On 09/10/2018 19:52, Tony Krowiak wrote:
> From: Tony Krowiak <akrow...@linux.ibm.com>
>
> Let's use the KVM_SET_DEVICE_ATTR ioctl to enable hardware
> interpretation of AP instructions executed on the guest.
> If the S390_FEAT_AP feature is switched on for the guest,
> AP instructions must be interpreted by default; otherwise,
> they will be intercepted.
>
> This attribute setting may be overridden by a device. For example,
> a device may want to provide AP instructions to the guest (i.e.,
> S390_FEAT_AP turned on), but it may want to emulate them. In this
> case, the AP instructions executed on the guest must be
> intercepted; so when the device is realized, it must disable
> interpretation.
>
> Signed-off-by: Tony Krowiak <akrow...@linux.ibm.com>
> Tested-by: Pierre Morel<pmo...@linux.ibm.com>
> ---
> target/s390x/kvm.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index 348e8cc5467a..d042deed1af3 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -2291,11 +2291,26 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model,
> Error **errp)
> error_setg(errp, "KVM: host CPU model could not be identified");
> return;
> }
> + /* for now, we can only provide the AP feature with HW support */
> + if (kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO,
> + KVM_S390_VM_CRYPTO_ENABLE_APIE)) {
> + set_bit(S390_FEAT_AP, model->features);
> + }
> /* strip of features that are not part of the maximum model */
> bitmap_and(model->features, model->features, model->def->full_feat,
> S390_FEAT_MAX);
> }
>
> +static void kvm_s390_configure_apie(bool interpret)
> +{
> + uint64_t attr = interpret ? KVM_S390_VM_CRYPTO_ENABLE_APIE :
> + KVM_S390_VM_CRYPTO_DISABLE_APIE;
> +
> + if (kvm_vm_check_attr(kvm_state, KVM_S390_VM_CRYPTO, attr)) {
> + kvm_s390_set_attr(attr);
> + }
> +}
> +
> void kvm_s390_apply_cpu_model(const S390CPUModel *model, Error **errp)
> {
> struct kvm_s390_vm_cpu_processor prop = {
> @@ -2345,6 +2360,10 @@ void kvm_s390_apply_cpu_model(const S390CPUModel
> *model, Error **errp)
> if (test_bit(S390_FEAT_CMM, model->features)) {
> kvm_s390_enable_cmma();
> }
> +
> + if (test_bit(S390_FEAT_AP, model->features)) {
> + kvm_s390_configure_apie(true);
> + }
> }
>
> void kvm_s390_restart_interrupt(S390CPU *cpu)
>
Reviewed-by: David Hildenbrand <da...@redhat.com>
--
Thanks,
David / dhildenb
