diff options
Diffstat (limited to 'tools/testing/selftests/kvm/s390x/tprot.c')
-rw-r--r-- | tools/testing/selftests/kvm/s390x/tprot.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/s390x/tprot.c b/tools/testing/selftests/kvm/s390x/tprot.c new file mode 100644 index 0000000000..c73f948c9b --- /dev/null +++ b/tools/testing/selftests/kvm/s390x/tprot.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Test TEST PROTECTION emulation. + * + * Copyright IBM Corp. 2021 + */ +#include <sys/mman.h> +#include "test_util.h" +#include "kvm_util.h" +#include "kselftest.h" + +#define PAGE_SHIFT 12 +#define PAGE_SIZE (1 << PAGE_SHIFT) +#define CR0_FETCH_PROTECTION_OVERRIDE (1UL << (63 - 38)) +#define CR0_STORAGE_PROTECTION_OVERRIDE (1UL << (63 - 39)) + +static __aligned(PAGE_SIZE) uint8_t pages[2][PAGE_SIZE]; +static uint8_t *const page_store_prot = pages[0]; +static uint8_t *const page_fetch_prot = pages[1]; + +/* Nonzero return value indicates that address not mapped */ +static int set_storage_key(void *addr, uint8_t key) +{ + int not_mapped = 0; + + asm volatile ( + "lra %[addr], 0(0,%[addr])\n" + " jz 0f\n" + " llill %[not_mapped],1\n" + " j 1f\n" + "0: sske %[key], %[addr]\n" + "1:" + : [addr] "+&a" (addr), [not_mapped] "+r" (not_mapped) + : [key] "r" (key) + : "cc" + ); + return -not_mapped; +} + +enum permission { + READ_WRITE = 0, + READ = 1, + RW_PROTECTED = 2, + TRANSL_UNAVAIL = 3, +}; + +static enum permission test_protection(void *addr, uint8_t key) +{ + uint64_t mask; + + asm volatile ( + "tprot %[addr], 0(%[key])\n" + " ipm %[mask]\n" + : [mask] "=r" (mask) + : [addr] "Q" (*(char *)addr), + [key] "a" (key) + : "cc" + ); + + return (enum permission)(mask >> 28); +} + +enum stage { + STAGE_INIT_SIMPLE, + TEST_SIMPLE, + STAGE_INIT_FETCH_PROT_OVERRIDE, + TEST_FETCH_PROT_OVERRIDE, + TEST_STORAGE_PROT_OVERRIDE, + STAGE_END /* must be the last entry (it's the amount of tests) */ +}; + +struct test { + enum stage stage; + void *addr; + uint8_t key; + enum permission expected; +} tests[] = { + /* + * We perform each test in the array by executing TEST PROTECTION on + * the specified addr with the specified key and checking if the returned + * permissions match the expected value. + * Both guest and host cooperate to set up the required test conditions. + * A central condition is that the page targeted by addr has to be DAT + * protected in the host mappings, in order for KVM to emulate the + * TEST PROTECTION instruction. + * Since the page tables are shared, the host uses mprotect to achieve + * this. + * + * Test resulting in RW_PROTECTED/TRANSL_UNAVAIL will be interpreted + * by SIE, not KVM, but there is no harm in testing them also. + * See Enhanced Suppression-on-Protection Facilities in the + * Interpretive-Execution Mode + */ + /* + * guest: set storage key of page_store_prot to 1 + * storage key of page_fetch_prot to 9 and enable + * protection for it + * STAGE_INIT_SIMPLE + * host: write protect both via mprotect + */ + /* access key 0 matches any storage key -> RW */ + { TEST_SIMPLE, page_store_prot, 0x00, READ_WRITE }, + /* access key matches storage key -> RW */ + { TEST_SIMPLE, page_store_prot, 0x10, READ_WRITE }, + /* mismatched keys, but no fetch protection -> RO */ + { TEST_SIMPLE, page_store_prot, 0x20, READ }, + /* access key 0 matches any storage key -> RW */ + { TEST_SIMPLE, page_fetch_prot, 0x00, READ_WRITE }, + /* access key matches storage key -> RW */ + { TEST_SIMPLE, page_fetch_prot, 0x90, READ_WRITE }, + /* mismatched keys, fetch protection -> inaccessible */ + { TEST_SIMPLE, page_fetch_prot, 0x10, RW_PROTECTED }, + /* page 0 not mapped yet -> translation not available */ + { TEST_SIMPLE, (void *)0x00, 0x10, TRANSL_UNAVAIL }, + /* + * host: try to map page 0 + * guest: set storage key of page 0 to 9 and enable fetch protection + * STAGE_INIT_FETCH_PROT_OVERRIDE + * host: write protect page 0 + * enable fetch protection override + */ + /* mismatched keys, fetch protection, but override applies -> RO */ + { TEST_FETCH_PROT_OVERRIDE, (void *)0x00, 0x10, READ }, + /* mismatched keys, fetch protection, override applies to 0-2048 only -> inaccessible */ + { TEST_FETCH_PROT_OVERRIDE, (void *)2049, 0x10, RW_PROTECTED }, + /* + * host: enable storage protection override + */ + /* mismatched keys, but override applies (storage key 9) -> RW */ + { TEST_STORAGE_PROT_OVERRIDE, page_fetch_prot, 0x10, READ_WRITE }, + /* mismatched keys, no fetch protection, override doesn't apply -> RO */ + { TEST_STORAGE_PROT_OVERRIDE, page_store_prot, 0x20, READ }, + /* mismatched keys, but override applies (storage key 9) -> RW */ + { TEST_STORAGE_PROT_OVERRIDE, (void *)2049, 0x10, READ_WRITE }, + /* end marker */ + { STAGE_END, 0, 0, 0 }, +}; + +static enum stage perform_next_stage(int *i, bool mapped_0) +{ + enum stage stage = tests[*i].stage; + enum permission result; + bool skip; + + for (; tests[*i].stage == stage; (*i)++) { + /* + * Some fetch protection override tests require that page 0 + * be mapped, however, when the hosts tries to map that page via + * vm_vaddr_alloc, it may happen that some other page gets mapped + * instead. + * In order to skip these tests we detect this inside the guest + */ + skip = tests[*i].addr < (void *)4096 && + tests[*i].expected != TRANSL_UNAVAIL && + !mapped_0; + if (!skip) { + result = test_protection(tests[*i].addr, tests[*i].key); + __GUEST_ASSERT(result == tests[*i].expected, + "Wanted %u, got %u, for i = %u", + tests[*i].expected, result, *i); + } + } + return stage; +} + +static void guest_code(void) +{ + bool mapped_0; + int i = 0; + + GUEST_ASSERT_EQ(set_storage_key(page_store_prot, 0x10), 0); + GUEST_ASSERT_EQ(set_storage_key(page_fetch_prot, 0x98), 0); + GUEST_SYNC(STAGE_INIT_SIMPLE); + GUEST_SYNC(perform_next_stage(&i, false)); + + /* Fetch-protection override */ + mapped_0 = !set_storage_key((void *)0, 0x98); + GUEST_SYNC(STAGE_INIT_FETCH_PROT_OVERRIDE); + GUEST_SYNC(perform_next_stage(&i, mapped_0)); + + /* Storage-protection override */ + GUEST_SYNC(perform_next_stage(&i, mapped_0)); +} + +#define HOST_SYNC_NO_TAP(vcpup, stage) \ +({ \ + struct kvm_vcpu *__vcpu = (vcpup); \ + struct ucall uc; \ + int __stage = (stage); \ + \ + vcpu_run(__vcpu); \ + get_ucall(__vcpu, &uc); \ + if (uc.cmd == UCALL_ABORT) \ + REPORT_GUEST_ASSERT(uc); \ + TEST_ASSERT_EQ(uc.cmd, UCALL_SYNC); \ + TEST_ASSERT_EQ(uc.args[1], __stage); \ +}) + +#define HOST_SYNC(vcpu, stage) \ +({ \ + HOST_SYNC_NO_TAP(vcpu, stage); \ + ksft_test_result_pass("" #stage "\n"); \ +}) + +int main(int argc, char *argv[]) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct kvm_run *run; + vm_vaddr_t guest_0_page; + + ksft_print_header(); + ksft_set_plan(STAGE_END); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + run = vcpu->run; + + HOST_SYNC(vcpu, STAGE_INIT_SIMPLE); + mprotect(addr_gva2hva(vm, (vm_vaddr_t)pages), PAGE_SIZE * 2, PROT_READ); + HOST_SYNC(vcpu, TEST_SIMPLE); + + guest_0_page = vm_vaddr_alloc(vm, PAGE_SIZE, 0); + if (guest_0_page != 0) { + /* Use NO_TAP so we don't get a PASS print */ + HOST_SYNC_NO_TAP(vcpu, STAGE_INIT_FETCH_PROT_OVERRIDE); + ksft_test_result_skip("STAGE_INIT_FETCH_PROT_OVERRIDE - " + "Did not allocate page at 0\n"); + } else { + HOST_SYNC(vcpu, STAGE_INIT_FETCH_PROT_OVERRIDE); + } + if (guest_0_page == 0) + mprotect(addr_gva2hva(vm, (vm_vaddr_t)0), PAGE_SIZE, PROT_READ); + run->s.regs.crs[0] |= CR0_FETCH_PROTECTION_OVERRIDE; + run->kvm_dirty_regs = KVM_SYNC_CRS; + HOST_SYNC(vcpu, TEST_FETCH_PROT_OVERRIDE); + + run->s.regs.crs[0] |= CR0_STORAGE_PROTECTION_OVERRIDE; + run->kvm_dirty_regs = KVM_SYNC_CRS; + HOST_SYNC(vcpu, TEST_STORAGE_PROT_OVERRIDE); + + kvm_vm_free(vm); + + ksft_finished(); /* Print results and exit() accordingly */ +} |