From 449aa906e67e57636086967bf0edc1328fd0ca9f Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Tue, 5 May 2020 16:50:00 -0400 Subject: KVM: selftests: Add KVM_SET_GUEST_DEBUG test Covers fundamental tests for KVM_SET_GUEST_DEBUG. It is very close to the debug test in kvm-unit-test, but doing it from outside the guest. Signed-off-by: Peter Xu Message-Id: <20200505205000.188252-4-peterx@redhat.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 1 + tools/testing/selftests/kvm/include/kvm_util.h | 2 + tools/testing/selftests/kvm/lib/kvm_util.c | 9 ++ tools/testing/selftests/kvm/x86_64/debug_regs.c | 180 ++++++++++++++++++++++++ 4 files changed, 192 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/debug_regs.c (limited to 'tools') diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 712a2ddd2a27..44b6ef513164 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -28,6 +28,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test +TEST_GEN_PROGS_x86_64 += x86_64/debug_regs TEST_GEN_PROGS_x86_64 += clear_dirty_log_test TEST_GEN_PROGS_x86_64 += demand_paging_test TEST_GEN_PROGS_x86_64 += dirty_log_test diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index a99b875f50d2..92e184a422ee 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -143,6 +143,8 @@ struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid); void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid); int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid); void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid); +void vcpu_set_guest_debug(struct kvm_vm *vm, uint32_t vcpuid, + struct kvm_guest_debug *debug); void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_mp_state *mp_state); void vcpu_regs_get(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_regs *regs); diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 8a3523d4434f..9622431069bc 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1201,6 +1201,15 @@ void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid) ret, errno); } +void vcpu_set_guest_debug(struct kvm_vm *vm, uint32_t vcpuid, + struct kvm_guest_debug *debug) +{ + struct vcpu *vcpu = vcpu_find(vm, vcpuid); + int ret = ioctl(vcpu->fd, KVM_SET_GUEST_DEBUG, debug); + + TEST_ASSERT(ret == 0, "KVM_SET_GUEST_DEBUG failed: %d", ret); +} + /* * VM VCPU Set MP State * diff --git a/tools/testing/selftests/kvm/x86_64/debug_regs.c b/tools/testing/selftests/kvm/x86_64/debug_regs.c new file mode 100644 index 000000000000..077f25d61d1a --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/debug_regs.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KVM guest debug register tests + * + * Copyright (C) 2020, Red Hat, Inc. + */ +#include +#include +#include "kvm_util.h" +#include "processor.h" + +#define VCPU_ID 0 + +/* For testing data access debug BP */ +uint32_t guest_value; + +extern unsigned char sw_bp, hw_bp, write_data, ss_start; + +static void guest_code(void) +{ + /* + * Software BP tests. + * + * NOTE: sw_bp need to be before the cmd here, because int3 is an + * exception rather than a normal trap for KVM_SET_GUEST_DEBUG (we + * capture it using the vcpu exception bitmap). + */ + asm volatile("sw_bp: int3"); + + /* Hardware instruction BP test */ + asm volatile("hw_bp: nop"); + + /* Hardware data BP test */ + asm volatile("mov $1234,%%rax;\n\t" + "mov %%rax,%0;\n\t write_data:" + : "=m" (guest_value) : : "rax"); + + /* Single step test, covers 2 basic instructions and 2 emulated */ + asm volatile("ss_start: " + "xor %%rax,%%rax\n\t" + "cpuid\n\t" + "movl $0x1a0,%%ecx\n\t" + "rdmsr\n\t" + : : : "rax", "ecx"); + + GUEST_DONE(); +} + +#define CLEAR_DEBUG() memset(&debug, 0, sizeof(debug)) +#define APPLY_DEBUG() vcpu_set_guest_debug(vm, VCPU_ID, &debug) +#define CAST_TO_RIP(v) ((unsigned long long)&(v)) +#define SET_RIP(v) do { \ + vcpu_regs_get(vm, VCPU_ID, ®s); \ + regs.rip = (v); \ + vcpu_regs_set(vm, VCPU_ID, ®s); \ + } while (0) +#define MOVE_RIP(v) SET_RIP(regs.rip + (v)); + +int main(void) +{ + struct kvm_guest_debug debug; + unsigned long long target_dr6, target_rip; + struct kvm_regs regs; + struct kvm_run *run; + struct kvm_vm *vm; + struct ucall uc; + uint64_t cmd; + int i; + /* Instruction lengths starting at ss_start */ + int ss_size[4] = { + 3, /* xor */ + 2, /* cpuid */ + 5, /* mov */ + 2, /* rdmsr */ + }; + + if (!kvm_check_cap(KVM_CAP_SET_GUEST_DEBUG)) { + print_skip("KVM_CAP_SET_GUEST_DEBUG not supported"); + return 0; + } + + vm = vm_create_default(VCPU_ID, 0, guest_code); + vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); + run = vcpu_state(vm, VCPU_ID); + + /* Test software BPs - int3 */ + CLEAR_DEBUG(); + debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP; + APPLY_DEBUG(); + vcpu_run(vm, VCPU_ID); + TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG && + run->debug.arch.exception == BP_VECTOR && + run->debug.arch.pc == CAST_TO_RIP(sw_bp), + "INT3: exit %d exception %d rip 0x%llx (should be 0x%llx)", + run->exit_reason, run->debug.arch.exception, + run->debug.arch.pc, CAST_TO_RIP(sw_bp)); + MOVE_RIP(1); + + /* Test instruction HW BP over DR[0-3] */ + for (i = 0; i < 4; i++) { + CLEAR_DEBUG(); + debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP; + debug.arch.debugreg[i] = CAST_TO_RIP(hw_bp); + debug.arch.debugreg[7] = 0x400 | (1UL << (2*i+1)); + APPLY_DEBUG(); + vcpu_run(vm, VCPU_ID); + target_dr6 = 0xffff0ff0 | (1UL << i); + TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG && + run->debug.arch.exception == DB_VECTOR && + run->debug.arch.pc == CAST_TO_RIP(hw_bp) && + run->debug.arch.dr6 == target_dr6, + "INS_HW_BP (DR%d): exit %d exception %d rip 0x%llx " + "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)", + i, run->exit_reason, run->debug.arch.exception, + run->debug.arch.pc, CAST_TO_RIP(hw_bp), + run->debug.arch.dr6, target_dr6); + } + /* Skip "nop" */ + MOVE_RIP(1); + + /* Test data access HW BP over DR[0-3] */ + for (i = 0; i < 4; i++) { + CLEAR_DEBUG(); + debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP; + debug.arch.debugreg[i] = CAST_TO_RIP(guest_value); + debug.arch.debugreg[7] = 0x00000400 | (1UL << (2*i+1)) | + (0x000d0000UL << (4*i)); + APPLY_DEBUG(); + vcpu_run(vm, VCPU_ID); + target_dr6 = 0xffff0ff0 | (1UL << i); + TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG && + run->debug.arch.exception == DB_VECTOR && + run->debug.arch.pc == CAST_TO_RIP(write_data) && + run->debug.arch.dr6 == target_dr6, + "DATA_HW_BP (DR%d): exit %d exception %d rip 0x%llx " + "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)", + i, run->exit_reason, run->debug.arch.exception, + run->debug.arch.pc, CAST_TO_RIP(write_data), + run->debug.arch.dr6, target_dr6); + /* Rollback the 4-bytes "mov" */ + MOVE_RIP(-7); + } + /* Skip the 4-bytes "mov" */ + MOVE_RIP(7); + + /* Test single step */ + target_rip = CAST_TO_RIP(ss_start); + target_dr6 = 0xffff4ff0ULL; + vcpu_regs_get(vm, VCPU_ID, ®s); + for (i = 0; i < (sizeof(ss_size) / sizeof(ss_size[0])); i++) { + target_rip += ss_size[i]; + CLEAR_DEBUG(); + debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP; + debug.arch.debugreg[7] = 0x00000400; + APPLY_DEBUG(); + vcpu_run(vm, VCPU_ID); + TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG && + run->debug.arch.exception == DB_VECTOR && + run->debug.arch.pc == target_rip && + run->debug.arch.dr6 == target_dr6, + "SINGLE_STEP[%d]: exit %d exception %d rip 0x%llx " + "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)", + i, run->exit_reason, run->debug.arch.exception, + run->debug.arch.pc, target_rip, run->debug.arch.dr6, + target_dr6); + } + + /* Disable all debug controls, run to the end */ + CLEAR_DEBUG(); + APPLY_DEBUG(); + + vcpu_run(vm, VCPU_ID); + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, "KVM_EXIT_IO"); + cmd = get_ucall(vm, VCPU_ID, &uc); + TEST_ASSERT(cmd == UCALL_DONE, "UCALL_DONE"); + + kvm_vm_free(vm); + + return 0; +} -- cgit v1.2.3