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

["Cédric Le Goater" <clg@kaod.org>]

On 15/08/2019 10:15, Cédric Le Goater wrote:
> On 15/08/2019 09:30, Jordan Niethe wrote:
>> On Wed, 2019-08-14 at 17:47 +0200, Cédric Le Goater wrote:
>>> 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();