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Message-ID: <1372341272-12512-4-git-send-email-stefano.stabellini@eu.citrix.com>
Date: Thu, 27 Jun 2013 14:54:31 +0100
From: Stefano Stabellini <stefano.stabellini@...citrix.com>
To: <xen-devel@...ts.xensource.com>
CC: <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>, <konrad.wilk@...cle.com>,
<catalin.marinas@....com>, <arnd@...db.de>, <olof@...om.net>,
<linux@....linux.org.uk>, <Ian.Campbell@...rix.com>,
<Stefano.Stabellini@...citrix.com>, <will.deacon@....com>,
<marc.zyngier@....com>,
Stefano Stabellini <stefano.stabellini@...citrix.com>,
<nico@...aro.org>, <cov@...eaurora.org>, <Catalin.Marinas@....com>
Subject: [PATCH v6 4/5] arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops
Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64.
Necessary duplication of paravirt.h and paravirt.c with ARM.
The only paravirt interface supported is pv_time_ops.steal_clock, so no
runtime pvops patching needed.
This allows us to make use of steal_account_process_tick for stolen
ticks accounting.
Signed-off-by: Stefano Stabellini <stefano.stabellini@...citrix.com>
CC: will.deacon@....com
CC: nico@...aro.org
CC: marc.zyngier@....com
CC: cov@...eaurora.org
CC: arnd@...db.de
CC: olof@...om.net
CC: Catalin.Marinas@....com
---
arch/arm64/Kconfig | 20 ++++++++++++++++++++
arch/arm64/include/asm/paravirt.h | 19 +++++++++++++++++++
arch/arm64/kernel/Makefile | 1 +
arch/arm64/kernel/paravirt.c | 25 +++++++++++++++++++++++++
4 files changed, 65 insertions(+), 0 deletions(-)
create mode 100644 arch/arm64/include/asm/paravirt.h
create mode 100644 arch/arm64/kernel/paravirt.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1fac4e5..4c4f213 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -190,6 +190,25 @@ config HW_PERF_EVENTS
source "mm/Kconfig"
+config PARAVIRT
+ bool "Enable paravirtualization code"
+ ---help---
+ This changes the kernel so it can modify itself when it is run
+ under a hypervisor, potentially improving performance significantly
+ over full virtualization.
+
+config PARAVIRT_TIME_ACCOUNTING
+ bool "Paravirtual steal time accounting"
+ select PARAVIRT
+ default n
+ ---help---
+ Select this option to enable fine granularity task steal time
+ accounting. Time spent executing other tasks in parallel with
+ the current vCPU is discounted from the vCPU power. To account for
+ that, there can be a small performance impact.
+
+ If in doubt, say N here.
+
config XEN_DOM0
def_bool y
depends on XEN
@@ -197,6 +216,7 @@ config XEN_DOM0
config XEN
bool "Xen guest support on ARM64 (EXPERIMENTAL)"
depends on ARM64 && OF
+ select PARAVIRT
help
Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h
new file mode 100644
index 0000000..54e895b
--- /dev/null
+++ b/arch/arm64/include/asm/paravirt.h
@@ -0,0 +1,19 @@
+#ifndef _ASM_ARM64_PARAVIRT_H
+#define _ASM_ARM64_PARAVIRT_H
+
+struct static_key;
+extern struct static_key paravirt_steal_enabled;
+extern struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops {
+ unsigned long long (*steal_clock)(int cpu);
+};
+extern struct pv_time_ops pv_time_ops;
+
+static inline u64 paravirt_steal_clock(int cpu)
+{
+ return pv_time_ops.steal_clock(cpu);
+}
+
+
+#endif
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 7b4b564..17613ad 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -18,6 +18,7 @@ arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o smp_psci.o
arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
arm64-obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o
obj-y += $(arm64-obj-y) vdso/
obj-m += $(arm64-obj-m)
diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
new file mode 100644
index 0000000..53f371e
--- /dev/null
+++ b/arch/arm64/kernel/paravirt.c
@@ -0,0 +1,25 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2013 Citrix Systems
+ *
+ * Author: Stefano Stabellini <stefano.stabellini@...citrix.com>
+ */
+
+#include <linux/export.h>
+#include <linux/jump_label.h>
+#include <linux/types.h>
+#include <asm/paravirt.h>
+
+struct static_key paravirt_steal_enabled;
+struct static_key paravirt_steal_rq_enabled;
+
+struct pv_time_ops pv_time_ops;
+EXPORT_SYMBOL_GPL(pv_time_ops);
--
1.7.2.5
--
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