Re: [PATCH] KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctl

[Thomas Huth]

On 13/09/2019 09.20, Cornelia Huck wrote:
> On Thu, 12 Sep 2019 13:23:38 +0200
> Thomas Huth <thuth@xxxxxxxxxx> wrote:
> 
>> Hmm, we already talked about deprecating support for pre-3.15 kernel
>> stuff in the past (see
>> https://wiki.qemu.org/ChangeLog/2.12#Future_incompatible_changes for
>> example),
> 
> Btw: did we ever do that? I don't quite recall what code we were
> talking about...

We never really did - but we also never fixed the issue: If you run the
current QEMU on a kernel before 3.15, it refuses to work due to the
missing in-kernel FLIC device:

Initialization of device s390-flic-kvm failed: KVM is missing capability
KVM_CAP_DEVICE_CTR

Since nobody really complained so far that running QEMU with KVM is
still required on a kernel < 3.15, I think we could make this also
"official" now and improve the error message a little bit, pointing the
user to a kernel >= 3.15.

 Thomas