| Message ID | 20240820065623.1140399-2-hari55@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: s390: selftests: Add regression tests for CPU subfunctions | expand |
On Tue Aug 20, 2024 at 8:48 AM CEST, Hariharan Mari wrote: > Introduce new regression tests to verify the ASM inline block in the SORTL > and DFLTCC CPU subfunctions for the s390x architecture. These tests ensure > that future changes to the ASM code are properly validated. > > The test procedure: > > 1. Create a VM and request the KVM_S390_VM_CPU_MACHINE_SUBFUNC attribute > from the KVM_S390_VM_CPU_MODEL group for this VM. This SUBFUNC attribute > contains the results of all CPU subfunction instructions. > 2. For each tested subfunction (SORTL and DFLTCC), execute the > corresponding ASM instruction and capture the result array. > 3. Perform a memory comparison between the results stored in the SUBFUNC > attribute (obtained in step 1) and the ASM instruction results (obtained > in step 2) for each tested subfunction. > > This process ensures that the KVM implementation accurately reflects the > behavior of the actual CPU instructions for the tested subfunctions. > > Suggested-by: Janosch Frank <frankja@linux.ibm.com> > Signed-off-by: Hariharan Mari <hari55@linux.ibm.com> > Reviewed-by: Janosch Frank <frankja@linux.ibm.com> LGTM Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> > --- > tools/testing/selftests/kvm/Makefile | 1 + > .../selftests/kvm/include/s390x/facility.h | 50 ++++++++ > .../kvm/s390x/cpumodel_subfuncs_test.c | 115 ++++++++++++++++++ > 3 files changed, 166 insertions(+) > create mode 100644 tools/testing/selftests/kvm/include/s390x/facility.h > create mode 100644 tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c [...]
On Tue, 20 Aug 2024 08:48:33 +0200 Hariharan Mari <hari55@linux.ibm.com> wrote: > Introduce new regression tests to verify the ASM inline block in the SORTL > and DFLTCC CPU subfunctions for the s390x architecture. These tests ensure > that future changes to the ASM code are properly validated. > > The test procedure: > > 1. Create a VM and request the KVM_S390_VM_CPU_MACHINE_SUBFUNC attribute > from the KVM_S390_VM_CPU_MODEL group for this VM. This SUBFUNC attribute > contains the results of all CPU subfunction instructions. > 2. For each tested subfunction (SORTL and DFLTCC), execute the > corresponding ASM instruction and capture the result array. > 3. Perform a memory comparison between the results stored in the SUBFUNC > attribute (obtained in step 1) and the ASM instruction results (obtained > in step 2) for each tested subfunction. > > This process ensures that the KVM implementation accurately reflects the > behavior of the actual CPU instructions for the tested subfunctions. > > Suggested-by: Janosch Frank <frankja@linux.ibm.com> > Signed-off-by: Hariharan Mari <hari55@linux.ibm.com> > Reviewed-by: Janosch Frank <frankja@linux.ibm.com> > --- > tools/testing/selftests/kvm/Makefile | 1 + > .../selftests/kvm/include/s390x/facility.h | 50 ++++++++ > .../kvm/s390x/cpumodel_subfuncs_test.c | 115 ++++++++++++++++++ > 3 files changed, 166 insertions(+) > create mode 100644 tools/testing/selftests/kvm/include/s390x/facility.h > create mode 100644 tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c > > diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile > index ac280dcba996..9f418c594b55 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -183,6 +183,7 @@ TEST_GEN_PROGS_s390x += s390x/sync_regs_test > TEST_GEN_PROGS_s390x += s390x/tprot > TEST_GEN_PROGS_s390x += s390x/cmma_test > TEST_GEN_PROGS_s390x += s390x/debug_test > +TEST_GEN_PROGS_s390x += s390x/cpumodel_subfuncs_test > TEST_GEN_PROGS_s390x += s390x/shared_zeropage_test > TEST_GEN_PROGS_s390x += demand_paging_test > TEST_GEN_PROGS_s390x += dirty_log_test > diff --git a/tools/testing/selftests/kvm/include/s390x/facility.h b/tools/testing/selftests/kvm/include/s390x/facility.h > new file mode 100644 > index 000000000000..65eef9a722ba > --- /dev/null > +++ b/tools/testing/selftests/kvm/include/s390x/facility.h > @@ -0,0 +1,50 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright IBM Corp. 2024 > + * > + * Authors: > + * Hariharan Mari <hari55@linux.ibm.com> > + * > + * Get the facility bits with the STFLE instruction > + */ > + > +#ifndef SELFTEST_KVM_FACILITY_H > +#define SELFTEST_KVM_FACILITY_H > + > +#include <linux/bitops.h> > + > +#define NB_STFL_DOUBLEWORDS 32 /* alt_stfle_fac_list[16] + stfle_fac_list[16] */ in general it would be better if the comment is before the variable or define > + > +uint64_t stfl_doublewords[NB_STFL_DOUBLEWORDS]; > +bool stfle_flag; I'm not very happy of global variables defined in headers; as we discussed offline, there are several possible solutions: * just make them static * put them in a separate .c in lib/s390x/ * do not use them at all, and simply call stfle every time and probably there are also more solutions I did not think of > + > +static inline bool test_bit_inv(unsigned long nr, > + const unsigned long *ptr) if I'm not mistaken, the column limit is 100 also for the selftests; please fix that throughout the series, it will be more readable > +{ > + return test_bit(nr ^ (BITS_PER_LONG - 1), ptr); > +} > + > +static inline void stfle(uint64_t *fac, unsigned int nb_doublewords) > +{ > + register unsigned long r0 asm("0") = nb_doublewords - 1; > + > + asm volatile(" .insn s,0xb2b00000,0(%1)\n" > + : "+d" (r0) > + : "a" (fac) > + : "memory", "cc"); > +} > + > +static inline void setup_facilities(void) > +{ > + stfle(stfl_doublewords, NB_STFL_DOUBLEWORDS); > + stfle_flag = true; > +} > + > +static inline bool test_facility(int nr) > +{ > + if (!stfle_flag) > + setup_facilities(); > + return test_bit_inv(nr, stfl_doublewords); > +} > + > +#endif > diff --git a/tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c b/tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c > new file mode 100644 > index 000000000000..ea03ce2010bb > --- /dev/null > +++ b/tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c > @@ -0,0 +1,115 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright IBM Corp. 2024 > + * > + * Authors: > + * Hariharan Mari <hari55@linux.ibm.com> > + * > + * The tests compare the result of the KVM ioctl for obtaining CPU subfunction > + * data with those from an ASM block performing the same CPU subfunction. > + * Currently KVM doesn't mask instruction query data reported via the CPU Model, > + * allowing us to directly compare it with the data acquired through executing > + * the queries in the test. > + */ > + > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <sys/ioctl.h> > +#include "facility.h" > + > +#include "kvm_util.h" > + > +/** > + * Query available CPU subfunctions > + */ > +struct kvm_s390_vm_cpu_subfunc cpu_subfunc; > + > +static void get_cpu_machine_subfuntions(struct kvm_vm *vm, > + struct kvm_s390_vm_cpu_subfunc > + *cpu_subfunc) here in particular you can see how ugly it looks with 80 columns :) > +{ > + int r; > + > + r = __kvm_device_attr_get(vm->fd, KVM_S390_VM_CPU_MODEL, > + KVM_S390_VM_CPU_MACHINE_SUBFUNC, cpu_subfunc); > + > + TEST_ASSERT(!r, "Get cpu subfunctions failed r=%d errno=%d", r, errno); > +} > + > +/* > + * Testing Sort Lists (SORTL) CPU subfunction's ASM block > + */ > +static void test_sortl_asm_block(u8 (*query)[32]) > +{ > + asm volatile(" lghi 0,0\n" > + " la 1,%[query]\n" > + " .insn rre,0xb9380000,2,4\n" > + : [query] "=R" (*query) > + : > + : "cc", "0", "1"); > +} > + > +/* > + * Testing Deflate Conversion Call (DFLTCC) CPU subfunction's ASM block > + */ there is no need to use multiline comments for a single line, unless you want to use proper kdoc tags (which is definitely overkill for a selftest) > +static void test_dfltcc_asm_block(u8 (*query)[32]) > +{ > + asm volatile(" lghi 0,0\n" > + " la 1,%[query]\n" > + " .insn rrf,0xb9390000,2,4,6,0\n" > + : [query] "=R" (*query) > + : > + : "cc", "0", "1"); > +} > + > +typedef void (*testfunc_t)(u8 (*array)[]); > + > +struct testdef { > + const char *subfunc_name; > + u8 *subfunc_array; > + size_t array_size; > + testfunc_t test; > + int facility_bit; > +} testlist[] = { > + /* SORTL - Facility bit 150 */ > + { "SORTL", cpu_subfunc.sortl, sizeof(cpu_subfunc.sortl), > + test_sortl_asm_block, 150 }, here as well, I think it fits in one line > + /* DFLTCC - Facility bit 151 */ > + { "DFLTCC", cpu_subfunc.dfltcc, sizeof(cpu_subfunc.dfltcc), > + test_dfltcc_asm_block, 151 }, > +}; > + > +int main(int argc, char *argv[]) > +{ > + struct kvm_vm *vm; > + int idx; > + > + ksft_print_header(); > + > + vm = vm_create(1); > + > + memset(&cpu_subfunc, 0, sizeof(cpu_subfunc)); > + get_cpu_machine_subfuntions(vm, &cpu_subfunc); > + > + ksft_set_plan(ARRAY_SIZE(testlist)); > + for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) { > + if (test_facility(testlist[idx].facility_bit)) { > + u8 *array = malloc(testlist[idx].array_size); > + > + testlist[idx].test((u8 (*)[testlist[idx].array_size])array); > + > + TEST_ASSERT_EQ(memcmp(testlist[idx].subfunc_array, > + array, testlist[idx].array_size), 0); > + > + ksft_test_result_pass("%s\n", testlist[idx].subfunc_name); > + free(array); > + } else { > + ksft_test_result_skip("%s feature is not avaialable\n", > + testlist[idx].subfunc_name); > + } > + } > + > + kvm_vm_free(vm); > + ksft_finished(); > +}
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index ac280dcba996..9f418c594b55 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -183,6 +183,7 @@ TEST_GEN_PROGS_s390x += s390x/sync_regs_test TEST_GEN_PROGS_s390x += s390x/tprot TEST_GEN_PROGS_s390x += s390x/cmma_test TEST_GEN_PROGS_s390x += s390x/debug_test +TEST_GEN_PROGS_s390x += s390x/cpumodel_subfuncs_test TEST_GEN_PROGS_s390x += s390x/shared_zeropage_test TEST_GEN_PROGS_s390x += demand_paging_test TEST_GEN_PROGS_s390x += dirty_log_test diff --git a/tools/testing/selftests/kvm/include/s390x/facility.h b/tools/testing/selftests/kvm/include/s390x/facility.h new file mode 100644 index 000000000000..65eef9a722ba --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/facility.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright IBM Corp. 2024 + * + * Authors: + * Hariharan Mari <hari55@linux.ibm.com> + * + * Get the facility bits with the STFLE instruction + */ + +#ifndef SELFTEST_KVM_FACILITY_H +#define SELFTEST_KVM_FACILITY_H + +#include <linux/bitops.h> + +#define NB_STFL_DOUBLEWORDS 32 /* alt_stfle_fac_list[16] + stfle_fac_list[16] */ + +uint64_t stfl_doublewords[NB_STFL_DOUBLEWORDS]; +bool stfle_flag; + +static inline bool test_bit_inv(unsigned long nr, + const unsigned long *ptr) +{ + return test_bit(nr ^ (BITS_PER_LONG - 1), ptr); +} + +static inline void stfle(uint64_t *fac, unsigned int nb_doublewords) +{ + register unsigned long r0 asm("0") = nb_doublewords - 1; + + asm volatile(" .insn s,0xb2b00000,0(%1)\n" + : "+d" (r0) + : "a" (fac) + : "memory", "cc"); +} + +static inline void setup_facilities(void) +{ + stfle(stfl_doublewords, NB_STFL_DOUBLEWORDS); + stfle_flag = true; +} + +static inline bool test_facility(int nr) +{ + if (!stfle_flag) + setup_facilities(); + return test_bit_inv(nr, stfl_doublewords); +} + +#endif diff --git a/tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c b/tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c new file mode 100644 index 000000000000..ea03ce2010bb --- /dev/null +++ b/tools/testing/selftests/kvm/s390x/cpumodel_subfuncs_test.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright IBM Corp. 2024 + * + * Authors: + * Hariharan Mari <hari55@linux.ibm.com> + * + * The tests compare the result of the KVM ioctl for obtaining CPU subfunction + * data with those from an ASM block performing the same CPU subfunction. + * Currently KVM doesn't mask instruction query data reported via the CPU Model, + * allowing us to directly compare it with the data acquired through executing + * the queries in the test. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include "facility.h" + +#include "kvm_util.h" + +/** + * Query available CPU subfunctions + */ +struct kvm_s390_vm_cpu_subfunc cpu_subfunc; + +static void get_cpu_machine_subfuntions(struct kvm_vm *vm, + struct kvm_s390_vm_cpu_subfunc + *cpu_subfunc) +{ + int r; + + r = __kvm_device_attr_get(vm->fd, KVM_S390_VM_CPU_MODEL, + KVM_S390_VM_CPU_MACHINE_SUBFUNC, cpu_subfunc); + + TEST_ASSERT(!r, "Get cpu subfunctions failed r=%d errno=%d", r, errno); +} + +/* + * Testing Sort Lists (SORTL) CPU subfunction's ASM block + */ +static void test_sortl_asm_block(u8 (*query)[32]) +{ + asm volatile(" lghi 0,0\n" + " la 1,%[query]\n" + " .insn rre,0xb9380000,2,4\n" + : [query] "=R" (*query) + : + : "cc", "0", "1"); +} + +/* + * Testing Deflate Conversion Call (DFLTCC) CPU subfunction's ASM block + */ +static void test_dfltcc_asm_block(u8 (*query)[32]) +{ + asm volatile(" lghi 0,0\n" + " la 1,%[query]\n" + " .insn rrf,0xb9390000,2,4,6,0\n" + : [query] "=R" (*query) + : + : "cc", "0", "1"); +} + +typedef void (*testfunc_t)(u8 (*array)[]); + +struct testdef { + const char *subfunc_name; + u8 *subfunc_array; + size_t array_size; + testfunc_t test; + int facility_bit; +} testlist[] = { + /* SORTL - Facility bit 150 */ + { "SORTL", cpu_subfunc.sortl, sizeof(cpu_subfunc.sortl), + test_sortl_asm_block, 150 }, + /* DFLTCC - Facility bit 151 */ + { "DFLTCC", cpu_subfunc.dfltcc, sizeof(cpu_subfunc.dfltcc), + test_dfltcc_asm_block, 151 }, +}; + +int main(int argc, char *argv[]) +{ + struct kvm_vm *vm; + int idx; + + ksft_print_header(); + + vm = vm_create(1); + + memset(&cpu_subfunc, 0, sizeof(cpu_subfunc)); + get_cpu_machine_subfuntions(vm, &cpu_subfunc); + + ksft_set_plan(ARRAY_SIZE(testlist)); + for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) { + if (test_facility(testlist[idx].facility_bit)) { + u8 *array = malloc(testlist[idx].array_size); + + testlist[idx].test((u8 (*)[testlist[idx].array_size])array); + + TEST_ASSERT_EQ(memcmp(testlist[idx].subfunc_array, + array, testlist[idx].array_size), 0); + + ksft_test_result_pass("%s\n", testlist[idx].subfunc_name); + free(array); + } else { + ksft_test_result_skip("%s feature is not avaialable\n", + testlist[idx].subfunc_name); + } + } + + kvm_vm_free(vm); + ksft_finished(); +}