From 443e802bab16916f9a51a34f2213f4dee6e8762c Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Thu, 12 Dec 2013 17:54:57 +0100 Subject: 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 Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/perf_cpum_sf.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/s390/kernel/perf_cpum_sf.c') diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index 3ab7e67ee2e4..d611facae599 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -840,6 +840,7 @@ static int perf_push_sample(struct perf_event *event, { int overflow; struct pt_regs regs; + struct perf_sf_sde_regs *sde_regs; struct perf_sample_data data; /* Skip samples that are invalid or for which the instruction address @@ -850,7 +851,16 @@ static int perf_push_sample(struct perf_event *event, perf_sample_data_init(&data, 0, event->hw.last_period); + /* Setup pt_regs to look like an CPU-measurement external interrupt + * using the Program Request Alert code. The regs.int_parm_long + * field which is unused contains additional sample-data-entry related + * indicators. + */ memset(®s, 0, sizeof(regs)); + regs.int_code = 0x1407; + regs.int_parm = CPU_MF_INT_SF_PRA; + sde_regs = (struct perf_sf_sde_regs *) ®s.int_parm_long; + regs.psw.addr = sample->ia; if (sample->T) regs.psw.mask |= PSW_MASK_DAT; @@ -873,6 +883,16 @@ static int perf_push_sample(struct perf_event *event, break; } + /* The host-program-parameter (hpp) contains the sie control + * block that is set by sie64a() in entry64.S. Check if hpp + * refers to a valid control block and set sde_regs flags + * accordingly. This would allow to use hpp values for other + * purposes too. + * For now, simply use a non-zero value as guest indicator. + */ + if (sample->hpp) + sde_regs->in_guest = 1; + overflow = 0; if (perf_event_overflow(event, &data, ®s)) { overflow = 1; -- cgit v1.2.3