From 853bcadeefe18ee0661a302811a17644b1f9e80b Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 15 Dec 2017 13:14:31 +0100 Subject: KVM: s390: fix cmma migration for multiple memory slots commit 32aa144fc32abfcbf7140f473dfbd94c5b9b4105 upstream. When multiple memory slots are present the cmma migration code does not allocate enough memory for the bitmap. The memory slots are sorted in reverse order, so we must use gfn and size of slot[0] instead of the last one. Signed-off-by: Christian Borntraeger Reviewed-by: Claudio Imbrenda Fixes: 190df4a212a7 (KVM: s390: CMMA tracking, ESSA emulation, migration mode) Reviewed-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/kvm-s390.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 40d0a1a97889..b87a930c2201 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -794,11 +794,12 @@ static int kvm_s390_vm_start_migration(struct kvm *kvm) if (kvm->arch.use_cmma) { /* - * Get the last slot. They should be sorted by base_gfn, so the - * last slot is also the one at the end of the address space. - * We have verified above that at least one slot is present. + * Get the first slot. They are reverse sorted by base_gfn, so + * the first slot is also the one at the end of the address + * space. We have verified above that at least one slot is + * present. */ - ms = slots->memslots + slots->used_slots - 1; + ms = slots->memslots; /* round up so we only use full longs */ ram_pages = roundup(ms->base_gfn + ms->npages, BITS_PER_LONG); /* allocate enough bytes to store all the bits */ -- cgit v1.2.3