Re: [PATCH 1/3] powerpc/xmon: Check for HV mode when dumping XIVE info from OPAL

On 15/08/2019 09:30, Jordan Niethe wrote:

On Wed, 2019-08-14 at 17:47 +0200, Cédric Le Goater wrote:

quoted

Currently, the xmon 'dx' command calls OPAL to dump the XIVE state in
the OPAL logs and also outputs some of the fields of the internal
XIVE
structures in Linux. The OPAL calls can only be done on baremetal
(PowerNV) and they crash a pseries machine. Fix by checking the
hypervisor feature of the CPU.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/powerpc/xmon/xmon.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 14e56c25879f..25d4adccf750 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c

@@ -2534,13 +2534,16 @@ static void dump_pacas(void)
 static void dump_one_xive(int cpu)
 {
 	unsigned int hwid = get_hard_smp_processor_id(cpu);
-
-	opal_xive_dump(XIVE_DUMP_TM_HYP, hwid);
-	opal_xive_dump(XIVE_DUMP_TM_POOL, hwid);
-	opal_xive_dump(XIVE_DUMP_TM_OS, hwid);
-	opal_xive_dump(XIVE_DUMP_TM_USER, hwid);
-	opal_xive_dump(XIVE_DUMP_VP, hwid);
-	opal_xive_dump(XIVE_DUMP_EMU_STATE, hwid);
+	bool hv = cpu_has_feature(CPU_FTR_HVMODE);
+
+	if (hv) {
+		opal_xive_dump(XIVE_DUMP_TM_HYP, hwid);
+		opal_xive_dump(XIVE_DUMP_TM_POOL, hwid);
+		opal_xive_dump(XIVE_DUMP_TM_OS, hwid);
+		opal_xive_dump(XIVE_DUMP_TM_USER, hwid);
+		opal_xive_dump(XIVE_DUMP_VP, hwid);
+		opal_xive_dump(XIVE_DUMP_EMU_STATE, hwid);
+	}
 
 	if (setjmp(bus_error_jmp) != 0) {
 		catch_memory_errors = 0;

dump_one_xive() / other xive functions are guarded by #ifdef
CONFIG_PPC_POWERNV in xmon.c aren't they? With this series would it be
that these guards can be removed?

One could compile without CONFIG_PPC_POWERNV but we would still want 
these commands to be available for pseries. I missed that.

I think we should move the opal_xive_dump calls to some other command, 
dxo for 'dump_xive_opal' may be, as they only output in the OPAL logs.

This needs some rework.

Thanks,

C.