[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: Ingo Molnar <mingo@elte.hu>
Acked-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index ccc06b1..714f6a7 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -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 @@
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);