Re: [kvm-unit-tests PATCH 2/2] s390x: add test for SIGP STORE_ADTL_STATUS order

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Fri,  1 Apr 2022 14:33:21 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:

> Add a test for SIGP STORE_ADDITIONAL_STATUS order.
> 
> There are several cases to cover:
> - when neither vector nor guarded-storage facility is available, check
>   the order is rejected.
> - when one of the facilities is there, test the order is rejected and
>   adtl_status is not touched when the target CPU is running or when an
>   invalid CPU address is specified. Also check the order is rejected
>   in case of invalid alignment.
> - when the vector facility is there, write some data to the CPU's
>   vector registers and check we get the right contents.
> - when the guarded-storage facility is there, populate the CPU's
>   guarded-storage registers with some data and again check we get the
>   right contents.
> 
> To make sure we cover all these cases, adjust unittests.cfg to run the
> test with both guarded-storage and vector facility off and on. In TCG, we don't
> have guarded-storage support, so we just run with vector facility off and on.
> 
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
>  lib/s390x/asm/vector.h |  16 ++
>  s390x/Makefile         |   1 +
>  s390x/adtl-status.c    | 411 +++++++++++++++++++++++++++++++++++++++++
>  s390x/unittests.cfg    |  25 +++
>  4 files changed, 453 insertions(+)
>  create mode 100644 lib/s390x/asm/vector.h
>  create mode 100644 s390x/adtl-status.c
> 
> diff --git a/lib/s390x/asm/vector.h b/lib/s390x/asm/vector.h
> new file mode 100644
> index 000000000000..ee48bfa65070
> --- /dev/null
> +++ b/lib/s390x/asm/vector.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Vector facility related defines and functions
> + *
> + * Copyright IBM Corp. 2022
> + *
> + * Authors:
> + *    Nico Boehr <nrb@linux.ibm.com>
> + */
> +#ifndef _ASMS390X_VECTOR_H_
> +#define _ASMS390X_VECTOR_H_
> +
> +#define VEC_REGISTER_NUM 32
> +#define VEC_REGISTER_SIZE 16
> +
> +#endif
> diff --git a/s390x/Makefile b/s390x/Makefile
> index 53b0fe044fe7..867d261622b6 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -26,6 +26,7 @@ tests += $(TEST_DIR)/edat.elf
>  tests += $(TEST_DIR)/mvpg-sie.elf
>  tests += $(TEST_DIR)/spec_ex-sie.elf
>  tests += $(TEST_DIR)/firq.elf
> +tests += $(TEST_DIR)/adtl-status.elf
>  
>  pv-tests += $(TEST_DIR)/pv-diags.elf
>  
> diff --git a/s390x/adtl-status.c b/s390x/adtl-status.c
> new file mode 100644
> index 000000000000..c3ecdbc35a9d
> --- /dev/null
> +++ b/s390x/adtl-status.c
> @@ -0,0 +1,411 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Tests sigp store additional status order
> + *
> + * Copyright IBM Corp. 2022
> + *
> + * Authors:
> + *    Nico Boehr <nrb@linux.ibm.com>
> + */
> +#include <libcflat.h>
> +#include <asm/asm-offsets.h>
> +#include <asm/interrupt.h>
> +#include <asm/facility.h>
> +#include <asm-generic/barrier.h>
> +#include <asm/sigp.h>
> +#include <asm/vector.h>
> +
> +#include <smp.h>
> +#include <gs.h>
> +
> +static int testflag = 0;
> +
> +#define INVALID_CPU_ADDRESS -4711
> +
> +struct mcesa_lc12 {
> +	uint8_t vregs[0x200];		      /* 0x000 */
> +	uint8_t reserved200[0x400 - 0x200];   /* 0x200 */
> +	struct gs_cb gs_cb;                   /* 0x400 */
> +	uint8_t reserved420[0x800 - 0x420];   /* 0x420 */
> +	uint8_t reserved800[0x1000 - 0x800];  /* 0x800 */
> +};
> +
> +static struct mcesa_lc12 adtl_status __attribute__((aligned(4096)));
> +
> +static uint8_t expected_vec_contents[VEC_REGISTER_NUM][VEC_REGISTER_SIZE];
> +
> +static struct gs_cb gs_cb;
> +static struct gs_epl gs_epl;
> +
> +static bool memisset(void *s, int c, size_t n)
> +{
> +	uint8_t *p = s;
> +	size_t i;
> +
> +	for (i = 0; i < n; i++) {
> +		if (p[i] != c) {
> +			return false;
> +		}
> +	}

you don't need the braces here

> +
> +	return true;
> +}
> +
> +static void wait_for_flag(void)
> +{
> +	while (!testflag)
> +		mb();
> +}
> +
> +static void set_flag(int val)
> +{
> +	mb();
> +	testflag = val;
> +	mb();
> +}
> +
> +static void test_func(void)
> +{
> +	set_flag(1);
> +}
> +
> +static bool have_adtl_status(void)
> +{
> +	return test_facility(133) || test_facility(129);
> +}
> +
> +static void test_store_adtl_status(void)
> +{
> +	uint32_t status = -1;
> +	int cc;
> +
> +	report_prefix_push("store additional status");
> +
> +	if (!have_adtl_status()) {
> +		report_skip("no guarded-storage or vector facility installed");
> +		goto out;
> +	}
> +
> +	memset(&adtl_status, 0xff, sizeof(adtl_status));
> +
> +	report_prefix_push("running");
> +	smp_cpu_restart(1);
> +
> +	cc = smp_sigp(1, SIGP_STORE_ADDITIONAL_STATUS,
> +		  (unsigned long)&adtl_status, &status);
> +
> +	report(cc == 1, "CC = 1");
> +	report(status == SIGP_STATUS_INCORRECT_STATE, "status = INCORRECT_STATE");
> +	report(memisset(&adtl_status, 0xff, sizeof(adtl_status)),
> +	       "additional status not touched");
> +
> +	report_prefix_pop();
> +
> +	report_prefix_push("invalid CPU address");
> +
> +	cc = sigp(INVALID_CPU_ADDRESS, SIGP_STORE_ADDITIONAL_STATUS,
> +		  (unsigned long)&adtl_status, &status);
> +	report(cc == 3, "CC = 3");
> +	report(memisset(&adtl_status, 0xff, sizeof(adtl_status)),
> +	       "additional status not touched");
> +
> +	report_prefix_pop();
> +
> +	report_prefix_push("unaligned");
> +	smp_cpu_stop(1);
> +
> +	cc = smp_sigp(1, SIGP_STORE_ADDITIONAL_STATUS,
> +		  (unsigned long)&adtl_status + 256, &status);
> +	report(cc == 1, "CC = 1");
> +	report(status == SIGP_STATUS_INVALID_PARAMETER, "status = INVALID_PARAMETER");
> +	report(memisset(&adtl_status, 0xff, sizeof(adtl_status)),
> +	       "additional status not touched");
> +
> +	report_prefix_pop();
> +
> +out:
> +	report_prefix_pop();
> +}
> +
> +static void test_store_adtl_status_unavail(void)
> +{
> +	uint32_t status = 0;
> +	int cc;
> +
> +	report_prefix_push("store additional status unavailable");
> +
> +	if (have_adtl_status()) {
> +		report_skip("guarded-storage or vector facility installed");
> +		goto out;
> +	}
> +
> +	report_prefix_push("not accepted");
> +	smp_cpu_stop(1);
> +
> +	memset(&adtl_status, 0xff, sizeof(adtl_status));
> +
> +	cc = smp_sigp(1, SIGP_STORE_ADDITIONAL_STATUS,
> +		  (unsigned long)&adtl_status, &status);
> +
> +	report(cc == 1, "CC = 1");
> +	report(status == SIGP_STATUS_INVALID_ORDER,
> +	       "status = INVALID_ORDER");
> +	report(memisset(&adtl_status, 0xff, sizeof(adtl_status)),
> +	       "additional status not touched");
> +
> +	report_prefix_pop();
> +
> +out:
> +	report_prefix_pop();
> +}
> +
> +static void restart_write_vector(void)
> +{
> +	uint8_t *vec_reg;
> +	/* vlm handles at most 16 registers at a time */
> +	uint8_t *vec_reg_16_31 = &expected_vec_contents[16][0];
> +	uint64_t cr0, cr0_mask = ~(1ULL << CTL0_VECTOR);

cr0_mask can be const, and you can use ~BIT_ULL(CTL0_VECTOR)

> +	int one = 1;

one can also be const, although I wonder if this can just become an
constant in the asm statement

> +	int i;
> +
> +	for (i = 0; i < VEC_REGISTER_NUM; i++) {
> +		vec_reg = &expected_vec_contents[i][0];
> +		/* i+1 to avoid zero content */
> +		memset(vec_reg, i + 1, VEC_REGISTER_SIZE);
> +	}
> +
> +	ctl_set_bit(0, CTL0_VECTOR);
> +
> +	asm volatile (
> +		"	.machine z13\n"
> +		/* load vector registers */
> +		"	vlm 0,15, %[vec_reg_0_15]\n"
> +		"	vlm 16,31, %[vec_reg_16_31]\n"
> +		/* turn off vector instructions */
> +		"	stctg 0,0, %[cr0]\n"
> +		"	ng %[cr0_mask], %[cr0]\n"
> +		"	stg %[cr0_mask], %[cr0]\n"
> +		"	lctlg 0,0, %[cr0]\n"
> +		/* inform CPU 0 we are done by setting testflag to 1 */
> +		"	st %[one], %[testflag]\n"
> +		/*
> +		 * infinite loop. function epilogue will restore floating point
> +		 * registers and hence destroy vector register contents
> +		 */
> +		"0:	j 0\n"
> +		: [cr0_mask] "+&d"(cr0_mask)
> +		: [vec_reg_0_15] "Q"(expected_vec_contents),
> +		  [vec_reg_16_31] "Q"(*vec_reg_16_31),
> +		  [cr0] "Q"(cr0),
> +		  [testflag] "T"(testflag),
> +		  [one] "d"(one)
> +		: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8", "v9",
> +		  "v10", "v11", "v12", "v13", "v14", "v15", "v16", "v17", "v18",
> +		  "v19", "v20", "v21", "v22", "v23", "v24", "v25", "v26", "v27",
> +		  "v28", "v29", "v30", "v31", "cc", "memory"
> +	);
> +}
> +
> +static void cpu_write_magic_to_vector_regs(uint16_t cpu_idx)
> +{
> +	struct psw new_psw;
> +
> +	smp_cpu_stop(cpu_idx);
> +
> +	new_psw.mask = extract_psw_mask();
> +	new_psw.addr = (unsigned long)restart_write_vector;
> +
> +	set_flag(0);
> +
> +	smp_cpu_start(cpu_idx, new_psw);
> +
> +	wait_for_flag();
> +}
> +
> +static int adtl_status_check_unmodified_fields_for_lc(unsigned long lc)
> +{
> +	assert (!lc || (lc >= 10 && lc <= 12));
> +
> +	if (lc <= 10 && !memisset(&adtl_status.gs_cb, 0xff, sizeof(adtl_status.gs_cb)))
> +		return false;
> +
> +	if (!memisset(adtl_status.reserved200, 0xff, sizeof(adtl_status.reserved200)))
> +		return false;
> +
> +	if (!memisset(adtl_status.reserved420, 0xff, sizeof(adtl_status.reserved420)))
> +		return false;
> +
> +	if (!memisset(adtl_status.reserved800, 0xff, sizeof(adtl_status.reserved800)))
> +		return false;
> +
> +	return true;
> +}
> +
> +static void __store_adtl_status_vector_lc(unsigned long lc)
> +{
> +	uint32_t status = -1;
> +	struct psw psw;
> +	int cc;
> +
> +	report_prefix_pushf("LC %lu", lc);
> +
> +	if (!test_facility(133) && lc) {
> +		report_skip("not supported, no guarded-storage facility");
> +		goto out;
> +	}
> +
> +	cpu_write_magic_to_vector_regs(1);
> +	smp_cpu_stop(1);
> +
> +	memset(&adtl_status, 0xff, sizeof(adtl_status));
> +
> +	cc = smp_sigp(1, SIGP_STORE_ADDITIONAL_STATUS,
> +		  (unsigned long)&adtl_status | lc, &status);
> +	report(!cc, "CC = 0");
> +
> +	report(!memcmp(adtl_status.vregs,
> +		       expected_vec_contents, sizeof(expected_vec_contents)),
> +	       "additional status contents match");
> +
> +	report(adtl_status_check_unmodified_fields_for_lc(lc),
> +	       "no write outside expected fields");
> +
> +	/*
> +	 * To avoid the floating point/vector registers being cleaned up, we
> +	 * stopped CPU1 right in the middle of a function. Hence the cleanup of
> +	 * the function didn't run yet and the stackpointer is messed up.
> +	 * Destroy and re-initalize the CPU to fix that.
> +	 */
> +	smp_cpu_destroy(1);
> +	psw.mask = extract_psw_mask();
> +	psw.addr = (unsigned long)test_func;
> +	smp_cpu_setup(1, psw);
> +
> +out:
> +	report_prefix_pop();
> +}
> +
> +static void test_store_adtl_status_vector(void)
> +{
> +	report_prefix_push("store additional status vector");
> +
> +	if (!test_facility(129)) {
> +		report_skip("vector facility not installed");
> +		goto out;
> +	}
> +
> +	__store_adtl_status_vector_lc(0);
> +	__store_adtl_status_vector_lc(10);
> +	__store_adtl_status_vector_lc(11);
> +	__store_adtl_status_vector_lc(12);
> +
> +out:
> +	report_prefix_pop();
> +}
> +
> +static void restart_write_gs_regs(void)
> +{
> +	const unsigned long gs_area = 0x2000000;
> +	const unsigned long gsc = 25; /* align = 32 M, section size = 512K */
> +
> +	ctl_set_bit(2, CTL2_GUARDED_STORAGE);
> +
> +	gs_cb.gsd = gs_area | gsc;
> +	gs_cb.gssm = 0xfeedc0ffe;
> +	gs_cb.gs_epl_a = (uint64_t) &gs_epl;
> +
> +	load_gs_cb(&gs_cb);
> +
> +	set_flag(1);
> +
> +	ctl_clear_bit(2, CTL2_GUARDED_STORAGE);
> +
> +	/*
> +	 * Safe to return here. r14 will point to the endless loop in
> +	 * smp_cpu_setup_state.
> +	 */
> +}
> +
> +static void cpu_write_to_gs_regs(uint16_t cpu_idx)
> +{
> +	struct psw new_psw;
> +
> +	smp_cpu_stop(cpu_idx);
> +
> +	new_psw.mask = extract_psw_mask();
> +	new_psw.addr = (unsigned long)restart_write_gs_regs;
> +
> +	set_flag(0);
> +
> +	smp_cpu_start(cpu_idx, new_psw);
> +
> +	wait_for_flag();
> +}
> +
> +static void __store_adtl_status_gs(unsigned long lc)
> +{
> +	uint32_t status = 0;
> +	int cc;
> +
> +	report_prefix_pushf("LC %lu", lc);
> +
> +	cpu_write_to_gs_regs(1);
> +	smp_cpu_stop(1);
> +
> +	memset(&adtl_status, 0xff, sizeof(adtl_status));
> +
> +	cc = smp_sigp(1, SIGP_STORE_ADDITIONAL_STATUS,
> +		  (unsigned long)&adtl_status | lc, &status);
> +	report(!cc, "CC = 0");
> +
> +	report(!memcmp(&adtl_status.gs_cb, &gs_cb, sizeof(gs_cb)),
> +	       "additional status contents match");
> +
> +	report(adtl_status_check_unmodified_fields_for_lc(lc),
> +	       "no write outside expected fields");
> +
> +	report_prefix_pop();
> +}
> +
> +static void test_store_adtl_status_gs(void)
> +{
> +	report_prefix_push("store additional status guarded-storage");
> +
> +	if (!test_facility(133)) {
> +		report_skip("guarded-storage facility not installed");
> +		goto out;
> +	}
> +
> +	__store_adtl_status_gs(11);
> +	__store_adtl_status_gs(12);
> +
> +out:
> +	report_prefix_pop();
> +}
> +
> +int main(void)
> +{
> +	struct psw psw;
> +	report_prefix_push("adtl_status");
> +
> +	if (smp_query_num_cpus() == 1) {
> +		report_skip("need at least 2 cpus for this test");
> +		goto done;
> +	}
> +
> +	/* Setting up the cpu to give it a stack and lowcore */
> +	psw.mask = extract_psw_mask();
> +	psw.addr = (unsigned long)test_func;
> +	smp_cpu_setup(1, psw);
> +	smp_cpu_stop(1);
> +
> +	test_store_adtl_status_unavail();
> +	test_store_adtl_status_vector();
> +	test_store_adtl_status_gs();
> +	test_store_adtl_status();
> +	smp_cpu_destroy(1);
> +
> +done:
> +	report_prefix_pop();
> +	return report_summary();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index 1600e714c8b9..2159ba679519 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -136,3 +136,28 @@ file = firq.elf
>  timeout = 20
>  extra_params = -smp 1,maxcpus=3 -cpu qemu -device qemu-s390x-cpu,core-id=2 -device qemu-s390x-cpu,core-id=1
>  accel = tcg
> +
> +[adtl-status-kvm]
> +file = adtl-status.elf
> +smp = 2
> +accel = kvm
> +extra_params = -cpu host,gs=on,vx=on
> +
> +[adtl-status-no-vec-no-gs-kvm]
> +file = adtl-status.elf
> +smp = 2
> +accel = kvm
> +extra_params = -cpu host,gs=off,vx=off
> +
> +[adtl-status-tcg]
> +file = adtl-status.elf
> +smp = 2
> +accel = tcg
> +# no guarded-storage support in tcg
> +extra_params = -cpu qemu,vx=on
> +
> +[adtl-status-no-vec-no-gs-tcg]
> +file = adtl-status.elf
> +smp = 2
> +accel = tcg
> +extra_params = -cpu qemu,gs=off,vx=off