From aca411a4b17a4aebe14ecdf253373db5b7ee6058 Mon Sep 17 00:00:00 2001 From: Julius Niedworok Date: Wed, 3 Aug 2016 16:39:55 +0200 Subject: [PATCH] KVM: s390: reset KVM_REQ_MMU_RELOAD if mapping the prefix failed When triggering KVM_RUN without a user memory region being mapped (KVM_SET_USER_MEMORY_REGION) a validity intercept occurs. This could happen, if the user memory region was not mapped initially or if it was unmapped after the vcpu is initialized. The function kvm_s390_handle_requests checks for the KVM_REQ_MMU_RELOAD bit. The check function always clears this bit. If gmap_mprotect_notify returns an error code, the mapping failed, but the KVM_REQ_MMU_RELOAD was not set anymore. So the next time kvm_s390_handle_requests is called, the execution would fall trough the check for KVM_REQ_MMU_RELOAD. The bit needs to be resetted, if gmap_mprotect_notify returns an error code. Resetting the bit with kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu) fixes the bug. Reviewed-by: David Hildenbrand Signed-off-by: Julius Niedworok Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index e63f6ed0a936..f142215ed30d 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2362,8 +2362,10 @@ retry: rc = gmap_mprotect_notify(vcpu->arch.gmap, kvm_s390_get_prefix(vcpu), PAGE_SIZE * 2, PROT_WRITE); - if (rc) + if (rc) { + kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu); return rc; + } goto retry; } -- 2.20.1