This test allows to test the various storage key handling functions. Signed-off-by: Claudio Imbrenda --- tools/testing/selftests/kvm/Makefile.kvm | 1 + tools/testing/selftests/kvm/s390/keyop.c | 299 +++++++++++++++++++++++ 2 files changed, 300 insertions(+) create mode 100644 tools/testing/selftests/kvm/s390/keyop.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index ba5c2b643efa..2e4774666723 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -199,6 +199,7 @@ TEST_GEN_PROGS_s390 += s390/cpumodel_subfuncs_test TEST_GEN_PROGS_s390 += s390/shared_zeropage_test TEST_GEN_PROGS_s390 += s390/ucontrol_test TEST_GEN_PROGS_s390 += s390/user_operexec +TEST_GEN_PROGS_s390 += s390/keyop TEST_GEN_PROGS_s390 += rseq_test TEST_GEN_PROGS_riscv = $(TEST_GEN_PROGS_COMMON) diff --git a/tools/testing/selftests/kvm/s390/keyop.c b/tools/testing/selftests/kvm/s390/keyop.c new file mode 100644 index 000000000000..c7805e87d12c --- /dev/null +++ b/tools/testing/selftests/kvm/s390/keyop.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Test for s390x KVM_S390_KEYOP + * + * Copyright IBM Corp. 2026 + * + * Authors: + * Claudio Imbrenda + */ +#include +#include +#include +#include + +#include + +#include "test_util.h" +#include "kvm_util.h" +#include "kselftest.h" +#include "processor.h" + +#define BUF_PAGES 128UL +#define GUEST_PAGES 256UL + +#define BUF_START_GFN (GUEST_PAGES - BUF_PAGES) +#define BUF_START_ADDR (BUF_START_GFN << PAGE_SHIFT) + +#define KEY_BITS_ACC 0xf0 +#define KEY_BIT_F 0x08 +#define KEY_BIT_R 0x04 +#define KEY_BIT_C 0x02 + +#define KEY_BITS_RC (KEY_BIT_R | KEY_BIT_C) +#define KEY_BITS_ALL (KEY_BITS_ACC | KEY_BIT_F | KEY_BITS_RC) + +static unsigned char tmp[BUF_PAGES]; +static unsigned char old[BUF_PAGES]; +static unsigned char expected[BUF_PAGES]; + +static int _get_skeys(struct kvm_vcpu *vcpu, unsigned char skeys[]) +{ + struct kvm_s390_skeys skeys_ioctl = { + .start_gfn = BUF_START_GFN, + .count = BUF_PAGES, + .skeydata_addr = (unsigned long)skeys, + }; + + return __vm_ioctl(vcpu->vm, KVM_S390_GET_SKEYS, &skeys_ioctl); +} + +static void get_skeys(struct kvm_vcpu *vcpu, unsigned char skeys[]) +{ + int r = _get_skeys(vcpu, skeys); + + TEST_ASSERT(!r, "Failed to get storage keys, r=%d", r); +} + +static void set_skeys(struct kvm_vcpu *vcpu, unsigned char skeys[]) +{ + struct kvm_s390_skeys skeys_ioctl = { + .start_gfn = BUF_START_GFN, + .count = BUF_PAGES, + .skeydata_addr = (unsigned long)skeys, + }; + int r; + + r = __vm_ioctl(vcpu->vm, KVM_S390_SET_SKEYS, &skeys_ioctl); + TEST_ASSERT(!r, "Failed to set storage keys, r=%d", r); +} + +static int do_keyop(struct kvm_vcpu *vcpu, int op, unsigned long page_idx, unsigned char skey) +{ + struct kvm_s390_keyop keyop = { + .guest_addr = BUF_START_ADDR + page_idx * PAGE_SIZE, + .key = skey, + .operation = op, + }; + int r; + + r = __vm_ioctl(vcpu->vm, KVM_S390_KEYOP, &keyop); + TEST_ASSERT(!r, "Failed to perform keyop, r=%d", r); + TEST_ASSERT((keyop.key & 1) == 0, + "Last bit of key is 1, should be 0! page %lu, new key=%#x, old key=%#x", + page_idx, skey, keyop.key); + + return keyop.key; +} + +static void fault_in_buffer(struct kvm_vcpu *vcpu, int where, int cur_loc) +{ + unsigned long i; + int r; + + if (where != cur_loc) + return; + + for (i = 0; i < BUF_PAGES; i++) { + r = ioctl(vcpu->fd, KVM_S390_VCPU_FAULT, BUF_START_ADDR + i * PAGE_SIZE); + TEST_ASSERT(!r, "Faulting in buffer page %lu, r=%d", i, r); + } +} + +static inline void set_pattern(unsigned char skeys[]) +{ + int i; + + for (i = 0; i < BUF_PAGES; i++) + skeys[i] = i << 1; +} + +static void dump_sk(const unsigned char skeys[], const char *descr) +{ + int i, j; + + fprintf(stderr, "# %s:\n", descr); + for (i = 0; i < BUF_PAGES; i += 32) { + fprintf(stderr, "# %3d: ", i); + for (j = 0; j < 32; j++) + fprintf(stderr, "%02x ", skeys[i + j]); + fprintf(stderr, "\n"); + } +} + +static inline void compare(const unsigned char what[], const unsigned char expected[], + const char *descr, int fault_in_loc) +{ + int i; + + for (i = 0; i < BUF_PAGES; i++) { + if (expected[i] != what[i]) { + dump_sk(expected, "Expected"); + dump_sk(what, "Got"); + } + TEST_ASSERT(expected[i] == what[i], + "%s! fault-in location %d, page %d, expected %#x, got %#x", + descr, fault_in_loc, i, expected[i], what[i]); + } +} + +static inline void clear_all(void) +{ + memset(tmp, 0, BUF_PAGES); + memset(old, 0, BUF_PAGES); + memset(expected, 0, BUF_PAGES); +} + +static void test_init(struct kvm_vcpu *vcpu, int fault_in) +{ + /* Set all storage keys to zero */ + fault_in_buffer(vcpu, fault_in, 1); + set_skeys(vcpu, expected); + + fault_in_buffer(vcpu, fault_in, 2); + get_skeys(vcpu, tmp); + compare(tmp, expected, "Setting keys not zero", fault_in); + + /* Set storage keys to a sequential pattern */ + fault_in_buffer(vcpu, fault_in, 3); + set_pattern(expected); + set_skeys(vcpu, expected); + + fault_in_buffer(vcpu, fault_in, 4); + get_skeys(vcpu, tmp); + compare(tmp, expected, "Setting storage keys failed", fault_in); +} + +static void test_rrbe(struct kvm_vcpu *vcpu, int fault_in) +{ + unsigned char k; + int i; + + /* Set storage keys to a sequential pattern */ + fault_in_buffer(vcpu, fault_in, 1); + set_pattern(expected); + set_skeys(vcpu, expected); + + /* Call the RRBE KEYOP ioctl on each page and verify the result */ + fault_in_buffer(vcpu, fault_in, 2); + for (i = 0; i < BUF_PAGES; i++) { + k = do_keyop(vcpu, KVM_S390_KEYOP_RRBE, i, 0xff); + TEST_ASSERT((expected[i] & KEY_BITS_RC) == k, + "Old R or C value mismatch! expected: %#x, got %#x", + expected[i] & KEY_BITS_RC, k); + if (i == BUF_PAGES / 2) + fault_in_buffer(vcpu, fault_in, 3); + } + + for (i = 0; i < BUF_PAGES; i++) + expected[i] &= ~KEY_BIT_R; + + /* Verify that only the R bit has been cleared */ + fault_in_buffer(vcpu, fault_in, 4); + get_skeys(vcpu, tmp); + compare(tmp, expected, "New value mismatch", fault_in); +} + +static void test_iske(struct kvm_vcpu *vcpu, int fault_in) +{ + int i; + + /* Set storage keys to a sequential pattern */ + fault_in_buffer(vcpu, fault_in, 1); + set_pattern(expected); + set_skeys(vcpu, expected); + + /* Call the ISKE KEYOP ioctl on each page and verify the result */ + fault_in_buffer(vcpu, fault_in, 2); + for (i = 0; i < BUF_PAGES; i++) { + tmp[i] = do_keyop(vcpu, KVM_S390_KEYOP_ISKE, i, 0xff); + if (i == BUF_PAGES / 2) + fault_in_buffer(vcpu, fault_in, 3); + } + compare(tmp, expected, "Old value mismatch", fault_in); + + /* Check storage keys have not changed */ + fault_in_buffer(vcpu, fault_in, 4); + get_skeys(vcpu, tmp); + compare(tmp, expected, "Storage keys values changed", fault_in); +} + +static void test_sske(struct kvm_vcpu *vcpu, int fault_in) +{ + int i; + + /* Set storage keys to a sequential pattern */ + fault_in_buffer(vcpu, fault_in, 1); + set_pattern(tmp); + set_skeys(vcpu, tmp); + + /* Call the SSKE KEYOP ioctl on each page and verify the result */ + fault_in_buffer(vcpu, fault_in, 2); + for (i = 0; i < BUF_PAGES; i++) { + expected[i] = ~tmp[i] & KEY_BITS_ALL; + /* Set the new storage keys to be the bit-inversion of the previous ones */ + old[i] = do_keyop(vcpu, KVM_S390_KEYOP_SSKE, i, expected[i] | 1); + if (i == BUF_PAGES / 2) + fault_in_buffer(vcpu, fault_in, 3); + } + compare(old, tmp, "Old value mismatch", fault_in); + + /* Verify that the storage keys have been set correctly */ + fault_in_buffer(vcpu, fault_in, 4); + get_skeys(vcpu, tmp); + compare(tmp, expected, "New value mismatch", fault_in); +} + +static struct testdef { + const char *name; + void (*test)(struct kvm_vcpu *vcpu, int fault_in_location); + int n_fault_in_locations; +} testplan[] = { + { "Initialization", test_init, 5 }, + { "RRBE", test_rrbe, 5 }, + { "ISKE", test_iske, 5 }, + { "SSKE", test_sske, 5 }, +}; + +static void run_test(void (*the_test)(struct kvm_vcpu *, int), int fault_in_location) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + int r; + + vm = vm_create_barebones(); + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, GUEST_PAGES, 0); + vcpu = __vm_vcpu_add(vm, 0); + + r = _get_skeys(vcpu, tmp); + TEST_ASSERT(r == KVM_S390_GET_SKEYS_NONE, + "Storage keys are not disabled initially, r=%d", r); + + clear_all(); + + the_test(vcpu, fault_in_location); + + kvm_vm_free(vm); +} + +int main(int argc, char *argv[]) +{ + int i, f; + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_KEYOP)); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_UCONTROL)); + + ksft_print_header(); + for (i = 0, f = 0; i < ARRAY_SIZE(testplan); i++) + f += testplan[i].n_fault_in_locations; + ksft_set_plan(f); + + for (i = 0; i < ARRAY_SIZE(testplan); i++) { + for (f = 0; f < testplan[i].n_fault_in_locations; f++) { + run_test(testplan[i].test, f); + ksft_test_result_pass("%s (fault-in location %d)\n", testplan[i].name, f); + } + } + + ksft_finished(); /* Print results and exit() accordingly */ +} -- 2.52.0