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authorMarc Zyngier <Marc.Zyngier@arm.com>2012-09-13 16:40:46 +0100
committerWill Deacon <will.deacon@arm.com>2012-11-09 11:37:24 +0000
commite50c54189f7c6211a99539156e3978474f0b1a0b (patch)
treef2875cfc036a202270427471dd53e16f0ae48381 /arch/arm
parent3d70f8c617a436c7146ecb81df2265b4626dfe89 (diff)
downloadvexpress-lsk-e50c54189f7c6211a99539156e3978474f0b1a0b.tar.gz
ARM: perf: add guest vs host discrimination
Add minimal guest support to perf, so it can distinguish whether the PMU interrupt was in the host or the guest, as well as collecting some very basic information (guest PC, user vs kernel mode). This is not feature complete though, as it doesn't support backtracing in the guest. Based on the x86 implementation, tested with KVM/ARM. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/perf_event.h5
-rw-r--r--arch/arm/kernel/perf_event.c36
2 files changed, 41 insertions, 0 deletions
diff --git a/arch/arm/include/asm/perf_event.h b/arch/arm/include/asm/perf_event.h
index 625cd621a43..00416edecea 100644
--- a/arch/arm/include/asm/perf_event.h
+++ b/arch/arm/include/asm/perf_event.h
@@ -21,4 +21,9 @@
#define C(_x) PERF_COUNT_HW_CACHE_##_x
#define CACHE_OP_UNSUPPORTED 0xFFFF
+struct pt_regs;
+extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
+extern unsigned long perf_misc_flags(struct pt_regs *regs);
+#define perf_misc_flags(regs) perf_misc_flags(regs)
+
#endif /* __ARM_PERF_EVENT_H__ */
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 53c0304b734..f8406af0327 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -576,6 +576,10 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct frame_tail __user *tail;
+ if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ /* We don't support guest os callchain now */
+ return;
+ }
tail = (struct frame_tail __user *)regs->ARM_fp - 1;
@@ -603,9 +607,41 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs)
{
struct stackframe fr;
+ if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ /* We don't support guest os callchain now */
+ return;
+ }
+
fr.fp = regs->ARM_fp;
fr.sp = regs->ARM_sp;
fr.lr = regs->ARM_lr;
fr.pc = regs->ARM_pc;
walk_stackframe(&fr, callchain_trace, entry);
}
+
+unsigned long perf_instruction_pointer(struct pt_regs *regs)
+{
+ if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
+ return perf_guest_cbs->get_guest_ip();
+
+ return instruction_pointer(regs);
+}
+
+unsigned long perf_misc_flags(struct pt_regs *regs)
+{
+ int misc = 0;
+
+ if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
+ if (perf_guest_cbs->is_user_mode())
+ misc |= PERF_RECORD_MISC_GUEST_USER;
+ else
+ misc |= PERF_RECORD_MISC_GUEST_KERNEL;
+ } else {
+ if (user_mode(regs))
+ misc |= PERF_RECORD_MISC_USER;
+ else
+ misc |= PERF_RECORD_MISC_KERNEL;
+ }
+
+ return misc;
+}