited to > generation of log messages. Nevertheless we'd better pass correct GFNs > around: > - the incoming GFN, when replacing a large page, may not be large page > aligned, > - incrementing by page-size-scaled values can't be right. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Tim Deegan <tim@xen.org> Thanks! Tim.
--- a/xen/arch/x86/mm/shadow/common.c +++ b/xen/arch/x86/mm/shadow/common.c @@ -3115,6 +3115,8 @@ static void sh_unshadow_for_p2m_change(s && mfn_valid(nmfn) ) npte = map_domain_page(nmfn); + gfn &= ~(L1_PAGETABLE_ENTRIES - 1); + for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) { if ( !npte @@ -3123,8 +3125,7 @@ static void sh_unshadow_for_p2m_change(s { /* This GFN->MFN mapping has gone away */ sh_remove_all_shadows_and_parents(d, omfn); - if ( sh_remove_all_mappings(d, omfn, - _gfn(gfn + (i << PAGE_SHIFT))) ) + if ( sh_remove_all_mappings(d, omfn, _gfn(gfn + i)) ) cpumask_or(&flushmask, &flushmask, d->dirty_cpumask); } omfn = mfn_add(omfn, 1);
Luckily sh_remove_all_mappings()'s use of the parameter is limited to generation of log messages. Nevertheless we'd better pass correct GFNs around: - the incoming GFN, when replacing a large page, may not be large page aligned, - incrementing by page-size-scaled values can't be right. Signed-off-by: Jan Beulich <jbeulich@suse.com>