tree 06e098c4ba6b3f091a3262b60ff562069f73ee11
parent 7afbeb6df2aa5f9e3a0fc228817a85c16dea0faa
author Janosch Frank <frankja@linux.vnet.ibm.com> 1488464622 +0100
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1488471436 +0100

KVM: s390: Fix guest migration for huge guests resulting in panic

While we can technically not run huge page guests right now, we can
setup a guest with huge pages. Trying to migrate it will trigger a
VM_BUG_ON and, if the kernel is not configured to panic on a BUG, it
will happily try to work on non-existing page table entries.

With this patch, we always return "dirty" if we encounter a large page
when migrating. This at least fixes the immediate problem until we
have proper handling for both kind of pages.

Fixes: 15f36eb ("KVM: s390: Add proper dirty bitmap support to S390 kvm.")
Cc: <stable@vger.kernel.org> # 3.16+

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>