[RFC PATCH 1/1] KVM: PPC: Report single stepping capability

[Fabiano Rosas <farosas@linux.ibm.com>]

When calling the KVM_SET_GUEST_DEBUG ioctl, userspace might request
the next instruction to be single stepped via the
KVM_GUESTDBG_SINGLESTEP control bit of the kvm_guest_debug structure.

We currently don't have support for guest single stepping implemented
in Book3S HV.

This patch adds the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability in order
to inform userspace about the state of single stepping support.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
---
 arch/powerpc/kvm/powerpc.c | 5 +++++
 include/uapi/linux/kvm.h   | 1 +
 2 files changed, 6 insertions(+)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 8885377ec3e0..5ba990b0ec74 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -538,6 +538,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_IMMEDIATE_EXIT:
 		r = 1;
 		break;
+	case KVM_CAP_PPC_GUEST_DEBUG_SSTEP:
+#ifdef CONFIG_BOOKE
+		r = 1;
+		break;
+#endif
 	case KVM_CAP_PPC_PAIRED_SINGLES:
 	case KVM_CAP_PPC_OSI:
 	case KVM_CAP_PPC_GET_PVINFO:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 6d4ea4b6c922..33e8a4db867e 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -988,6 +988,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_ARM_VM_IPA_SIZE 165
 #define KVM_CAP_MANUAL_DIRTY_LOG_PROTECT 166
 #define KVM_CAP_HYPERV_CPUID 167
+#define KVM_CAP_PPC_GUEST_DEBUG_SSTEP 168
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
-- 
2.20.1