From: Roger Pau Monne Date: Thu, 27 Dec 2018 15:26:35 +0000 (+0100) Subject: x86/dom0: allow stealing RAM from a region that starts in the low 1MB X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2689 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=667e916fca68e7a1d643a7e460c690626413b197;p=xen.git x86/dom0: allow stealing RAM from a region that starts in the low 1MB As long as the memory stolen is always above 1MB. This allows the PVH Dom0 builder to be used on a memory map that only has a single RAM region starting at 0. Reported-by: Andrew Cooper Signed-off-by: Roger Pau Monné Reviewed-by: Andrew Cooper Tested-by: Andrew Cooper --- diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c index 91dc27dc3e..24cc15f28b 100644 --- a/xen/arch/x86/hvm/dom0_build.c +++ b/xen/arch/x86/hvm/dom0_build.c @@ -154,12 +154,13 @@ static int __init pvh_steal_ram(struct domain *d, unsigned long size, { struct e820entry *entry = &d->arch.e820[i]; - if ( entry->type != E820_RAM || entry->addr + entry->size > limit || - entry->addr < MB(1) ) + if ( entry->type != E820_RAM || entry->addr + entry->size > limit ) continue; *addr = (entry->addr + entry->size - size) & ~(align - 1); - if ( *addr < entry->addr ) + if ( *addr < entry->addr || + /* Don't steal from the low 1MB due to the copying done there. */ + *addr < MB(1) ) continue; entry->size = *addr - entry->addr;