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

On 15/08/2019 10:15, Cédric Le Goater wrote:

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

quoted

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.

The changes below should be enough to activate support for the xive 
commands on pseries and powernv. The patch can come as a follow up.

Cheers,

C. 

--- linux.git.orig/arch/powerpc/xmon/xmon.c
+++ linux.git/arch/powerpc/xmon/xmon.c

@@ -238,7 +238,7 @@ Commands:\n\
   dt	dump the tracing buffers (uses printk)\n\
   dtc	dump the tracing buffers for current CPU (uses printk)\n\
 "
-#ifdef CONFIG_PPC_POWERNV
+#ifdef CONFIG_PPC_BOOK3S_64
 "  dx#   dump xive on CPU #\n\
   dxi#  dump xive irq state #\n\
   dxa   dump xive on all CPUs\n"

@@ -2530,7 +2530,7 @@ static void dump_pacas(void)
 }
 #endif
 
-#ifdef CONFIG_PPC_POWERNV
+#ifdef CONFIG_PPC_BOOK3S_64
 static void dump_one_xive(int cpu)
 {
 	unsigned int hwid = get_hard_smp_processor_id(cpu);

@@ -2632,7 +2632,7 @@ static void dump_xives(void)
 	else
 		dump_one_xive(xmon_owner);
 }
-#endif /* CONFIG_PPC_POWERNV */
+#endif /* CONFIG_PPC_BOOK3S_64 */
 
 static void dump_by_size(unsigned long addr, long count, int size)
 {

@@ -2682,7 +2682,7 @@ dump(void)
 		return;
 	}
 #endif
-#ifdef CONFIG_PPC_POWERNV
+#ifdef CONFIG_PPC_BOOK3S_64
 	if (c == 'x') {
 		xmon_start_pagination();
 		dump_xives();