diff options
Diffstat (limited to 'tools/testing/selftests/kvm')
| -rw-r--r-- | tools/testing/selftests/kvm/.gitignore | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/Makefile | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/aarch64/page_fault_test.c | 594 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/include/aarch64/processor.h | 8 |
4 files changed, 604 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 2f0d705db9db..4a30d684e208 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -4,6 +4,7 @@ /aarch64/debug-exceptions /aarch64/get-reg-list /aarch64/hypercalls +/aarch64/page_fault_test /aarch64/psci_test /aarch64/vcpu_width_config /aarch64/vgic_init diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 08a2606aff33..50c30335460f 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -153,6 +153,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/arch_timer TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list TEST_GEN_PROGS_aarch64 += aarch64/hypercalls +TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test TEST_GEN_PROGS_aarch64 += aarch64/psci_test TEST_GEN_PROGS_aarch64 += aarch64/vcpu_width_config TEST_GEN_PROGS_aarch64 += aarch64/vgic_init diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c new file mode 100644 index 000000000000..28859a96053f --- /dev/null +++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c @@ -0,0 +1,594 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * page_fault_test.c - Test stage 2 faults. + * + * This test tries different combinations of guest accesses (e.g., write, + * S1PTW), backing source type (e.g., anon) and types of faults (e.g., read on + * hugetlbfs with a hole). It checks that the expected handling method is + * called (e.g., uffd faults with the right address and write/read flag). + */ + +#define _GNU_SOURCE +#include <linux/bitmap.h> +#include <fcntl.h> +#include <test_util.h> +#include <kvm_util.h> +#include <processor.h> +#include <asm/sysreg.h> +#include <linux/bitfield.h> +#include "guest_modes.h" +#include "userfaultfd_util.h" + +/* Guest virtual addresses that point to the test page and its PTE. */ +#define TEST_GVA 0xc0000000 +#define TEST_EXEC_GVA (TEST_GVA + 0x8) +#define TEST_PTE_GVA 0xb0000000 +#define TEST_DATA 0x0123456789ABCDEF + +static uint64_t *guest_test_memory = (uint64_t *)TEST_GVA; + +#define CMD_NONE (0) +#define CMD_SKIP_TEST (1ULL << 1) +#define CMD_HOLE_PT (1ULL << 2) +#define CMD_HOLE_DATA (1ULL << 3) + +#define PREPARE_FN_NR 10 +#define CHECK_FN_NR 10 + +struct test_desc { + const char *name; + uint64_t mem_mark_cmd; + /* Skip the test if any prepare function returns false */ + bool (*guest_prepare[PREPARE_FN_NR])(void); + void (*guest_test)(void); + void (*guest_test_check[CHECK_FN_NR])(void); + void (*dabt_handler)(struct ex_regs *regs); + void (*iabt_handler)(struct ex_regs *regs); + uint32_t pt_memslot_flags; + uint32_t data_memslot_flags; + bool skip; +}; + +struct test_params { + enum vm_mem_backing_src_type src_type; + struct test_desc *test_desc; +}; + +static inline void flush_tlb_page(uint64_t vaddr) +{ + uint64_t page = vaddr >> 12; + + dsb(ishst); + asm volatile("tlbi vaae1is, %0" :: "r" (page)); + dsb(ish); + isb(); +} + +static void guest_write64(void) +{ + uint64_t val; + + WRITE_ONCE(*guest_test_memory, TEST_DATA); + val = READ_ONCE(*guest_test_memory); + GUEST_ASSERT_EQ(val, TEST_DATA); +} + +/* Check the system for atomic instructions. */ +static bool guest_check_lse(void) +{ + uint64_t isar0 = read_sysreg(id_aa64isar0_el1); + uint64_t atomic; + + atomic = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR0_ATOMICS), isar0); + return atomic >= 2; +} + +static bool guest_check_dc_zva(void) +{ + uint64_t dczid = read_sysreg(dczid_el0); + uint64_t dzp = FIELD_GET(ARM64_FEATURE_MASK(DCZID_DZP), dczid); + + return dzp == 0; +} + +/* Compare and swap instruction. */ +static void guest_cas(void) +{ + uint64_t val; + + GUEST_ASSERT(guest_check_lse()); + asm volatile(".arch_extension lse\n" + "casal %0, %1, [%2]\n" + :: "r" (0), "r" (TEST_DATA), "r" (guest_test_memory)); + val = READ_ONCE(*guest_test_memory); + GUEST_ASSERT_EQ(val, TEST_DATA); +} + +static void guest_read64(void) +{ + uint64_t val; + + val = READ_ONCE(*guest_test_memory); + GUEST_ASSERT_EQ(val, 0); +} + +/* Address translation instruction */ +static void guest_at(void) +{ + uint64_t par; + + asm volatile("at s1e1r, %0" :: "r" (guest_test_memory)); + par = read_sysreg(par_el1); + isb(); + + /* Bit 1 indicates whether the AT was successful */ + GUEST_ASSERT_EQ(par & 1, 0); +} + +/* + * The size of the block written by "dc zva" is guaranteed to be between (2 << + * 0) and (2 << 9), which is safe in our case as we need the write to happen + * for at least a word, and not more than a page. + */ +static void guest_dc_zva(void) +{ + uint16_t val; + + asm volatile("dc zva, %0" :: "r" (guest_test_memory)); + dsb(ish); + val = READ_ONCE(*guest_test_memory); + GUEST_ASSERT_EQ(val, 0); +} + +/* + * Pre-indexing loads and stores don't have a valid syndrome (ESR_EL2.ISV==0). + * And that's special because KVM must take special care with those: they + * should still count as accesses for dirty logging or user-faulting, but + * should be handled differently on mmio. + */ +static void guest_ld_preidx(void) +{ + uint64_t val; + uint64_t addr = TEST_GVA - 8; + + /* + * This ends up accessing "TEST_GVA + 8 - 8", where "TEST_GVA - 8" is + * in a gap between memslots not backing by anything. + */ + asm volatile("ldr %0, [%1, #8]!" + : "=r" (val), "+r" (addr)); + GUEST_ASSERT_EQ(val, 0); + GUEST_ASSERT_EQ(addr, TEST_GVA); +} + +static void guest_st_preidx(void) +{ + uint64_t val = TEST_DATA; + uint64_t addr = TEST_GVA - 8; + + asm volatile("str %0, [%1, #8]!" + : "+r" (val), "+r" (addr)); + + GUEST_ASSERT_EQ(addr, TEST_GVA); + val = READ_ONCE(*guest_test_memory); +} + +static bool guest_set_ha(void) +{ + uint64_t mmfr1 = read_sysreg(id_aa64mmfr1_el1); + uint64_t hadbs, tcr; + + /* Skip if HA is not supported. */ + hadbs = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR1_HADBS), mmfr1); + if (hadbs == 0) + return false; + + tcr = read_sysreg(tcr_el1) | TCR_EL1_HA; + write_sysreg(tcr, tcr_el1); + isb(); + + return true; +} + +static bool guest_clear_pte_af(void) +{ + *((uint64_t *)TEST_PTE_GVA) &= ~PTE_AF; + flush_tlb_page(TEST_GVA); + + return true; +} + +static void guest_check_pte_af(void) +{ + dsb(ish); + GUEST_ASSERT_EQ(*((uint64_t *)TEST_PTE_GVA) & PTE_AF, PTE_AF); +} + +static void guest_exec(void) +{ + int (*code)(void) = (int (*)(void))TEST_EXEC_GVA; + int ret; + + ret = code(); + GUEST_ASSERT_EQ(ret, 0x77); +} + +static bool guest_prepare(struct test_desc *test) +{ + bool (*prepare_fn)(void); + int i; + + for (i = 0; i < PREPARE_FN_NR; i++) { + prepare_fn = test->guest_prepare[i]; + if (prepare_fn && !prepare_fn()) + return false; + } + + return true; +} + +static void guest_test_check(struct test_desc *test) +{ + void (*check_fn)(void); + int i; + + for (i = 0; i < CHECK_FN_NR; i++) { + check_fn = test->guest_test_check[i]; + if (check_fn) + check_fn(); + } +} + +static void guest_code(struct test_desc *test) +{ + if (!guest_prepare(test)) + GUEST_SYNC(CMD_SKIP_TEST); + + GUEST_SYNC(test->mem_mark_cmd); + + if (test->guest_test) + test->guest_test(); + + guest_test_check(test); + GUEST_DONE(); +} + +static void no_dabt_handler(struct ex_regs *regs) +{ + GUEST_ASSERT_1(false, read_sysreg(far_el1)); +} + +static void no_iabt_handler(struct ex_regs *regs) +{ + GUEST_ASSERT_1(false, regs->pc); +} + +/* Returns true to continue the test, and false if it should be skipped. */ +static bool punch_hole_in_backing_store(struct kvm_vm *vm, + struct userspace_mem_region *region) +{ + void *hva = (void *)region->region.userspace_addr; + uint64_t paging_size = region->region.memory_size; + int ret, fd = region->fd; + + if (fd != -1) { + ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, + 0, paging_size); + TEST_ASSERT(ret == 0, "fallocate failed\n"); + } else { + ret = madvise(hva, paging_size, MADV_DONTNEED); + TEST_ASSERT(ret == 0, "madvise failed\n"); + } + + return true; +} + +/* Returns true to continue the test, and false if it should be skipped. */ +static bool handle_cmd(struct kvm_vm *vm, int cmd) +{ + struct userspace_mem_region *data_region, *pt_region; + bool continue_test = true; + + data_region = vm_get_mem_region(vm, MEM_REGION_TEST_DATA); + pt_region = vm_get_mem_region(vm, MEM_REGION_PT); + + if (cmd == CMD_SKIP_TEST) + continue_test = false; + + if (cmd & CMD_HOLE_PT) + continue_test = punch_hole_in_backing_store(vm, pt_region); + if (cmd & CMD_HOLE_DATA) + continue_test = punch_hole_in_backing_store(vm, data_region); + + return continue_test; +} + +typedef uint32_t aarch64_insn_t; +extern aarch64_insn_t __exec_test[2]; + +noinline void __return_0x77(void) +{ + asm volatile("__exec_test: mov x0, #0x77\n" + "ret\n"); +} + +/* + * Note that this function runs on the host before the test VM starts: there's + * no need to sync the D$ and I$ caches. + */ +static void load_exec_code_for_test(struct kvm_vm *vm) +{ + uint64_t *code; + struct userspace_mem_region *region; + void *hva; + + region = vm_get_mem_region(vm, MEM_REGION_TEST_DATA); + hva = (void *)region->region.userspace_addr; + + assert(TEST_EXEC_GVA > TEST_GVA); + code = hva + TEST_EXEC_GVA - TEST_GVA; + memcpy(code, __exec_test, sizeof(__exec_test)); +} + +static void setup_abort_handlers(struct kvm_vm *vm, struct kvm_vcpu *vcpu, + struct test_desc *test) +{ + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_DABT, no_dabt_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_IABT, no_iabt_handler); +} + +static void setup_gva_maps(struct kvm_vm *vm) +{ + struct userspace_mem_region *region; + uint64_t pte_gpa; + + region = vm_get_mem_region(vm, MEM_REGION_TEST_DATA); + /* Map TEST_GVA first. This will install a new PTE. */ + virt_pg_map(vm, TEST_GVA, region->region.guest_phys_addr); + /* Then map TEST_PTE_GVA to the above PTE. */ + pte_gpa = addr_hva2gpa(vm, virt_get_pte_hva(vm, TEST_GVA)); + virt_pg_map(vm, TEST_PTE_GVA, pte_gpa); +} + +enum pf_test_memslots { + CODE_AND_DATA_MEMSLOT, + PAGE_TABLE_MEMSLOT, + TEST_DATA_MEMSLOT, +}; + +/* + * Create a memslot for code and data at pfn=0, and test-data and PT ones + * at max_gfn. + */ +static void setup_memslots(struct kvm_vm *vm, struct test_params *p) +{ + uint64_t backing_src_pagesz = get_backing_src_pagesz(p->src_type); + uint64_t guest_page_size = vm->page_size; + uint64_t max_gfn = vm_compute_max_gfn(vm); + /* Enough for 2M of code when using 4K guest pages. */ + uint64_t code_npages = 512; + uint64_t pt_size, data_size, data_gpa; + + /* + * This test requires 1 pgd, 2 pud, 4 pmd, and 6 pte pages when using + * VM_MODE_P48V48_4K. Note that the .text takes ~1.6MBs. That's 13 + * pages. VM_MODE_P48V48_4K is the mode with most PT pages; let's use + * twice that just in case. + */ + pt_size = 26 * guest_page_size; + + /* memslot sizes and gpa's must be aligned to the backing page size */ + pt_size = align_up(pt_size, backing_src_pagesz); + data_size = align_up(guest_page_size, backing_src_pagesz); + data_gpa = (max_gfn * guest_page_size) - data_size; + data_gpa = align_down(data_gpa, backing_src_pagesz); + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, + CODE_AND_DATA_MEMSLOT, code_npages, 0); + vm->memslots[MEM_REGION_CODE] = CODE_AND_DATA_MEMSLOT; + vm->memslots[MEM_REGION_DATA] = CODE_AND_DATA_MEMSLOT; + + vm_userspace_mem_region_add(vm, p->src_type, data_gpa - pt_size, + PAGE_TABLE_MEMSLOT, pt_size / guest_page_size, + p->test_desc->pt_memslot_flags); + vm->memslots[MEM_REGION_PT] = PAGE_TABLE_MEMSLOT; + + vm_userspace_mem_region_add(vm, p->src_type, data_gpa, TEST_DATA_MEMSLOT, + data_size / guest_page_size, + p->test_desc->data_memslot_flags); + vm->memslots[MEM_REGION_TEST_DATA] = TEST_DATA_MEMSLOT; +} + +static void print_test_banner(enum vm_guest_mode mode, struct test_params *p) +{ + struct test_desc *test = p->test_desc; + + pr_debug("Test: %s\n", test->name); + pr_debug("Testing guest mode: %s\n", vm_guest_mode_string(mode)); + pr_debug("Testing memory backing src type: %s\n", + vm_mem_backing_src_alias(p->src_type)->name); +} + +/* + * This function either succeeds, skips the test (after setting test->skip), or + * fails with a TEST_FAIL that aborts all tests. + */ +static void vcpu_run_loop(struct kvm_vm *vm, struct kvm_vcpu *vcpu, + struct test_desc *test) +{ + struct ucall uc; + + for (;;) { + vcpu_run(vcpu); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_SYNC: + if (!handle_cmd(vm, uc.args[1])) { + test->skip = true; + goto done; + } + break; + case UCALL_ABORT: + REPORT_GUEST_ASSERT_2(uc, "values: %#lx, %#lx"); + break; + case UCALL_DONE: + goto done; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + } + +done: + pr_debug(test->skip ? "Skipped.\n" : "Done.\n"); +} + +static void run_test(enum vm_guest_mode mode, void *arg) +{ + struct test_params *p = (struct test_params *)arg; + struct test_desc *test = p->test_desc; + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + + print_test_banner(mode, p); + + vm = ____vm_create(mode); + setup_memslots(vm, p); + kvm_vm_elf_load(vm, program_invocation_name); + vcpu = vm_vcpu_add(vm, 0, guest_code); + + setup_gva_maps(vm); + + ucall_init(vm, NULL); + + load_exec_code_for_test(vm); + setup_abort_handlers(vm, vcpu, test); + vcpu_args_set(vcpu, 1, test); + + vcpu_run_loop(vm, vcpu, test); + + ucall_uninit(vm); + kvm_vm_free(vm); +} + +static void help(char *name) +{ + puts(""); + printf("usage: %s [-h] [-s mem-type]\n", name); + puts(""); + guest_modes_help(); + backing_src_help("-s"); + puts(""); +} + +#define SNAME(s) #s +#define SCAT2(a, b) SNAME(a ## _ ## b) +#define SCAT3(a, b, c) SCAT2(a, SCAT2(b, c)) + +#define _CHECK(_test) _CHECK_##_test +#define _PREPARE(_test) _PREPARE_##_test +#define _PREPARE_guest_read64 NULL +#define _PREPARE_guest_ld_preidx NULL +#define _PREPARE_guest_write64 NULL +#define _PREPARE_guest_st_preidx NULL +#define _PREPARE_guest_exec NULL +#define _PREPARE_guest_at NULL +#define _PREPARE_guest_dc_zva guest_check_dc_zva +#define _PREPARE_guest_cas guest_check_lse + +/* With or without access flag checks */ +#define _PREPARE_with_af guest_set_ha, guest_clear_pte_af +#define _PREPARE_no_af NULL +#define _CHECK_with_af guest_check_pte_af +#define _CHECK_no_af NULL + +/* Performs an access and checks that no faults were triggered. */ +#define TEST_ACCESS(_access, _with_af, _mark_cmd) \ +{ \ + .name = SCAT3(_access, _with_af, #_mark_cmd), \ + .guest_prepare = { _PREPARE(_with_af), \ + _PREPARE(_access) }, \ + .mem_mark_cmd = _mark_cmd, \ + .guest_test = _access, \ + .guest_test_check = { _CHECK(_with_af) }, \ +} + +static struct test_desc tests[] = { + + /* Check that HW is setting the Access Flag (AF) (sanity checks). */ + TEST_ACCESS(guest_read64, with_af, CMD_NONE), + TEST_ACCESS(guest_ld_preidx, with_af, CMD_NONE), + TEST_ACCESS(guest_cas, with_af, CMD_NONE), + TEST_ACCESS(guest_write64, with_af, CMD_NONE), + TEST_ACCESS(guest_st_preidx, with_af, CMD_NONE), + TEST_ACCESS(guest_dc_zva, with_af, CMD_NONE), + TEST_ACCESS(guest_exec, with_af, CMD_NONE), + + /* + * Punch a hole in the data backing store, and then try multiple + * accesses: reads should rturn zeroes, and writes should + * re-populate the page. Moreover, the test also check that no + * exception was generated in the guest. Note that this + * reading/writing behavior is the same as reading/writing a + * punched page (with fallocate(FALLOC_FL_PUNCH_HOLE)) from + * userspace. + */ + TEST_ACCESS(guest_read64, no_af, CMD_HOLE_DATA), + TEST_ACCESS(guest_cas, no_af, CMD_HOLE_DATA), + TEST_ACCESS(guest_ld_preidx, no_af, CMD_HOLE_DATA), + TEST_ACCESS(guest_write64, no_af, CMD_HOLE_DATA), + TEST_ACCESS(guest_st_preidx, no_af, CMD_HOLE_DATA), + TEST_ACCESS(guest_at, no_af, CMD_HOLE_DATA), + TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_DATA), + + { 0 } +}; + +static void for_each_test_and_guest_mode(enum vm_mem_backing_src_type src_type) +{ + struct test_desc *t; + + for (t = &tests[0]; t->name; t++) { + if (t->skip) + continue; + + struct test_params p = { + .src_type = src_type, + .test_desc = t, + }; + + for_each_guest_mode(run_test, &p); + } +} + +int main(int argc, char *argv[]) +{ + enum vm_mem_backing_src_type src_type; + int opt; + + setbuf(stdout, NULL); + + src_type = DEFAULT_VM_MEM_SRC; + + while ((opt = getopt(argc, argv, "hm:s:")) != -1) { + switch (opt) { + case 'm': + guest_modes_cmdline(optarg); + break; + case 's': + src_type = parse_backing_src_type(optarg); + break; + case 'h': + default: + help(argv[0]); + exit(0); + } + } + + for_each_test_and_guest_mode(src_type); + return 0; +} diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h index c1ddca8db225..5f977528e09c 100644 --- a/tools/testing/selftests/kvm/include/aarch64/processor.h +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h @@ -105,11 +105,19 @@ enum { #define ESR_EC_MASK (ESR_EC_NUM - 1) #define ESR_EC_SVC64 0x15 +#define ESR_EC_IABT 0x21 +#define ESR_EC_DABT 0x25 #define ESR_EC_HW_BP_CURRENT 0x31 #define ESR_EC_SSTEP_CURRENT 0x33 #define ESR_EC_WP_CURRENT 0x35 #define ESR_EC_BRK_INS 0x3c +/* Access flag */ +#define PTE_AF (1ULL << 10) + +/* Access flag update enable/disable */ +#define TCR_EL1_HA (1ULL << 39) + void aarch64_get_supported_page_sizes(uint32_t ipa, bool *ps4k, bool *ps16k, bool *ps64k); |