diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c b/tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c new file mode 100644 index 0000000000..2bed5fb3a0 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/vmx_apic_access_test.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vmx_apic_access_test + * + * Copyright (C) 2020, Google LLC. + * + * This work is licensed under the terms of the GNU GPL, version 2. + * + * The first subtest simply checks to see that an L2 guest can be + * launched with a valid APIC-access address that is backed by a + * page of L1 physical memory. + * + * The second subtest sets the APIC-access address to a (valid) L1 + * physical address that is not backed by memory. KVM can't handle + * this situation, so resuming L2 should result in a KVM exit for + * internal error (emulation). This is not an architectural + * requirement. It is just a shortcoming of KVM. The internal error + * is unfortunate, but it's better than what used to happen! + */ + +#include "test_util.h" +#include "kvm_util.h" +#include "processor.h" +#include "vmx.h" + +#include <string.h> +#include <sys/ioctl.h> + +#include "kselftest.h" + +static void l2_guest_code(void) +{ + /* Exit to L1 */ + __asm__ __volatile__("vmcall"); +} + +static void l1_guest_code(struct vmx_pages *vmx_pages, unsigned long high_gpa) +{ +#define L2_GUEST_STACK_SIZE 64 + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + uint32_t control; + + GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); + GUEST_ASSERT(load_vmcs(vmx_pages)); + + /* Prepare the VMCS for L2 execution. */ + prepare_vmcs(vmx_pages, l2_guest_code, + &l2_guest_stack[L2_GUEST_STACK_SIZE]); + control = vmreadz(CPU_BASED_VM_EXEC_CONTROL); + control |= CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; + vmwrite(CPU_BASED_VM_EXEC_CONTROL, control); + control = vmreadz(SECONDARY_VM_EXEC_CONTROL); + control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; + vmwrite(SECONDARY_VM_EXEC_CONTROL, control); + vmwrite(APIC_ACCESS_ADDR, vmx_pages->apic_access_gpa); + + /* Try to launch L2 with the memory-backed APIC-access address. */ + GUEST_SYNC(vmreadz(APIC_ACCESS_ADDR)); + GUEST_ASSERT(!vmlaunch()); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); + + vmwrite(APIC_ACCESS_ADDR, high_gpa); + + /* Try to resume L2 with the unbacked APIC-access address. */ + GUEST_SYNC(vmreadz(APIC_ACCESS_ADDR)); + GUEST_ASSERT(!vmresume()); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); + + GUEST_DONE(); +} + +int main(int argc, char *argv[]) +{ + unsigned long apic_access_addr = ~0ul; + vm_vaddr_t vmx_pages_gva; + unsigned long high_gpa; + struct vmx_pages *vmx; + bool done = false; + + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX)); + + vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code); + + high_gpa = (vm->max_gfn - 1) << vm->page_shift; + + vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva); + prepare_virtualize_apic_accesses(vmx, vm); + vcpu_args_set(vcpu, 2, vmx_pages_gva, high_gpa); + + while (!done) { + volatile struct kvm_run *run = vcpu->run; + struct ucall uc; + + vcpu_run(vcpu); + if (apic_access_addr == high_gpa) { + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR); + TEST_ASSERT(run->internal.suberror == + KVM_INTERNAL_ERROR_EMULATION, + "Got internal suberror other than KVM_INTERNAL_ERROR_EMULATION: %u\n", + run->internal.suberror); + break; + } + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + /* NOT REACHED */ + case UCALL_SYNC: + apic_access_addr = uc.args[1]; + break; + case UCALL_DONE: + done = true; + break; + default: + TEST_ASSERT(false, "Unknown ucall %lu", uc.cmd); + } + } + kvm_vm_free(vm); + return 0; +} |