diff options
Diffstat (limited to 'tools/testing/selftests/kvm/aarch64/debug-exceptions.c')
-rw-r--r-- | tools/testing/selftests/kvm/aarch64/debug-exceptions.c | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c new file mode 100644 index 0000000000..f5b6cb3a00 --- /dev/null +++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c @@ -0,0 +1,607 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_util.h> +#include <kvm_util.h> +#include <processor.h> +#include <linux/bitfield.h> + +#define MDSCR_KDE (1 << 13) +#define MDSCR_MDE (1 << 15) +#define MDSCR_SS (1 << 0) + +#define DBGBCR_LEN8 (0xff << 5) +#define DBGBCR_EXEC (0x0 << 3) +#define DBGBCR_EL1 (0x1 << 1) +#define DBGBCR_E (0x1 << 0) +#define DBGBCR_LBN_SHIFT 16 +#define DBGBCR_BT_SHIFT 20 +#define DBGBCR_BT_ADDR_LINK_CTX (0x1 << DBGBCR_BT_SHIFT) +#define DBGBCR_BT_CTX_LINK (0x3 << DBGBCR_BT_SHIFT) + +#define DBGWCR_LEN8 (0xff << 5) +#define DBGWCR_RD (0x1 << 3) +#define DBGWCR_WR (0x2 << 3) +#define DBGWCR_EL1 (0x1 << 1) +#define DBGWCR_E (0x1 << 0) +#define DBGWCR_LBN_SHIFT 16 +#define DBGWCR_WT_SHIFT 20 +#define DBGWCR_WT_LINK (0x1 << DBGWCR_WT_SHIFT) + +#define SPSR_D (1 << 9) +#define SPSR_SS (1 << 21) + +extern unsigned char sw_bp, sw_bp2, hw_bp, hw_bp2, bp_svc, bp_brk, hw_wp, ss_start, hw_bp_ctx; +extern unsigned char iter_ss_begin, iter_ss_end; +static volatile uint64_t sw_bp_addr, hw_bp_addr; +static volatile uint64_t wp_addr, wp_data_addr; +static volatile uint64_t svc_addr; +static volatile uint64_t ss_addr[4], ss_idx; +#define PC(v) ((uint64_t)&(v)) + +#define GEN_DEBUG_WRITE_REG(reg_name) \ +static void write_##reg_name(int num, uint64_t val) \ +{ \ + switch (num) { \ + case 0: \ + write_sysreg(val, reg_name##0_el1); \ + break; \ + case 1: \ + write_sysreg(val, reg_name##1_el1); \ + break; \ + case 2: \ + write_sysreg(val, reg_name##2_el1); \ + break; \ + case 3: \ + write_sysreg(val, reg_name##3_el1); \ + break; \ + case 4: \ + write_sysreg(val, reg_name##4_el1); \ + break; \ + case 5: \ + write_sysreg(val, reg_name##5_el1); \ + break; \ + case 6: \ + write_sysreg(val, reg_name##6_el1); \ + break; \ + case 7: \ + write_sysreg(val, reg_name##7_el1); \ + break; \ + case 8: \ + write_sysreg(val, reg_name##8_el1); \ + break; \ + case 9: \ + write_sysreg(val, reg_name##9_el1); \ + break; \ + case 10: \ + write_sysreg(val, reg_name##10_el1); \ + break; \ + case 11: \ + write_sysreg(val, reg_name##11_el1); \ + break; \ + case 12: \ + write_sysreg(val, reg_name##12_el1); \ + break; \ + case 13: \ + write_sysreg(val, reg_name##13_el1); \ + break; \ + case 14: \ + write_sysreg(val, reg_name##14_el1); \ + break; \ + case 15: \ + write_sysreg(val, reg_name##15_el1); \ + break; \ + default: \ + GUEST_ASSERT(0); \ + } \ +} + +/* Define write_dbgbcr()/write_dbgbvr()/write_dbgwcr()/write_dbgwvr() */ +GEN_DEBUG_WRITE_REG(dbgbcr) +GEN_DEBUG_WRITE_REG(dbgbvr) +GEN_DEBUG_WRITE_REG(dbgwcr) +GEN_DEBUG_WRITE_REG(dbgwvr) + +static void reset_debug_state(void) +{ + uint8_t brps, wrps, i; + uint64_t dfr0; + + asm volatile("msr daifset, #8"); + + write_sysreg(0, osdlr_el1); + write_sysreg(0, oslar_el1); + isb(); + + write_sysreg(0, mdscr_el1); + write_sysreg(0, contextidr_el1); + + /* Reset all bcr/bvr/wcr/wvr registers */ + dfr0 = read_sysreg(id_aa64dfr0_el1); + brps = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_BRPS), dfr0); + for (i = 0; i <= brps; i++) { + write_dbgbcr(i, 0); + write_dbgbvr(i, 0); + } + wrps = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_WRPS), dfr0); + for (i = 0; i <= wrps; i++) { + write_dbgwcr(i, 0); + write_dbgwvr(i, 0); + } + + isb(); +} + +static void enable_os_lock(void) +{ + write_sysreg(1, oslar_el1); + isb(); + + GUEST_ASSERT(read_sysreg(oslsr_el1) & 2); +} + +static void enable_monitor_debug_exceptions(void) +{ + uint32_t mdscr; + + asm volatile("msr daifclr, #8"); + + mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_MDE; + write_sysreg(mdscr, mdscr_el1); + isb(); +} + +static void install_wp(uint8_t wpn, uint64_t addr) +{ + uint32_t wcr; + + wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E; + write_dbgwcr(wpn, wcr); + write_dbgwvr(wpn, addr); + + isb(); + + enable_monitor_debug_exceptions(); +} + +static void install_hw_bp(uint8_t bpn, uint64_t addr) +{ + uint32_t bcr; + + bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E; + write_dbgbcr(bpn, bcr); + write_dbgbvr(bpn, addr); + isb(); + + enable_monitor_debug_exceptions(); +} + +static void install_wp_ctx(uint8_t addr_wp, uint8_t ctx_bp, uint64_t addr, + uint64_t ctx) +{ + uint32_t wcr; + uint64_t ctx_bcr; + + /* Setup a context-aware breakpoint for Linked Context ID Match */ + ctx_bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E | + DBGBCR_BT_CTX_LINK; + write_dbgbcr(ctx_bp, ctx_bcr); + write_dbgbvr(ctx_bp, ctx); + + /* Setup a linked watchpoint (linked to the context-aware breakpoint) */ + wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E | + DBGWCR_WT_LINK | ((uint32_t)ctx_bp << DBGWCR_LBN_SHIFT); + write_dbgwcr(addr_wp, wcr); + write_dbgwvr(addr_wp, addr); + isb(); + + enable_monitor_debug_exceptions(); +} + +void install_hw_bp_ctx(uint8_t addr_bp, uint8_t ctx_bp, uint64_t addr, + uint64_t ctx) +{ + uint32_t addr_bcr, ctx_bcr; + + /* Setup a context-aware breakpoint for Linked Context ID Match */ + ctx_bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E | + DBGBCR_BT_CTX_LINK; + write_dbgbcr(ctx_bp, ctx_bcr); + write_dbgbvr(ctx_bp, ctx); + + /* + * Setup a normal breakpoint for Linked Address Match, and link it + * to the context-aware breakpoint. + */ + addr_bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E | + DBGBCR_BT_ADDR_LINK_CTX | + ((uint32_t)ctx_bp << DBGBCR_LBN_SHIFT); + write_dbgbcr(addr_bp, addr_bcr); + write_dbgbvr(addr_bp, addr); + isb(); + + enable_monitor_debug_exceptions(); +} + +static void install_ss(void) +{ + uint32_t mdscr; + + asm volatile("msr daifclr, #8"); + + mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_SS; + write_sysreg(mdscr, mdscr_el1); + isb(); +} + +static volatile char write_data; + +static void guest_code(uint8_t bpn, uint8_t wpn, uint8_t ctx_bpn) +{ + uint64_t ctx = 0xabcdef; /* a random context number */ + + /* Software-breakpoint */ + reset_debug_state(); + asm volatile("sw_bp: brk #0"); + GUEST_ASSERT_EQ(sw_bp_addr, PC(sw_bp)); + + /* Hardware-breakpoint */ + reset_debug_state(); + install_hw_bp(bpn, PC(hw_bp)); + asm volatile("hw_bp: nop"); + GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp)); + + /* Hardware-breakpoint + svc */ + reset_debug_state(); + install_hw_bp(bpn, PC(bp_svc)); + asm volatile("bp_svc: svc #0"); + GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_svc)); + GUEST_ASSERT_EQ(svc_addr, PC(bp_svc) + 4); + + /* Hardware-breakpoint + software-breakpoint */ + reset_debug_state(); + install_hw_bp(bpn, PC(bp_brk)); + asm volatile("bp_brk: brk #0"); + GUEST_ASSERT_EQ(sw_bp_addr, PC(bp_brk)); + GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_brk)); + + /* Watchpoint */ + reset_debug_state(); + install_wp(wpn, PC(write_data)); + write_data = 'x'; + GUEST_ASSERT_EQ(write_data, 'x'); + GUEST_ASSERT_EQ(wp_data_addr, PC(write_data)); + + /* Single-step */ + reset_debug_state(); + install_ss(); + ss_idx = 0; + asm volatile("ss_start:\n" + "mrs x0, esr_el1\n" + "add x0, x0, #1\n" + "msr daifset, #8\n" + : : : "x0"); + GUEST_ASSERT_EQ(ss_addr[0], PC(ss_start)); + GUEST_ASSERT_EQ(ss_addr[1], PC(ss_start) + 4); + GUEST_ASSERT_EQ(ss_addr[2], PC(ss_start) + 8); + + /* OS Lock does not block software-breakpoint */ + reset_debug_state(); + enable_os_lock(); + sw_bp_addr = 0; + asm volatile("sw_bp2: brk #0"); + GUEST_ASSERT_EQ(sw_bp_addr, PC(sw_bp2)); + + /* OS Lock blocking hardware-breakpoint */ + reset_debug_state(); + enable_os_lock(); + install_hw_bp(bpn, PC(hw_bp2)); + hw_bp_addr = 0; + asm volatile("hw_bp2: nop"); + GUEST_ASSERT_EQ(hw_bp_addr, 0); + + /* OS Lock blocking watchpoint */ + reset_debug_state(); + enable_os_lock(); + write_data = '\0'; + wp_data_addr = 0; + install_wp(wpn, PC(write_data)); + write_data = 'x'; + GUEST_ASSERT_EQ(write_data, 'x'); + GUEST_ASSERT_EQ(wp_data_addr, 0); + + /* OS Lock blocking single-step */ + reset_debug_state(); + enable_os_lock(); + ss_addr[0] = 0; + install_ss(); + ss_idx = 0; + asm volatile("mrs x0, esr_el1\n\t" + "add x0, x0, #1\n\t" + "msr daifset, #8\n\t" + : : : "x0"); + GUEST_ASSERT_EQ(ss_addr[0], 0); + + /* Linked hardware-breakpoint */ + hw_bp_addr = 0; + reset_debug_state(); + install_hw_bp_ctx(bpn, ctx_bpn, PC(hw_bp_ctx), ctx); + /* Set context id */ + write_sysreg(ctx, contextidr_el1); + isb(); + asm volatile("hw_bp_ctx: nop"); + write_sysreg(0, contextidr_el1); + GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp_ctx)); + + /* Linked watchpoint */ + reset_debug_state(); + install_wp_ctx(wpn, ctx_bpn, PC(write_data), ctx); + /* Set context id */ + write_sysreg(ctx, contextidr_el1); + isb(); + write_data = 'x'; + GUEST_ASSERT_EQ(write_data, 'x'); + GUEST_ASSERT_EQ(wp_data_addr, PC(write_data)); + + GUEST_DONE(); +} + +static void guest_sw_bp_handler(struct ex_regs *regs) +{ + sw_bp_addr = regs->pc; + regs->pc += 4; +} + +static void guest_hw_bp_handler(struct ex_regs *regs) +{ + hw_bp_addr = regs->pc; + regs->pstate |= SPSR_D; +} + +static void guest_wp_handler(struct ex_regs *regs) +{ + wp_data_addr = read_sysreg(far_el1); + wp_addr = regs->pc; + regs->pstate |= SPSR_D; +} + +static void guest_ss_handler(struct ex_regs *regs) +{ + __GUEST_ASSERT(ss_idx < 4, "Expected index < 4, got '%u'", ss_idx); + ss_addr[ss_idx++] = regs->pc; + regs->pstate |= SPSR_SS; +} + +static void guest_svc_handler(struct ex_regs *regs) +{ + svc_addr = regs->pc; +} + +static void guest_code_ss(int test_cnt) +{ + uint64_t i; + uint64_t bvr, wvr, w_bvr, w_wvr; + + for (i = 0; i < test_cnt; i++) { + /* Bits [1:0] of dbg{b,w}vr are RES0 */ + w_bvr = i << 2; + w_wvr = i << 2; + + /* + * Enable Single Step execution. Note! This _must_ be a bare + * ucall as the ucall() path uses atomic operations to manage + * the ucall structures, and the built-in "atomics" are usually + * implemented via exclusive access instructions. The exlusive + * monitor is cleared on ERET, and so taking debug exceptions + * during a LDREX=>STREX sequence will prevent forward progress + * and hang the guest/test. + */ + GUEST_UCALL_NONE(); + + /* + * The userspace will verify that the pc is as expected during + * single step execution between iter_ss_begin and iter_ss_end. + */ + asm volatile("iter_ss_begin:nop\n"); + + write_sysreg(w_bvr, dbgbvr0_el1); + write_sysreg(w_wvr, dbgwvr0_el1); + bvr = read_sysreg(dbgbvr0_el1); + wvr = read_sysreg(dbgwvr0_el1); + + /* Userspace disables Single Step when the end is nigh. */ + asm volatile("iter_ss_end:\n"); + + GUEST_ASSERT_EQ(bvr, w_bvr); + GUEST_ASSERT_EQ(wvr, w_wvr); + } + GUEST_DONE(); +} + +static int debug_version(uint64_t id_aa64dfr0) +{ + return FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), id_aa64dfr0); +} + +static void test_guest_debug_exceptions(uint8_t bpn, uint8_t wpn, uint8_t ctx_bpn) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_BRK_INS, guest_sw_bp_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_HW_BP_CURRENT, guest_hw_bp_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_WP_CURRENT, guest_wp_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_SSTEP_CURRENT, guest_ss_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_SVC64, guest_svc_handler); + + /* Specify bpn/wpn/ctx_bpn to be tested */ + vcpu_args_set(vcpu, 3, bpn, wpn, ctx_bpn); + pr_debug("Use bpn#%d, wpn#%d and ctx_bpn#%d\n", bpn, wpn, ctx_bpn); + + vcpu_run(vcpu); + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + break; + case UCALL_DONE: + goto done; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + +done: + kvm_vm_free(vm); +} + +void test_single_step_from_userspace(int test_cnt) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + struct kvm_run *run; + uint64_t pc, cmd; + uint64_t test_pc = 0; + bool ss_enable = false; + struct kvm_guest_debug debug = {}; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code_ss); + run = vcpu->run; + vcpu_args_set(vcpu, 1, test_cnt); + + while (1) { + vcpu_run(vcpu); + if (run->exit_reason != KVM_EXIT_DEBUG) { + cmd = get_ucall(vcpu, &uc); + if (cmd == UCALL_ABORT) { + REPORT_GUEST_ASSERT(uc); + /* NOT REACHED */ + } else if (cmd == UCALL_DONE) { + break; + } + + TEST_ASSERT(cmd == UCALL_NONE, + "Unexpected ucall cmd 0x%lx", cmd); + + debug.control = KVM_GUESTDBG_ENABLE | + KVM_GUESTDBG_SINGLESTEP; + ss_enable = true; + vcpu_guest_debug_set(vcpu, &debug); + continue; + } + + TEST_ASSERT(ss_enable, "Unexpected KVM_EXIT_DEBUG"); + + /* Check if the current pc is expected. */ + vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pc), &pc); + TEST_ASSERT(!test_pc || pc == test_pc, + "Unexpected pc 0x%lx (expected 0x%lx)", + pc, test_pc); + + if ((pc + 4) == (uint64_t)&iter_ss_end) { + test_pc = 0; + debug.control = KVM_GUESTDBG_ENABLE; + ss_enable = false; + vcpu_guest_debug_set(vcpu, &debug); + continue; + } + + /* + * If the current pc is between iter_ss_bgin and + * iter_ss_end, the pc for the next KVM_EXIT_DEBUG should + * be the current pc + 4. + */ + if ((pc >= (uint64_t)&iter_ss_begin) && + (pc < (uint64_t)&iter_ss_end)) + test_pc = pc + 4; + else + test_pc = 0; + } + + kvm_vm_free(vm); +} + +/* + * Run debug testing using the various breakpoint#, watchpoint# and + * context-aware breakpoint# with the given ID_AA64DFR0_EL1 configuration. + */ +void test_guest_debug_exceptions_all(uint64_t aa64dfr0) +{ + uint8_t brp_num, wrp_num, ctx_brp_num, normal_brp_num, ctx_brp_base; + int b, w, c; + + /* Number of breakpoints */ + brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_BRPS), aa64dfr0) + 1; + __TEST_REQUIRE(brp_num >= 2, "At least two breakpoints are required"); + + /* Number of watchpoints */ + wrp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_WRPS), aa64dfr0) + 1; + + /* Number of context aware breakpoints */ + ctx_brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_CTX_CMPS), aa64dfr0) + 1; + + pr_debug("%s brp_num:%d, wrp_num:%d, ctx_brp_num:%d\n", __func__, + brp_num, wrp_num, ctx_brp_num); + + /* Number of normal (non-context aware) breakpoints */ + normal_brp_num = brp_num - ctx_brp_num; + + /* Lowest context aware breakpoint number */ + ctx_brp_base = normal_brp_num; + + /* Run tests with all supported breakpoints/watchpoints */ + for (c = ctx_brp_base; c < ctx_brp_base + ctx_brp_num; c++) { + for (b = 0; b < normal_brp_num; b++) { + for (w = 0; w < wrp_num; w++) + test_guest_debug_exceptions(b, w, c); + } + } +} + +static void help(char *name) +{ + puts(""); + printf("Usage: %s [-h] [-i iterations of the single step test]\n", name); + puts(""); + exit(0); +} + +int main(int argc, char *argv[]) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + int opt; + int ss_iteration = 10000; + uint64_t aa64dfr0; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &aa64dfr0); + __TEST_REQUIRE(debug_version(aa64dfr0) >= 6, + "Armv8 debug architecture not supported."); + kvm_vm_free(vm); + + while ((opt = getopt(argc, argv, "i:")) != -1) { + switch (opt) { + case 'i': + ss_iteration = atoi_positive("Number of iterations", optarg); + break; + case 'h': + default: + help(argv[0]); + break; + } + } + + test_guest_debug_exceptions_all(aa64dfr0); + test_single_step_from_userspace(ss_iteration); + + return 0; +} |