Re: [kvm-unit-tests PATCH v8 6/6] s390x: SCLP unit test

[David Hildenbrand <david@redhat.com>]

On 22.01.20 11:10, David Hildenbrand wrote:
> On 20.01.20 19:42, Claudio Imbrenda wrote:
>> SCLP unit test. Testing the following:
>>
>> * Correctly ignoring instruction bits that should be ignored
>> * Privileged instruction check
>> * Check for addressing exceptions
>> * Specification exceptions:
>>   - SCCB size less than 8
>>   - SCCB unaligned
>>   - SCCB overlaps prefix or lowcore
>>   - SCCB address higher than 2GB
>> * Return codes for
>>   - Invalid command
>>   - SCCB too short (but at least 8)
>>   - SCCB page boundary violation
>>
>> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> Acked-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  s390x/Makefile      |   1 +
>>  s390x/sclp.c        | 474 ++++++++++++++++++++++++++++++++++++++++++++
>>  s390x/unittests.cfg |   8 +
>>  3 files changed, 483 insertions(+)
>>  create mode 100644 s390x/sclp.c
>>
>> diff --git a/s390x/Makefile b/s390x/Makefile
>> index 3744372..ddb4b48 100644
>> --- a/s390x/Makefile
>> +++ b/s390x/Makefile
>> @@ -16,6 +16,7 @@ tests += $(TEST_DIR)/diag288.elf
>>  tests += $(TEST_DIR)/stsi.elf
>>  tests += $(TEST_DIR)/skrf.elf
>>  tests += $(TEST_DIR)/smp.elf
>> +tests += $(TEST_DIR)/sclp.elf
>>  tests_binary = $(patsubst %.elf,%.bin,$(tests))
>>  
>>  all: directories test_cases test_cases_binary
>> diff --git a/s390x/sclp.c b/s390x/sclp.c
>> new file mode 100644
>> index 0000000..215347e
>> --- /dev/null
>> +++ b/s390x/sclp.c
>> @@ -0,0 +1,474 @@
>> +/*
>> + * Service Call tests
>> + *
>> + * Copyright (c) 2019 IBM Corp
>> + *
>> + * Authors:
>> + *  Claudio Imbrenda <imbrenda@linux.ibm.com>
>> + *
>> + * This code is free software; you can redistribute it and/or modify it
>> + * under the terms of the GNU General Public License version 2.
>> + */
>> +
>> +#include <libcflat.h>
>> +#include <asm/page.h>
>> +#include <asm/asm-offsets.h>
>> +#include <asm/interrupt.h>
>> +#include <sclp.h>
>> +
>> +#define PGM_NONE	1
>> +#define PGM_BIT_SPEC	(1ULL << PGM_INT_CODE_SPECIFICATION)
>> +#define PGM_BIT_ADDR	(1ULL << PGM_INT_CODE_ADDRESSING)
>> +#define PGM_BIT_PRIV	(1ULL << PGM_INT_CODE_PRIVILEGED_OPERATION)
>> +#define MKPTR(x) ((void *)(uint64_t)(x))
>> +
>> +#define LC_SIZE (2 * PAGE_SIZE)
>> +
>> +static uint8_t pagebuf[LC_SIZE] __attribute__((aligned(LC_SIZE)));	/* scratch pages used for some tests */
>> +static uint8_t prefix_buf[LC_SIZE] __attribute__((aligned(LC_SIZE)));	/* temporary lowcore for test_sccb_prefix */
>> +static uint8_t sccb_template[PAGE_SIZE];				/* SCCB template to be used */
>> +static uint32_t valid_code;						/* valid command code for READ SCP INFO */
>> +static struct lowcore *lc;
>> +
>> +/**
>> + * Perform one service call, handling exceptions and interrupts.
>> + */
>> +static int sclp_service_call_test(unsigned int command, void *sccb)
>> +{
>> +	int cc;
>> +
>> +	sclp_mark_busy();
>> +	sclp_setup_int();
>> +	cc = servc(command, __pa(sccb));
>> +	if (lc->pgm_int_code) {
>> +		sclp_handle_ext();
>> +		return 0;
>> +	}
>> +	if (!cc)
>> +		sclp_wait_busy();
>> +	return cc;
>> +}
>> +
>> +/**
>> + * Perform one test at the given address, optionally using the SCCB template,
>> + * checking for the expected program interrupts and return codes.
>> + *
>> + * The parameter buf_len indicates the number of bytes of the template that
>> + * should be copied to the test address, and should be 0 when the test
>> + * address is invalid, in which case nothing is copied.
>> + *
>> + * The template is used to simplify tests where the same buffer content is
>> + * used many times in a row, at different addresses.
>> + *
>> + * Returns true in case of success or false in case of failure
>> + */
>> +static bool test_one_sccb(uint32_t cmd, uint8_t *addr, uint16_t buf_len, uint64_t exp_pgm, uint16_t exp_rc)
>> +{
>> +	SCCBHeader *h = (SCCBHeader *)addr;
>> +	int res, pgm;
>> +
>> +	/* Copy the template to the test address if needed */
>> +	if (buf_len)
>> +		memcpy(addr, sccb_template, buf_len);
>> +	if (exp_pgm != PGM_NONE)
>> +		expect_pgm_int();
>> +	/* perform the actual call */
>> +	res = sclp_service_call_test(cmd, h);
>> +	if (res) {
>> +		report_info("SCLP not ready (command %#x, address %p, cc %d)", cmd, addr, res);
>> +		return false;
>> +	}
>> +	pgm = clear_pgm_int();
>> +	/* Check if the program exception was one of the expected ones */
>> +	if (!((1ULL << pgm) & exp_pgm)) {
>> +		report_info("First failure at addr %p, buf_len %d, cmd %#x, pgm code %d",
>> +				addr, buf_len, cmd, pgm);
>> +		return false;
>> +	}
>> +	/* Check if the response code is the one expected */
>> +	if (exp_rc && exp_rc != h->response_code) {
>> +		report_info("First failure at addr %p, buf_len %d, cmd %#x, resp code %#x",
>> +				addr, buf_len, cmd, h->response_code);
>> +		return false;
>> +	}
>> +	return true;
>> +}
>> +
>> +/**
>> + * Wrapper for test_one_sccb to be used when the template should not be
>> + * copied and the memory address should not be touched.
>> + */
>> +static bool test_one_ro(uint32_t cmd, uint8_t *addr, uint64_t exp_pgm, uint16_t exp_rc)
>> +{
>> +	return test_one_sccb(cmd, addr, 0, exp_pgm, exp_rc);
>> +}
>> +
>> +/**
>> + * Wrapper for test_one_sccb to set up a simple SCCB template.
>> + *
>> + * The parameter sccb_len indicates the value that will be saved in the SCCB
>> + * length field of the SCCB, buf_len indicates the number of bytes of
>> + * template that need to be copied to the actual test address. In many cases
>> + * it's enough to clear/copy the first 8 bytes of the buffer, while the SCCB
>> + * itself can be larger.
>> + *
>> + * Returns true in case of success or false in case of failure
>> + */
>> +static bool test_one_simple(uint32_t cmd, uint8_t *addr, uint16_t sccb_len,
>> +			uint16_t buf_len, uint64_t exp_pgm, uint16_t exp_rc)
>> +{
>> +	memset(sccb_template, 0, sizeof(sccb_template));
>> +	((SCCBHeader *)sccb_template)->length = sccb_len;
>> +	return test_one_sccb(cmd, addr, buf_len, exp_pgm, exp_rc);
> 
> Doing a fresh ./configure + make on RHEL7 gives me
> 
> [linux1@rhkvm01 kvm-unit-tests]$ make
> gcc  -std=gnu99 -ffreestanding -I /home/linux1/git/kvm-unit-tests/lib -I /home/linux1/git/kvm-unit-tests/lib/s390x -I lib -O2 -march=zEC12 -fno-delete-null-pointer-checks -g -MMD -MF s390x/.sclp.d -Wall -Wwrite-strings -Wempty-body -Wuninitialized -Wignored-qualifiers -Werror  -fomit-frame-pointer    -Wno-frame-address   -fno-pic    -Wclobbered  -Wunused-but-set-parameter  -Wmissing-parameter-type  -Wold-style-declaration -Woverride-init -Wmissing-prototypes -Wstrict-prototypes   -c -o s390x/sclp.o s390x/sclp.c
> s390x/sclp.c: In function 'test_one_simple':
> s390x/sclp.c:121:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
>   ((SCCBHeader *)sccb_template)->length = sccb_len;
>   ^
> s390x/sclp.c: At top level:
> cc1: error: unrecognized command line option "-Wno-frame-address" [-Werror]
> cc1: all warnings being treated as errors
> make: *** [s390x/sclp.o] Error 1

The following makes it work:


diff --git a/s390x/sclp.c b/s390x/sclp.c
index c13fa60..0b8117a 100644
--- a/s390x/sclp.c
+++ b/s390x/sclp.c
@@ -117,8 +117,10 @@ static bool test_one_ro(uint32_t cmd, uint8_t *addr, uint64_t exp_pgm, uint16_t
 static bool test_one_simple(uint32_t cmd, uint8_t *addr, uint16_t sccb_len,
                        uint16_t buf_len, uint64_t exp_pgm, uint16_t exp_rc)
 {
+       SCCBHeader *header = (void *)sccb_template;
+
        memset(sccb_template, 0, sizeof(sccb_template));
-       ((SCCBHeader *)sccb_template)->length = sccb_len;
+       header->length = sccb_len;
        return test_one_sccb(cmd, addr, buf_len, exp_pgm, exp_rc);
 }
 

-- 
Thanks,

David / dhildenb