From 0349985add77ef5c9da8a75f4a9855977f4197d9 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Mon, 25 Aug 2014 12:38:57 +0200 Subject: [PATCH] KVM: s390: Limit guest size to 16TB Currently we fill up a full 5 level page table to hold the guest mapping. Since commit "support gmap page tables with less than 5 levels" we can do better. Having more than 4 TB might be useful for some testing scenarios, so let's just limit ourselves to 16TB guest size. Having more than that is totally untested as I do not have enough swap space/memory. We continue to allow ucontrol the full size. Signed-off-by: Christian Borntraeger Acked-by: Cornelia Huck Cc: Martin Schwidefsky --- arch/s390/kvm/kvm-s390.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 2037738..b95d4a4 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -458,7 +458,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) if (type & KVM_VM_S390_UCONTROL) { kvm->arch.gmap = NULL; } else { - kvm->arch.gmap = gmap_alloc(current->mm, -1UL); + kvm->arch.gmap = gmap_alloc(current->mm, (1UL << 44) - 1); if (!kvm->arch.gmap) goto out_nogmap; kvm->arch.gmap->private = kvm; -- 2.7.4