Commit 07031e14 authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds
Browse files

[PATCH] KVM: add VM-exit profiling 



This adds the profile=kvm boot option, which enables KVM to profile VM
exits.

Use: "readprofile -m ./System.map | sort -n" to see the resulting
output:

   [...]
   18246 serial_out                               148.3415
   18945 native_flush_tlb                         378.9000
   23618 serial_in                                212.7748
   29279 __spin_unlock_irq                        622.9574
   43447 native_apic_write                        2068.9048
   52702 enable_8259A_irq                         742.2817
   54250 vgacon_scroll                             89.3740
   67394 ide_inb                                  6126.7273
   79514 copy_page_range                           98.1654
   84868 do_wp_page                                86.6000
  140266 pit_read                                 783.6089
  151436 ide_outb                                 25239.3333
  152668 native_io_delay                          21809.7143
  174783 mask_and_ack_8259A                       783.7803
  362404 native_set_pte_at                        36240.4000
 1688747 total                                      0.5009

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarAvi Kivity <avi@qumranet.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e3881a68

drivers/kvm/svm.c

+8 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/module.h>

#include <linux/vmalloc.h>

#include <linux/highmem.h>

#include <linux/profile.h>

#include <asm/desc.h>



#include "kvm_svm.h"
@@ -1558,6 +1559,13 @@ again: 


	reload_tss(vcpu);



	/*

	 * Profile KVM exit RIPs:

	 */

	if (unlikely(prof_on == KVM_PROFILING))

		profile_hit(KVM_PROFILING,

			(void *)(unsigned long)vcpu->svm->vmcb->save.rip);



	stgi();



	kvm_reput_irq(vcpu);

drivers/kvm/vmx.c

+7 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/module.h>

#include <linux/mm.h>

#include <linux/highmem.h>

#include <linux/profile.h>

#include <asm/io.h>

#include <asm/desc.h>
@@ -1859,6 +1860,12 @@ again: 
	asm ("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));

#endif



	/*

	 * Profile KVM exit RIPs:

	 */

	if (unlikely(prof_on == KVM_PROFILING))

		profile_hit(KVM_PROFILING, (void *)vmcs_readl(GUEST_RIP));



	kvm_run->exit_type = 0;

	if (fail) {

		kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY;

include/linux/profile.h

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ extern int prof_on __read_mostly; 
#define CPU_PROFILING	1

#define SCHED_PROFILING	2

#define SLEEP_PROFILING	3

#define KVM_PROFILING	4



struct proc_dir_entry;

struct pt_regs;

kernel/profile.c

+14 −0
Original line number Diff line number Diff line
@@ -40,7 +40,10 @@ int (*timer_hook)(struct pt_regs *) __read_mostly; 


static atomic_t *prof_buffer;

static unsigned long prof_len, prof_shift;



int prof_on __read_mostly;

EXPORT_SYMBOL_GPL(prof_on);



static cpumask_t prof_cpu_mask = CPU_MASK_ALL;

#ifdef CONFIG_SMP

static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
@@ -52,6 +55,7 @@ static int __init profile_setup(char * str) 
{

	static char __initdata schedstr[] = "schedule";

	static char __initdata sleepstr[] = "sleep";

	static char __initdata kvmstr[] = "kvm";

	int par;



	if (!strncmp(str, sleepstr, strlen(sleepstr))) {
@@ -72,6 +76,15 @@ static int __init profile_setup(char * str) 
		printk(KERN_INFO

			"kernel schedule profiling enabled (shift: %ld)\n",

			prof_shift);

	} else if (!strncmp(str, kvmstr, strlen(kvmstr))) {

		prof_on = KVM_PROFILING;

		if (str[strlen(kvmstr)] == ',')

			str += strlen(kvmstr) + 1;

		if (get_option(&str, &par))

			prof_shift = par;

		printk(KERN_INFO

			"kernel KVM profiling enabled (shift: %ld)\n",

			prof_shift);

	} else if (get_option(&str, &par)) {

		prof_shift = par;

		prof_on = CPU_PROFILING;
@@ -318,6 +331,7 @@ out: 
	local_irq_restore(flags);

	put_cpu();

}

EXPORT_SYMBOL_GPL(profile_hits);



static int __devinit profile_cpu_callback(struct notifier_block *info,

					unsigned long action, void *__cpu)

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