powerpc/kvm/book3s: Add support for H_IPOLL and H_XIRR_X in XICS emulation

This adds the remaining two hypercalls defined by PAPR for manipulating
the XICS interrupt controller, H_IPOLL and H_XIRR_X.  H_IPOLL returns
information about the priority and pending interrupts for a virtual
cpu, without changing any state.  H_XIRR_X is like H_XIRR in that it
reads and acknowledges the highest-priority pending interrupt, but it
also returns the timestamp (timebase register value) from when the
interrupt was first received by the hypervisor.  Currently we just
return the current time, since we don't do any software queueing of
virtual interrupts inside the XICS emulation code.

These hcalls are not currently used by Linux guests, but may be in
future.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index f7a103756618..94c1dd46b83d 100644
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -650,6 +650,23 @@ static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
 	return H_SUCCESS;
 }
 
+static int kvmppc_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
+{
+	union kvmppc_icp_state state;
+	struct kvmppc_icp *icp;
+
+	icp = vcpu->arch.icp;
+	if (icp->server_num != server) {
+		icp = kvmppc_xics_find_server(vcpu->kvm, server);
+		if (!icp)
+			return H_PARAMETER;
+	}
+	state = ACCESS_ONCE(icp->state);
+	kvmppc_set_gpr(vcpu, 4, ((u32)state.cppr << 24) | state.xisr);
+	kvmppc_set_gpr(vcpu, 5, state.mfrr);
+	return H_SUCCESS;
+}
+
 static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
 {
 	union kvmppc_icp_state old_state, new_state;
@@ -787,6 +804,18 @@ int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
 	if (!xics || !vcpu->arch.icp)
 		return H_HARDWARE;
 
+	/* These requests don't have real-mode implementations at present */
+	switch (req) {
+	case H_XIRR_X:
+		res = kvmppc_h_xirr(vcpu);
+		kvmppc_set_gpr(vcpu, 4, res);
+		kvmppc_set_gpr(vcpu, 5, get_tb());
+		return rc;
+	case H_IPOLL:
+		rc = kvmppc_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
+		return rc;
+	}
+
 	/* Check for real mode returning too hard */
 	if (xics->real_mode)
 		return kvmppc_xics_rm_complete(vcpu, req);