diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c | 122 |
1 files changed, 48 insertions, 74 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c b/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c index e0004bd26536..32f7e09ef67c 100644 --- a/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c +++ b/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c @@ -17,84 +17,70 @@ /* VMCALL and VMMCALL are both 3-byte opcodes. */ #define HYPERCALL_INSN_SIZE 3 -static bool ud_expected; +static bool quirk_disabled; static void guest_ud_handler(struct ex_regs *regs) { - GUEST_ASSERT(ud_expected); - GUEST_DONE(); + regs->rax = -EFAULT; + regs->rip += HYPERCALL_INSN_SIZE; } -extern uint8_t svm_hypercall_insn[HYPERCALL_INSN_SIZE]; -static uint64_t svm_do_sched_yield(uint8_t apic_id) -{ - uint64_t ret; +static const uint8_t vmx_vmcall[HYPERCALL_INSN_SIZE] = { 0x0f, 0x01, 0xc1 }; +static const uint8_t svm_vmmcall[HYPERCALL_INSN_SIZE] = { 0x0f, 0x01, 0xd9 }; - asm volatile("mov %1, %%rax\n\t" - "mov %2, %%rbx\n\t" - "svm_hypercall_insn:\n\t" - "vmmcall\n\t" - "mov %%rax, %0\n\t" - : "=r"(ret) - : "r"((uint64_t)KVM_HC_SCHED_YIELD), "r"((uint64_t)apic_id) - : "rax", "rbx", "memory"); - - return ret; -} - -extern uint8_t vmx_hypercall_insn[HYPERCALL_INSN_SIZE]; -static uint64_t vmx_do_sched_yield(uint8_t apic_id) +extern uint8_t hypercall_insn[HYPERCALL_INSN_SIZE]; +static uint64_t do_sched_yield(uint8_t apic_id) { uint64_t ret; - asm volatile("mov %1, %%rax\n\t" - "mov %2, %%rbx\n\t" - "vmx_hypercall_insn:\n\t" - "vmcall\n\t" - "mov %%rax, %0\n\t" - : "=r"(ret) - : "r"((uint64_t)KVM_HC_SCHED_YIELD), "r"((uint64_t)apic_id) - : "rax", "rbx", "memory"); + asm volatile("hypercall_insn:\n\t" + ".byte 0xcc,0xcc,0xcc\n\t" + : "=a"(ret) + : "a"((uint64_t)KVM_HC_SCHED_YIELD), "b"((uint64_t)apic_id) + : "memory"); return ret; } static void guest_main(void) { - uint8_t *native_hypercall_insn, *hypercall_insn; - uint8_t apic_id; - - apic_id = GET_APIC_ID_FIELD(xapic_read_reg(APIC_ID)); + const uint8_t *native_hypercall_insn; + const uint8_t *other_hypercall_insn; + uint64_t ret; if (is_intel_cpu()) { - native_hypercall_insn = vmx_hypercall_insn; - hypercall_insn = svm_hypercall_insn; - svm_do_sched_yield(apic_id); + native_hypercall_insn = vmx_vmcall; + other_hypercall_insn = svm_vmmcall; } else if (is_amd_cpu()) { - native_hypercall_insn = svm_hypercall_insn; - hypercall_insn = vmx_hypercall_insn; - vmx_do_sched_yield(apic_id); + native_hypercall_insn = svm_vmmcall; + other_hypercall_insn = vmx_vmcall; } else { GUEST_ASSERT(0); /* unreachable */ return; } + memcpy(hypercall_insn, other_hypercall_insn, HYPERCALL_INSN_SIZE); + + ret = do_sched_yield(GET_APIC_ID_FIELD(xapic_read_reg(APIC_ID))); + /* - * The hypercall didn't #UD (guest_ud_handler() signals "done" if a #UD - * occurs). Verify that a #UD is NOT expected and that KVM patched in - * the native hypercall. + * If the quirk is disabled, verify that guest_ud_handler() "returned" + * -EFAULT and that KVM did NOT patch the hypercall. If the quirk is + * enabled, verify that the hypercall succeeded and that KVM patched in + * the "right" hypercall. */ - GUEST_ASSERT(!ud_expected); - GUEST_ASSERT(!memcmp(native_hypercall_insn, hypercall_insn, HYPERCALL_INSN_SIZE)); - GUEST_DONE(); -} + if (quirk_disabled) { + GUEST_ASSERT(ret == (uint64_t)-EFAULT); + GUEST_ASSERT(!memcmp(other_hypercall_insn, hypercall_insn, + HYPERCALL_INSN_SIZE)); + } else { + GUEST_ASSERT(!ret); + GUEST_ASSERT(!memcmp(native_hypercall_insn, hypercall_insn, + HYPERCALL_INSN_SIZE)); + } -static void setup_ud_vector(struct kvm_vcpu *vcpu) -{ - vm_init_descriptor_tables(vcpu->vm); - vcpu_init_descriptor_tables(vcpu); - vm_install_exception_handler(vcpu->vm, UD_VECTOR, guest_ud_handler); + GUEST_DONE(); } static void enter_guest(struct kvm_vcpu *vcpu) @@ -117,35 +103,23 @@ static void enter_guest(struct kvm_vcpu *vcpu) } } -static void test_fix_hypercall(void) +static void test_fix_hypercall(bool disable_quirk) { struct kvm_vcpu *vcpu; struct kvm_vm *vm; vm = vm_create_with_one_vcpu(&vcpu, guest_main); - setup_ud_vector(vcpu); - - ud_expected = false; - sync_global_to_guest(vm, ud_expected); - - virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA); - - enter_guest(vcpu); -} -static void test_fix_hypercall_disabled(void) -{ - struct kvm_vcpu *vcpu; - struct kvm_vm *vm; - - vm = vm_create_with_one_vcpu(&vcpu, guest_main); - setup_ud_vector(vcpu); + vm_init_descriptor_tables(vcpu->vm); + vcpu_init_descriptor_tables(vcpu); + vm_install_exception_handler(vcpu->vm, UD_VECTOR, guest_ud_handler); - vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, - KVM_X86_QUIRK_FIX_HYPERCALL_INSN); + if (disable_quirk) + vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, + KVM_X86_QUIRK_FIX_HYPERCALL_INSN); - ud_expected = true; - sync_global_to_guest(vm, ud_expected); + quirk_disabled = disable_quirk; + sync_global_to_guest(vm, quirk_disabled); virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA); @@ -156,6 +130,6 @@ int main(void) { TEST_REQUIRE(kvm_check_cap(KVM_CAP_DISABLE_QUIRKS2) & KVM_X86_QUIRK_FIX_HYPERCALL_INSN); - test_fix_hypercall(); - test_fix_hypercall_disabled(); + test_fix_hypercall(false); + test_fix_hypercall(true); } |