On 28.11.18 11:19, Michael Mueller wrote:
> This metric will allow to identify how many vcpus are currently
> running for a given kvm in SIE context. Its value is between 0 and
> the number of vcpus defined for the kvm guest, but never lager than
> the number of cpus available to the KVM host in total.
>
> This metric is required to decide if the GISA IAM has to be restored
> from the kvm arch field of the guest. That will be the case when no
> vcpu is in SIE context. (vcpus_in_sie == 0)
>
> Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
> Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> ---
> arch/s390/include/asm/kvm_host.h | 1 +
> arch/s390/kvm/kvm-s390.c | 4 ++++
> 2 files changed, 5 insertions(+)
>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index 537e5e59f27e..02227457945e 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -848,6 +848,7 @@ struct kvm_arch{
> DECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
> struct kvm_s390_gisa *gisa;
> int gib_in_use;
> + atomic_t vcpus_in_sie;
> };
>
> #define KVM_HVA_ERR_BAD (-1UL)
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 96954871b6a2..46dcf9ea59d3 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -3468,6 +3468,8 @@ static int vcpu_pre_run(struct kvm_vcpu *vcpu)
> kvm_s390_patch_guest_per_regs(vcpu);
> }
>
> + atomic_inc(&vcpu->kvm->arch.vcpus_in_sie);
> +
> vcpu->arch.sie_block->icptcode = 0;
> cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags);
> VCPU_EVENT(vcpu, 6, "entering sie flags %x", cpuflags);
> @@ -3527,6 +3529,8 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
> vcpu->run->s.regs.gprs[14] = vcpu->arch.sie_block->gg14;
> vcpu->run->s.regs.gprs[15] = vcpu->arch.sie_block->gg15;
>
> + atomic_dec(&vcpu->kvm->arch.vcpus_in_sie);
> +
> if (exit_reason == -EINTR) {
> VCPU_EVENT(vcpu, 3, "%s", "machine check");
> sie_page = container_of(vcpu->arch.sie_block,
>
I am wondering if we should move that directly around sie64a().
I guess we don't have to worry about vSIE here?
--
Thanks,
David / dhildenb
