While 670d6b908ff2 ('x86 shadow: Move the shadow linear mapping for n-on-3-on-4 shadows so') bumped the amount by one too little for the 32-on-64 case (which luckily was dead code, and hence a bump wasn't necessary in the first place), 0b841314dace ('x86/shadow: sh_{make,destroy}_monitor_table() are "even more" HVM-only'), dropping the dead code, then didn't adjust the amount back. Yet even the original amount was too high in certain cases. Switch to pre-allocating just as much as is going to be needed.
Signed-off-by: Jan Beulich <jbeul...@suse.com> --- a/xen/arch/x86/mm/shadow/hvm.c +++ b/xen/arch/x86/mm/shadow/hvm.c @@ -726,7 +726,7 @@ mfn_t sh_make_monitor_table(const struct ASSERT(!pagetable_get_pfn(v->arch.hvm.monitor_table)); /* Guarantee we can get the memory we need */ - if ( !shadow_prealloc(d, SH_type_monitor_table, CONFIG_PAGING_LEVELS) ) + if ( !shadow_prealloc(d, SH_type_monitor_table, shadow_levels < 4 ? 3 : 1) ) return INVALID_MFN; m4mfn = shadow_alloc(d, SH_type_monitor_table, 0);