Re: [PATCH RFC 2/2] KVM: s390: vsie: store guest addresses of satellite blocks in vsie_page

[David Hildenbrand <david@xxxxxxxxxx>]

On 06.03.2018 12:53, Christian Borntraeger wrote:
> 
> 
> On 03/06/2018 12:38 PM, Christian Borntraeger wrote:
>> On 03/06/2018 12:32 PM, Christian Borntraeger wrote:
>>> David, 
>>>
>>> this seems to have broken VSIE für guests with >64vcpus as we only pin
>>> the first page of the SCA. Starting guest3 with 240 vcpu triggers
>>> quickly guest2 crashes. Can you have a look?
>>>
>>
>> Hmm, or maybe it was always broken and we never supported pinning of
>> ESCA properly?
> 
> 4.15.0 is also broken, must be an earlier change.
> 

Maybe something as simple as this:

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 77d7818130db..321bfbc67d3d 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2146,6 +2146,7 @@ static void sca_add_vcpu(struct kvm_vcpu *vcpu)
                /* we still need the basic sca for the ipte control */
                vcpu->arch.sie_block->scaoh = (__u32)(((__u64)sca) >> 32);
                vcpu->arch.sie_block->scaol = (__u32)(__u64)sca;
+               return;
        }
        read_lock(&vcpu->kvm->arch.sca_lock);
        if (vcpu->kvm->arch.use_esca) {


-- 

Thanks,

David / dhildenb