KVM: PPC: Factor out guest epapr initialization

epapr paravirtualization support is now a Kconfig
selectable option

Signed-off-by: Liu Yu <yu.liu@freescale.com>
[stuart.yoder@freescale.com: misc minor fixes, description update]
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

7 files changed, 92 insertions, 35 deletions

diff --git a/arch/powerpc/include/asm/epapr_hcalls.h b/arch/powerpc/include/asm/epapr_hcalls.h
index 976835d8f22e..bf2c06c33871 100644
--- a/arch/powerpc/include/asm/epapr_hcalls.h
+++ b/arch/powerpc/include/asm/epapr_hcalls.h
@@ -153,6 +153,8 @@
 #define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5"
 #define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4"
 
+extern bool epapr_paravirt_enabled;
+extern u32 epapr_hypercall_start[];
 
 /*
  * We use "uintptr_t" to define a register because it's guaranteed to be a
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 83afacd3ba7b..bb282dd81612 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -128,6 +128,7 @@ ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC),)
 obj-y                           += ppc_save_regs.o
 endif
 
+obj-$(CONFIG_EPAPR_PARAVIRT)    += epapr_paravirt.o epapr_hcalls.o
 obj-$(CONFIG_KVM_GUEST)         += kvm.o kvm_emul.o
 
 # Disable GCOV in odd or sensitive code
diff --git a/arch/powerpc/kernel/epapr_hcalls.S b/arch/powerpc/kernel/epapr_hcalls.S
new file mode 100644
index 000000000000..697b390ebfd8
--- /dev/null
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/threads.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+/* Hypercall entry point. Will be patched with device tree instructions. */
+.global epapr_hypercall_start
+epapr_hypercall_start:
+        li      r3, -1
+        nop
+        nop
+        nop
+        blr
diff --git a/arch/powerpc/kernel/epapr_paravirt.c b/arch/powerpc/kernel/epapr_paravirt.c
new file mode 100644
index 000000000000..028aeae370b6
--- /dev/null
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -0,0 +1,52 @@
+/*
+ * ePAPR para-virtualization support.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/of.h>
+#include <asm/epapr_hcalls.h>
+#include <asm/cacheflush.h>
+#include <asm/code-patching.h>
+
+bool epapr_paravirt_enabled;
+
+static int __init epapr_paravirt_init(void)
+{
+        struct device_node *hyper_node;
+        const u32 *insts;
+        int len, i;
+
+        hyper_node = of_find_node_by_path("/hypervisor");
+        if (!hyper_node)
+                return -ENODEV;
+
+        insts = of_get_property(hyper_node, "hcall-instructions", &len);
+        if (!insts)
+                return -ENODEV;
+
+        if (len % 4 || len > (4 * 4))
+                return -ENODEV;
+
+        for (i = 0; i < (len / 4); i++)
+                patch_instruction(epapr_hypercall_start + i, insts[i]);
+
+        epapr_paravirt_enabled = true;
+
+        return 0;
+}
+
+early_initcall(epapr_paravirt_init);
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 62bdf2389669..1c13307e0308 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -31,6 +31,7 @@
 #include <asm/cacheflush.h>
 #include <asm/disassemble.h>
 #include <asm/ppc-opcode.h>
+#include <asm/epapr_hcalls.h>
 
 #define KVM_MAGIC_PAGE          (-4096L)
 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
@@ -726,7 +727,7 @@ unsigned long kvm_hypercall(unsigned long *in,
         unsigned long register r11 asm("r11") = nr;
         unsigned long register r12 asm("r12");
 
-        asm volatile("bl        kvm_hypercall_start"
+        asm volatile("bl        epapr_hypercall_start"
                      : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
                        "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
                        "=r"(r12)
@@ -747,29 +748,6 @@ unsigned long kvm_hypercall(unsigned long *in,
 }
 EXPORT_SYMBOL_GPL(kvm_hypercall);
 
-static int kvm_para_setup(void)
-{
-        extern u32 kvm_hypercall_start;
-        struct device_node *hyper_node;
-        u32 *insts;
-        int len, i;
-
-        hyper_node = of_find_node_by_path("/hypervisor");
-        if (!hyper_node)
-                return -1;
-
-        insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
-        if (len % 4)
-                return -1;
-        if (len > (4 * 4))
-                return -1;
-
-        for (i = 0; i < (len / 4); i++)
-                kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);
-
-        return 0;
-}
-
 static __init void kvm_free_tmp(void)
 {
         unsigned long start, end;
@@ -791,7 +769,7 @@ static int __init kvm_guest_init(void)
         if (!kvm_para_available())
                 goto free_tmp;
 
-        if (kvm_para_setup())
+        if (!epapr_paravirt_enabled)
                 goto free_tmp;
 
         if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S
index e291cf3cf954..62ceb2ac82cf 100644
--- a/arch/powerpc/kernel/kvm_emul.S
+++ b/arch/powerpc/kernel/kvm_emul.S
@@ -24,16 +24,6 @@
 #include <asm/page.h>
 #include <asm/asm-offsets.h>
 
-/* Hypercall entry point. Will be patched with device tree instructions. */
-
-.global kvm_hypercall_start
-kvm_hypercall_start:
-        li      r3, -1
-        nop
-        nop
-        nop
-        blr
-
 #define KVM_MAGIC_PAGE          (-4096)
 
 #ifdef CONFIG_64BIT
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index a35ca44ade66..e7a896acd982 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -25,6 +25,7 @@ source "arch/powerpc/platforms/wsp/Kconfig"
 config KVM_GUEST
         bool "KVM Guest support"
         default n
+        select EPAPR_PARAVIRT
         ---help---
           This option enables various optimizations for running under the KVM
           hypervisor. Overhead for the kernel when not running inside KVM should
@@ -32,6 +33,14 @@ config KVM_GUEST
 
           In case of doubt, say Y
 
+config EPAPR_PARAVIRT
+        bool "ePAPR para-virtualization support"
+        default n
+        help
+          Enables ePAPR para-virtualization support for guests.
+
+          In case of doubt, say Y
+
 config PPC_NATIVE
         bool
         depends on 6xx || PPC64