[PATCH 2/4] KVM: PPC: epapr: Add idle hcall support for host

[Stuart Yoder <stuart.yoder@freescale.com>]

From: Liu Yu-B13201 <Yu.Liu@freescale.com>

And add a new flag definition in kvm_ppc_pvinfo to indicate
whether host support EV_IDLE hcall.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
---
 arch/powerpc/include/asm/Kbuild     |    1 +
 arch/powerpc/include/asm/kvm_para.h |   14 ++++++++++++--
 arch/powerpc/kvm/booke.c            |    6 ++++++
 arch/powerpc/kvm/powerpc.c          |    9 +++++++--
 include/linux/kvm.h                 |    2 ++
 5 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
index d51df17..b68cb1c 100644
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -34,3 +34,4 @@ header-y += termios.h
 header-y += types.h
 header-y += ucontext.h
 header-y += unistd.h
+header-y += epapr_hcalls.h
diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
index b3b4667..5617c8c 100644
--- a/arch/powerpc/include/asm/kvm_para.h
+++ b/arch/powerpc/include/asm/kvm_para.h
@@ -90,9 +90,19 @@ struct kvm_vcpu_arch_shared {
 };
 
 #define KVM_SC_MAGIC_R0		0x4b564d21 /* "KVM!" */
-#define HC_VENDOR_KVM		(42 << 16)
+
+#include <asm/epapr_hcalls.h>
+
+/* ePAPR Hypercall Vendor ID */
+#define HC_VENDOR_EPAPR		(EV_EPAPR_VENDOR_ID << 16)
+#define HC_VENDOR_KVM		(EV_KVM_VENDOR_ID << 16)
+
+/* ePAPR Hypercall Token */
+#define HC_EV_IDLE		EV_IDLE
+
+/* ePAPR Hypercall Return Codes */
 #define HC_EV_SUCCESS		0
-#define HC_EV_UNIMPLEMENTED	12
+#define HC_EV_UNIMPLEMENTED	EV_UNIMPLEMENTED
 
 #define KVM_FEATURE_MAGIC_PAGE	1
 
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index f0ef0be..9fde645 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -593,6 +593,12 @@ static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
 	unsigned int priority;
 
 	if (vcpu->requests) {
+		/* kvm_vcpu_block() sets KVM_REQ_UNHALT, but it is
+ 		 * not cleared elsewhere as on x86.  Clear it here
+ 		 * for now, otherwise we never go idle.
+ 		 */
+		clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+
 		if (kvm_check_request(KVM_REQ_PENDING_TIMER, vcpu)) {
 			smp_mb();
 			update_timer_ints(vcpu);
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index ee489f4..a971c51 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -48,8 +48,7 @@ static unsigned int perfmon_refcount;
 
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
-	bool ret = !(v->arch.shared->msr & MSR_WE) ||
-		   !!(v->arch.pending_exceptions) ||
+	bool ret = !!(v->arch.pending_exceptions) ||
 		   v->requests;
 
 #ifdef CONFIG_BOOKE
@@ -100,6 +99,10 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
 
 		/* Second return value is in r4 */
 		break;
+	case HC_VENDOR_EPAPR | HC_EV_IDLE:
+		r = HC_EV_SUCCESS;
+		kvm_vcpu_block(vcpu);
+		break;
 	default:
 		r = HC_EV_UNIMPLEMENTED;
 		break;
@@ -908,6 +911,8 @@ static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
 	pvinfo->hcall[2] = inst_sc;
 	pvinfo->hcall[3] = inst_nop;
 
+	pvinfo->flags = KVM_PPC_PVINFO_FLAGS_EV_IDLE;
+
 	return 0;
 }
 
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 28ced78..32b8f54 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -438,6 +438,8 @@ struct kvm_ppc_pvinfo {
 	__u8  pad[108];
 };
 
+#define KVM_PPC_PVINFO_FLAGS_EV_IDLE   (1<<0)
+
 #define KVMIO 0xAE
 
 /*
-- 
1.7.3.4