KVM: PPC: Book3S: Add infrastructure to implement kernel-side RTAS calls

For pseries machine emulation, in order to move the interrupt
controller code to the kernel, we need to intercept some RTAS
calls in the kernel itself.  This adds an infrastructure to allow
in-kernel handlers to be registered for RTAS services by name.
A new ioctl, KVM_PPC_RTAS_DEFINE_TOKEN, then allows userspace to
associate token values with those service names.  Then, when the
guest requests an RTAS service with one of those token values, it
will be handled by the relevant in-kernel handler rather than being
passed up to userspace as at present.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix warning]
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
index ee02b30878ed..4efa4a4f3722 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -246,6 +246,13 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
 		clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
 		vcpu->stat.halt_wakeup++;
 		return EMULATE_DONE;
+	case H_RTAS:
+		if (list_empty(&vcpu->kvm->arch.rtas_tokens))
+			return RESUME_HOST;
+		if (kvmppc_rtas_hcall(vcpu))
+			break;
+		kvmppc_set_gpr(vcpu, 3, 0);
+		return EMULATE_DONE;
 	}
 
 	return EMULATE_FAIL;