Re: [kvm-unit-tests PATCH 2/5] powerpc: add test to check invalid instruction trap

[Laurent Vivier <lvivier@redhat.com>]

On 18/03/2016 10:51, Thomas Huth wrote:
> On 16.03.2016 16:13, Laurent Vivier wrote:
>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>> ---
>>  powerpc/Makefile.common |  5 ++++-
>>  powerpc/emulator.c      | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>>  powerpc/unittests.cfg   |  3 +++
>>  3 files changed, 53 insertions(+), 1 deletion(-)
>>  create mode 100644 powerpc/emulator.c
>>
>> diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common
>> index ab2caf6..257e3fb 100644
>> --- a/powerpc/Makefile.common
>> +++ b/powerpc/Makefile.common
>> @@ -7,7 +7,8 @@
>>  tests-common = \
>>  	$(TEST_DIR)/selftest.elf \
>>  	$(TEST_DIR)/spapr_hcall.elf \
>> -	$(TEST_DIR)/rtas.elf
>> +	$(TEST_DIR)/rtas.elf \
>> +	$(TEST_DIR)/emulator.elf
>>  
>>  all: $(TEST_DIR)/boot_rom.bin test_cases
>>  
>> @@ -70,3 +71,5 @@ $(TEST_DIR)/selftest.elf: $(cstart.o) $(reloc.o) $(TEST_DIR)/selftest.o
>>  $(TEST_DIR)/spapr_hcall.elf: $(cstart.o) $(reloc.o) $(TEST_DIR)/spapr_hcall.o
>>  
>>  $(TEST_DIR)/rtas.elf: $(cstart.o) $(reloc.o) $(TEST_DIR)/rtas.o
>> +
>> +$(TEST_DIR)/emulator.elf: $(cstart.o) $(reloc.o) $(TEST_DIR)/emulator.o
>> diff --git a/powerpc/emulator.c b/powerpc/emulator.c
>> new file mode 100644
>> index 0000000..1215c4f
>> --- /dev/null
>> +++ b/powerpc/emulator.c
>> @@ -0,0 +1,46 @@
>> +/*
>> + * Test some powerpc instructions
>> + */
>> +
>> +#include <libcflat.h>
>> +#include <asm/processor.h>
>> +
>> +static int volatile is_invalid;
>> +
>> +static void program_check_handler(struct pt_regs *regs, void *opaque)
>> +{
>> +	int *data = opaque;
>> +
>> +	printf("Detected invalid instruction 0x%016lx: %08x\n",
>> +	       regs->nip, *(uint32_t*)regs->nip);
> 
> Should the test always print this, or is this rather confusing for the
> users? Then it should maybe be commented out by default, I think.

In fact, it was really helpful to debug (for instance with kvm-pr), it's
why I let it. But as I agree with you, I'll remove it.

> 
>> +	*data = 1;
>> +
>> +	regs->nip += 4;
>> +}
>> +
>> +static void test_illegal(void)
>> +{
>> +	report_prefix_push("invalid");
>> +
>> +	is_invalid = 0;
>> +
>> +	asm volatile (".long 0");
>> +
>> +	report("exception", is_invalid);
>> +
>> +	report_prefix_pop();
>> +}
>> +
>> +int main(void)
>> +{
>> +	handle_exception(0x700, program_check_handler, (void *)&is_invalid);
>> +
>> +	report_prefix_push("emulator");
>> +
>> +	test_illegal();
>> +
>> +	report_prefix_pop();
>> +
>> +	return report_summary();
>> +}
>> diff --git a/powerpc/unittests.cfg b/powerpc/unittests.cfg
>> index 02b21c7..ed4fdbe 100644
>> --- a/powerpc/unittests.cfg
>> +++ b/powerpc/unittests.cfg
>> @@ -47,3 +47,6 @@ file = rtas.elf
>>  extra_params = -append "set-time-of-day"
>>  timeout = 5
>>  groups = rtas
>> +
>> +[emulator]
>> +file = emulator.elf
> 
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> 
> BTW: I think you could optionally also check the contents of SRR1 for
> sane values in test_illegal(), in case you want to improve the test a
> little bit.

OK,

Thanks,
Laurent