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Diffstat (limited to 'tools/testing/selftests/kvm/aarch64/debug-exceptions.c')
-rw-r--r--tools/testing/selftests/kvm/aarch64/debug-exceptions.c607
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 000000000000..2582c49e525a
--- /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_EL1_BRPs), dfr0);
+ for (i = 0; i <= brps; i++) {
+ write_dbgbcr(i, 0);
+ write_dbgbvr(i, 0);
+ }
+ wrps = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_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 '%lu'", 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_EL1_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_EL1_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_EL1_WRPs), aa64dfr0) + 1;
+
+ /* Number of context aware breakpoints */
+ ctx_brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_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;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.