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authorHendrik Brueckner <brueckner@linux.vnet.ibm.com>2013-12-12 20:54:57 +0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-12-16 17:37:59 +0400
commit443e802bab16916f9a51a34f2213f4dee6e8762c (patch)
tree8481d35917b96ad1dfee837e52ad804e3459e018 /arch/s390/kernel/perf_event.c
parent443d4beb823d4dccaaf964b59df9dd38b4d6aae7 (diff)
downloadlinux-443e802bab16916f9a51a34f2213f4dee6e8762c.tar.xz
s390/cpum_sf: Detect KVM guest samples
The host-program-parameter (hpp) value of basic sample-data-entries designates a SIE control block that is set by the LPP instruction in sie64a(). Non-zero values indicate guest samples, a value of zero indicates a host sample. For perf samples, host and guest samples are distinguished using particular PERF_MISC_* flags. The perf layer calls perf_misc_flags() to set the flags based on the pt_regs content. For each sample-data-entry, the cpum_sf PMU creates a pt_regs structure with the sample-data information. An additional flag structure is added to easily distinguish between host and guest samples. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/perf_event.c')
-rw-r--r--arch/s390/kernel/perf_event.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
index 3bd2bf030ad4..60a68261d091 100644
--- a/arch/s390/kernel/perf_event.c
+++ b/arch/s390/kernel/perf_event.c
@@ -1,7 +1,7 @@
/*
* Performance event support for s390x
*
- * Copyright IBM Corp. 2012
+ * Copyright IBM Corp. 2012, 2013
* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
@@ -89,8 +89,31 @@ static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
: PERF_RECORD_MISC_GUEST_KERNEL;
}
+static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
+{
+ struct perf_sf_sde_regs *sde_regs;
+ unsigned long flags;
+
+ sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
+ if (sde_regs->in_guest)
+ flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
+ : PERF_RECORD_MISC_GUEST_KERNEL;
+ else
+ flags = user_mode(regs) ? PERF_RECORD_MISC_USER
+ : PERF_RECORD_MISC_KERNEL;
+ return flags;
+}
+
unsigned long perf_misc_flags(struct pt_regs *regs)
{
+ /* Check if the cpum_sf PMU has created the pt_regs structure.
+ * In this case, perf misc flags can be easily extracted. Otherwise,
+ * do regular checks on the pt_regs content.
+ */
+ if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
+ if (!regs->gprs[15])
+ return perf_misc_flags_sf(regs);
+
if (is_in_guest(regs))
return perf_misc_guest_flags(regs);