From f69ffc5d3db8f1f03fd6d1df5930f9a1fbd787b6 Mon Sep 17 00:00:00 2001
From: Prarit Bhargava <prarit@redhat.com>
Date: Mon, 8 Oct 2018 11:06:19 -0400
Subject: [PATCH] cpupower: Fix coredump on VMWare
Git-commit: f69ffc5d3db8f1f03fd6d1df5930f9a1fbd787b6
Patch-mainline: v4.20-rc1
References: bsc#1051510
cpupower crashes on VMWare guests. The guests have the AMD PStateDef MSR
(0xC0010064 + state number) set to zero. As a result fid and did are zero
and the crash occurs because of a divide by zero (cof = fid/did). This
can be prevented by checking the enable bit in the PStateDef MSR before
calculating cof. By doing this the value of pstate[i] remains zero and
the value can be tested before displaying the active Pstates.
Check the enable bit in the PstateDef register for all supported families
and only print out enabled Pstates.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
tools/power/cpupower/utils/cpufreq-info.c | 2 ++
tools/power/cpupower/utils/helpers/amd.c | 5 +++++
2 files changed, 7 insertions(+)
diff --git a/tools/power/cpupower/utils/cpufreq-info.c b/tools/power/cpupower/utils/cpufreq-info.c
index df43cd45d810..ccd08dd00996 100644
--- a/tools/power/cpupower/utils/cpufreq-info.c
+++ b/tools/power/cpupower/utils/cpufreq-info.c
@@ -200,6 +200,8 @@ static int get_boost_mode(unsigned int cpu)
printf(_(" Boost States: %d\n"), b_states);
printf(_(" Total States: %d\n"), pstate_no);
for (i = 0; i < pstate_no; i++) {
+ if (!pstates[i])
+ continue;
if (i < b_states)
printf(_(" Pstate-Pb%d: %luMHz (boost state)"
"\n"), i, pstates[i]);
diff --git a/tools/power/cpupower/utils/helpers/amd.c b/tools/power/cpupower/utils/helpers/amd.c
index eed31b27909b..9607ada5b29a 100644
--- a/tools/power/cpupower/utils/helpers/amd.c
+++ b/tools/power/cpupower/utils/helpers/amd.c
@@ -119,6 +119,11 @@ int decode_pstates(unsigned int cpu, unsigned int cpu_family,
}
if (read_msr(cpu, MSR_AMD_PSTATE + i, &pstate.val))
return -1;
+ if ((cpu_family == 0x17) && (!pstate.fam17h_bits.en))
+ continue;
+ else if (!pstate.bits.en)
+ continue;
+
pstates[i] = get_cof(cpu_family, pstate);
}
*no = i;
--
2.16.4