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List:       kvm
Subject:    [PATCH 2/2] KVM: PPC: epapr: Install ev_idle hcall for paravirt guest linux
From:       Liu Yu <yu.liu () freescale ! com>
Date:       2011-12-31 6:16:16
Message-ID: 1325312176-17697-2-git-send-email-yu.liu () freescale ! com
[Download RAW message or body]

If the guest hypervisor node contains "has-idle" property.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
---
 arch/powerpc/kernel/kvm.c |   29 +++++++++++++++++++++++++++++
 1 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index b06bdae..258f129 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -28,6 +28,7 @@
 #include <asm/sections.h>
 #include <asm/cacheflush.h>
 #include <asm/disassemble.h>
+#include <asm/machdep.h>
 
 #define KVM_MAGIC_PAGE		(-4096L)
 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
@@ -571,6 +572,30 @@ static __init void kvm_free_tmp(void)
 	}
 }
 
+static void kvm_hcall_ev_idle(void)
+{
+	ulong in[8];
+	ulong out[8];
+
+	current_thread_info()->local_flags |= _TLF_NAPPING;
+	local_irq_enable();
+	kvm_hypercall(in, out, HC_VENDOR_EPAPR | HC_EV_IDLE);
+}
+
+static int kvm_para_ev_has_idle(void)
+{
+	struct device_node *hyper_node;
+
+	hyper_node = of_find_node_by_path("/hypervisor");
+	if (!hyper_node)
+		return 0;
+
+	if (of_get_property(hyper_node, "has-idle", NULL))
+		return 1;
+
+	return 0;
+}
+
 static int __init kvm_guest_init(void)
 {
 	if (!kvm_para_available())
@@ -587,6 +612,10 @@ static int __init kvm_guest_init(void)
 	powersave_nap = 1;
 #endif
 
+	/* Install hcall EV_IDLE based power_save for guest kernel */
+	if (kvm_para_ev_has_idle())
+		ppc_md.power_save = kvm_hcall_ev_idle;
+
 free_tmp:
 	kvm_free_tmp();
 
-- 
1.6.4


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