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authorCornelia Huck2012-12-20 15:32:12 +0100
committerMarcelo Tosatti2013-01-07 22:53:43 +0100
commitfa6b7fe9928d50444c29b29c8563746c6b0c6299 (patch)
tree0be284cf322eb82eefdb3df2743740e5578ba5c4 /arch/s390/kvm/kvm-s390.c
parentKVM: s390: Base infrastructure for enabling capabilities. (diff)
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KVM: s390: Add support for channel I/O instructions.
Add a new capability, KVM_CAP_S390_CSS_SUPPORT, which will pass intercepts for channel I/O instructions to userspace. Only I/O instructions interacting with I/O interrupts need to be handled in-kernel: - TEST PENDING INTERRUPTION (tpi) dequeues and stores pending interrupts entirely in-kernel. - TEST SUBCHANNEL (tsch) dequeues pending interrupts in-kernel and exits via KVM_EXIT_S390_TSCH to userspace for subchannel- related processing. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Reviewed-by: Alexander Graf <agraf@suse.de> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
-rw-r--r--arch/s390/kvm/kvm-s390.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 5ff26033825c..5b01f0953900 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -141,6 +141,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_SYNC_REGS:
case KVM_CAP_ONE_REG:
case KVM_CAP_ENABLE_CAP:
+ case KVM_CAP_S390_CSS_SUPPORT:
r = 1;
break;
case KVM_CAP_NR_VCPUS:
@@ -235,6 +236,9 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
if (!kvm->arch.gmap)
goto out_nogmap;
}
+
+ kvm->arch.css_support = 0;
+
return 0;
out_nogmap:
debug_unregister(kvm->arch.dbf);
@@ -658,6 +662,7 @@ rerun_vcpu:
case KVM_EXIT_INTR:
case KVM_EXIT_S390_RESET:
case KVM_EXIT_S390_UCONTROL:
+ case KVM_EXIT_S390_TSCH:
break;
default:
BUG();
@@ -818,6 +823,13 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
return -EINVAL;
switch (cap->cap) {
+ case KVM_CAP_S390_CSS_SUPPORT:
+ if (!vcpu->kvm->arch.css_support) {
+ vcpu->kvm->arch.css_support = 1;
+ trace_kvm_s390_enable_css(vcpu->kvm);
+ }
+ r = 0;
+ break;
default:
r = -EINVAL;
break;