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Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/emulator_error_test.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c new file mode 100644 index 000000000000..236e11755ba6 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c @@ -0,0 +1,193 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020, Google LLC. + * + * Tests for KVM_CAP_EXIT_ON_EMULATION_FAILURE capability. + */ + +#define _GNU_SOURCE /* for program_invocation_short_name */ + +#include "test_util.h" +#include "kvm_util.h" +#include "vmx.h" + +#define MAXPHYADDR 36 + +#define MEM_REGION_GVA 0x0000123456789000 +#define MEM_REGION_GPA 0x0000000700000000 +#define MEM_REGION_SLOT 10 +#define MEM_REGION_SIZE PAGE_SIZE + +static void guest_code(void) +{ + __asm__ __volatile__("flds (%[addr])" + :: [addr]"r"(MEM_REGION_GVA)); + + GUEST_DONE(); +} + +/* + * Accessors to get R/M, REG, and Mod bits described in the SDM vol 2, + * figure 2-2 "Table Interpretation of ModR/M Byte (C8H)". + */ +#define GET_RM(insn_byte) (insn_byte & 0x7) +#define GET_REG(insn_byte) ((insn_byte & 0x38) >> 3) +#define GET_MOD(insn_byte) ((insn_byte & 0xc) >> 6) + +/* Ensure we are dealing with a simple 2-byte flds instruction. */ +static bool is_flds(uint8_t *insn_bytes, uint8_t insn_size) +{ + return insn_size >= 2 && + insn_bytes[0] == 0xd9 && + GET_REG(insn_bytes[1]) == 0x0 && + GET_MOD(insn_bytes[1]) == 0x0 && + /* Ensure there is no SIB byte. */ + GET_RM(insn_bytes[1]) != 0x4 && + /* Ensure there is no displacement byte. */ + GET_RM(insn_bytes[1]) != 0x5; +} + +static void process_exit_on_emulation_error(struct kvm_vcpu *vcpu) +{ + struct kvm_run *run = vcpu->run; + struct kvm_regs regs; + uint8_t *insn_bytes; + uint8_t insn_size; + uint64_t flags; + + TEST_ASSERT(run->exit_reason == KVM_EXIT_INTERNAL_ERROR, + "Unexpected exit reason: %u (%s)", + run->exit_reason, + exit_reason_str(run->exit_reason)); + + TEST_ASSERT(run->emulation_failure.suberror == KVM_INTERNAL_ERROR_EMULATION, + "Unexpected suberror: %u", + run->emulation_failure.suberror); + + if (run->emulation_failure.ndata >= 1) { + flags = run->emulation_failure.flags; + if ((flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES) && + run->emulation_failure.ndata >= 3) { + insn_size = run->emulation_failure.insn_size; + insn_bytes = run->emulation_failure.insn_bytes; + + TEST_ASSERT(insn_size <= 15 && insn_size > 0, + "Unexpected instruction size: %u", + insn_size); + + TEST_ASSERT(is_flds(insn_bytes, insn_size), + "Unexpected instruction. Expected 'flds' (0xd9 /0)"); + + /* + * If is_flds() succeeded then the instruction bytes + * contained an flds instruction that is 2-bytes in + * length (ie: no prefix, no SIB, no displacement). + */ + vcpu_regs_get(vcpu, ®s); + regs.rip += 2; + vcpu_regs_set(vcpu, ®s); + } + } +} + +static void do_guest_assert(struct ucall *uc) +{ + REPORT_GUEST_ASSERT(*uc); +} + +static void check_for_guest_assert(struct kvm_vcpu *vcpu) +{ + struct ucall uc; + + if (vcpu->run->exit_reason == KVM_EXIT_IO && + get_ucall(vcpu, &uc) == UCALL_ABORT) { + do_guest_assert(&uc); + } +} + +static void process_ucall_done(struct kvm_vcpu *vcpu) +{ + struct kvm_run *run = vcpu->run; + struct ucall uc; + + check_for_guest_assert(vcpu); + + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, + "Unexpected exit reason: %u (%s)", + run->exit_reason, + exit_reason_str(run->exit_reason)); + + TEST_ASSERT(get_ucall(vcpu, &uc) == UCALL_DONE, + "Unexpected ucall command: %lu, expected UCALL_DONE (%d)", + uc.cmd, UCALL_DONE); +} + +static uint64_t process_ucall(struct kvm_vcpu *vcpu) +{ + struct kvm_run *run = vcpu->run; + struct ucall uc; + + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, + "Unexpected exit reason: %u (%s)", + run->exit_reason, + exit_reason_str(run->exit_reason)); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_SYNC: + break; + case UCALL_ABORT: + do_guest_assert(&uc); + break; + case UCALL_DONE: + process_ucall_done(vcpu); + break; + default: + TEST_ASSERT(false, "Unexpected ucall"); + } + + return uc.cmd; +} + +int main(int argc, char *argv[]) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + uint64_t gpa, pte; + uint64_t *hva; + int rc; + + /* Tell stdout not to buffer its content */ + setbuf(stdout, NULL); + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR)); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + vcpu_set_cpuid_maxphyaddr(vcpu, MAXPHYADDR); + + rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE); + TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable"); + vm_enable_cap(vm, KVM_CAP_EXIT_ON_EMULATION_FAILURE, 1); + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + MEM_REGION_GPA, MEM_REGION_SLOT, + MEM_REGION_SIZE / PAGE_SIZE, 0); + gpa = vm_phy_pages_alloc(vm, MEM_REGION_SIZE / PAGE_SIZE, + MEM_REGION_GPA, MEM_REGION_SLOT); + TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc\n"); + virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1); + hva = addr_gpa2hva(vm, MEM_REGION_GPA); + memset(hva, 0, PAGE_SIZE); + pte = vm_get_page_table_entry(vm, vcpu, MEM_REGION_GVA); + vm_set_page_table_entry(vm, vcpu, MEM_REGION_GVA, pte | (1ull << 36)); + + vcpu_run(vcpu); + process_exit_on_emulation_error(vcpu); + vcpu_run(vcpu); + + TEST_ASSERT(process_ucall(vcpu) == UCALL_DONE, "Expected UCALL_DONE"); + + kvm_vm_free(vm); + + return 0; +} |