Patchwork [v6,1/4] KVM: PPC: epapr: Factor out the epapr init

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Submitter Liu Yu-B13201
Date Feb. 23, 2012, 9:22 a.m.
Message ID <1329988942-19610-1-git-send-email-yu.liu@freescale.com>
Download mbox | patch
Permalink /patch/142576/
State New
Headers show

Comments

Liu Yu-B13201 - Feb. 23, 2012, 9:22 a.m.
from the kvm guest paravirt init code.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
---
v6:
1. rename epapr_para to epapr_paravirt
2. remove redundant warnings
3. remove unnecessary init

 arch/powerpc/include/asm/epapr_hcalls.h |    2 +
 arch/powerpc/kernel/Makefile            |    1 +
 arch/powerpc/kernel/epapr_hcalls.S      |   25 ++++++++++++++
 arch/powerpc/kernel/epapr_paravirt.c    |   54 +++++++++++++++++++++++++++++++
 arch/powerpc/kernel/kvm.c               |   28 ++--------------
 arch/powerpc/kernel/kvm_emul.S          |   10 ------
 arch/powerpc/platforms/Kconfig          |    9 +++++
 7 files changed, 94 insertions(+), 35 deletions(-)
 create mode 100644 arch/powerpc/kernel/epapr_hcalls.S
 create mode 100644 arch/powerpc/kernel/epapr_paravirt.c
Scott Wood - Feb. 27, 2012, 8:52 p.m.
On 02/23/2012 03:22 AM, Liu Yu wrote:
> +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 0;

-ENODEV here too.

> +	if (!(len % 4) && len <= (4 * 4)) {
> +		for (i = 0; i < (len / 4); i++)
> +			patch_instruction(epapr_hypercall_start + i, insts[i]);
> +
> +		epapr_paravirt_enabled = true;
> +	} else {
> +		printk(KERN_WARNING
> +		       "ePAPR paravirt: hcall-instructions format error\n");
> +	}

Do this:

if (error) {
	print error
	return error code
}

continue with function

Not this:

if (!error) {
	continue with function
} else {
	report the error from several lines back
}

> @@ -33,6 +34,14 @@ config KVM_GUEST
>  
>  	  In case of doubt, say Y
>  
> +config EPAPR_PARAVIRT
> +	bool "ePAPR para-virtualization support"
> +	default n
> +	help
> +	  Used to enalbe ePAPR complied para-virtualization support for guest.
> +
> +	  In case of doubt, say Y

s/Used to enalbe/Enable/

s/complied/compliant/ (or just s/complied//)

-Scott

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Patch

diff --git a/arch/powerpc/include/asm/epapr_hcalls.h b/arch/powerpc/include/asm/epapr_hcalls.h
index f3b0c2c..2173d4c 100644
--- a/arch/powerpc/include/asm/epapr_hcalls.h
+++ b/arch/powerpc/include/asm/epapr_hcalls.h
@@ -148,6 +148,8 @@ 
 #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 ee728e4..ba8fa43 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -136,6 +136,7 @@  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 0000000..697b390
--- /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 0000000..45eb439
--- /dev/null
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -0,0 +1,54 @@ 
+/*
+ * 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 0;
+
+	if (!(len % 4) && len <= (4 * 4)) {
+		for (i = 0; i < (len / 4); i++)
+			patch_instruction(epapr_hypercall_start + i, insts[i]);
+
+		epapr_paravirt_enabled = true;
+	} else {
+		printk(KERN_WARNING
+		       "ePAPR paravirt: hcall-instructions format error\n");
+	}
+
+	return 0;
+}
+
+early_initcall(epapr_paravirt_init);
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 62bdf23..1c13307 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 e291cf3..62ceb2a 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 0cfb46d..845690f 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -26,6 +26,7 @@  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
@@ -33,6 +34,14 @@  config KVM_GUEST
 
 	  In case of doubt, say Y
 
+config EPAPR_PARAVIRT
+	bool "ePAPR para-virtualization support"
+	default n
+	help
+	  Used to enalbe ePAPR complied para-virtualization support for guest.
+
+	  In case of doubt, say Y
+
 config PPC_NATIVE
 	bool
 	depends on 6xx || PPC64