From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Borntraeger Subject: [PATCH 1/1] KVM: s390: fix cmma migration for multiple memory slots Date: Tue, 19 Dec 2017 09:19:21 +0100 Message-ID: <20171219081921.81670-2-borntraeger@de.ibm.com> References: <20171219081921.81670-1-borntraeger@de.ibm.com> Return-path: In-Reply-To: <20171219081921.81670-1-borntraeger@de.ibm.com> Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Cornelia Huck Cc: KVM , Christian Borntraeger , linux-s390 , Thomas Huth , Halil Pasic , Janosch Frank , Claudio Imbrenda List-ID: 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 Cc: stable@vger.kernel.org # 4.13+ Fixes: 190df4a212a7 (KVM: s390: CMMA tracking, ESSA emulation, migration mode) --- 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 966ea611210a..3373d8dff131 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -792,11 +792,12 @@ 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 */ -- 2.13.4