| // 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" |
| |
| #define VCPU_ID 0 |
| |
| /* The virtual machine object. */ |
| static struct kvm_vm *vm; |
| |
| 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; |
| unsigned int paddr_width; |
| unsigned int vaddr_width; |
| vm_vaddr_t vmx_pages_gva; |
| unsigned long high_gpa; |
| struct vmx_pages *vmx; |
| bool done = false; |
| |
| nested_vmx_check_supported(); |
| |
| vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code); |
| vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); |
| |
| kvm_get_cpu_address_width(&paddr_width, &vaddr_width); |
| high_gpa = (1ul << paddr_width) - getpagesize(); |
| if ((unsigned long)DEFAULT_GUEST_PHY_PAGES * getpagesize() > high_gpa) { |
| print_skip("No unbacked physical page available"); |
| exit(KSFT_SKIP); |
| } |
| |
| vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva); |
| prepare_virtualize_apic_accesses(vmx, vm, 0); |
| vcpu_args_set(vm, VCPU_ID, 2, vmx_pages_gva, high_gpa); |
| |
| while (!done) { |
| volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID); |
| struct ucall uc; |
| |
| vcpu_run(vm, VCPU_ID); |
| if (apic_access_addr == high_gpa) { |
| TEST_ASSERT(run->exit_reason == |
| KVM_EXIT_INTERNAL_ERROR, |
| "Got exit reason other than KVM_EXIT_INTERNAL_ERROR: %u (%s)\n", |
| run->exit_reason, |
| exit_reason_str(run->exit_reason)); |
| 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(run->exit_reason == KVM_EXIT_IO, |
| "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n", |
| run->exit_reason, |
| exit_reason_str(run->exit_reason)); |
| |
| switch (get_ucall(vm, VCPU_ID, &uc)) { |
| case UCALL_ABORT: |
| TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0], |
| __FILE__, uc.args[1]); |
| /* 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; |
| } |