On Fri, 30 Nov 2018 15:32:13 +0100
Michael Mueller <mimu@xxxxxxxxxxxxx> wrote:
> Add the IAM (Interruption Alert Mask) to the architectue specific
s/architectue/architecture/
> kvm struct. This mask in the GISA is used to define for which ISC
> a GIB alert can be issued.
>
> The functions kvm_s390_gisc_register() and kvm_s390_gisc_unregister()
> are used to (un)register a GISC (guest ISC) with a virtual machine and
> its GISA.
Add a note that these interfaces are supposed to be used by the
different adapter interrupt users like AP or PCI?
>
> Upon successful completion, kvm_s390_gisc_register() returns the
> ISC to be used for GIB alert interruptions. A negative return code
> indicates an error during registration.
>
> Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
> Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> ---
> arch/s390/include/asm/kvm_host.h | 6 ++++++
> arch/s390/kvm/interrupt.c | 44 ++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 50 insertions(+)
> +int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc)
> +{
> + int rc = 0;
> +
> + if (!kvm->arch.gib_in_use)
> + return -ENODEV;
> + if (gisc > MAX_ISC)
> + return -EINVAL;
> +
> + spin_lock(&kvm->arch.iam_ref_lock);
> + if (kvm->arch.iam_ref_count[gisc] == 0) {
> + rc = -EFAULT;
-EFAULT looks odd. -EINVAL?
> + goto out;
> + }
> + kvm->arch.iam_ref_count[gisc]--;
> + if (kvm->arch.iam_ref_count[gisc] == 0)
> + kvm->arch.iam &= ~(0x80 >> gisc);
> +out:
> + spin_unlock(&kvm->arch.iam_ref_lock);
> +
> + return rc;
> +}
> +EXPORT_SYMBOL_GPL(kvm_s390_gisc_unregister);
> +
> void kvm_s390_gib_destroy(void)
> {
> if (!gib)
