From 3c404b578fab699c4708279938078d9404b255a4 Mon Sep 17 00:00:00 2001
From: Glauber Costa <glommer@redhat.com>
Date: Mon, 11 Jul 2011 15:28:15 -0400
Subject: [PATCH] KVM guest: Add a pv_ops stub for steal time
This patch adds a function pointer in one of the many paravirt_ops
structs, to allow guests to register a steal time function. Besides
a steal time function, we also declare two jump_labels. They will be
used to allow the steal time code to be easily bypassed when not
in use.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/include/asm/paravirt.h | 9 +++++++++
arch/x86/include/asm/paravirt_types.h | 1 +
arch/x86/kernel/paravirt.c | 9 +++++++++
3 files changed, 19 insertions(+)
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index ebbc4d8ab170..a7d2db9a74fb 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -230,6 +230,15 @@ static inline unsigned long long paravirt_sched_clock(void)
return PVOP_CALL0(unsigned long long, pv_time_ops.sched_clock);
}
+struct jump_label_key;
+extern struct jump_label_key paravirt_steal_enabled;
+extern struct jump_label_key paravirt_steal_rq_enabled;
+
+static inline u64 paravirt_steal_clock(int cpu)
+{
+ return PVOP_CALL1(u64, pv_time_ops.steal_clock, cpu);
+}
+
static inline unsigned long long paravirt_read_pmc(int counter)
{
return PVOP_CALL1(u64, pv_cpu_ops.read_pmc, counter);
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 82885099c869..2c7652163111 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -89,6 +89,7 @@ struct pv_lazy_ops {
struct pv_time_ops {
unsigned long long (*sched_clock)(void);
+ unsigned long long (*steal_clock)(int cpu);
unsigned long (*get_tsc_khz)(void);
};
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 869e1aeeb71b..613a7931ecc1 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -202,6 +202,14 @@ static void native_flush_tlb_single(unsigned long addr)
__native_flush_tlb_single(addr);
}
+struct jump_label_key paravirt_steal_enabled;
+struct jump_label_key paravirt_steal_rq_enabled;
+
+static u64 native_steal_clock(int cpu)
+{
+ return 0;
+}
+
/* These are in entry.S */
extern void native_iret(void);
extern void native_irq_enable_sysexit(void);
@@ -307,6 +315,7 @@ struct pv_init_ops pv_init_ops = {
struct pv_time_ops pv_time_ops = {
.sched_clock = native_sched_clock,
+ .steal_clock = native_steal_clock,
};
struct pv_irq_ops pv_irq_ops = {