1 // SPDX-License-Identifier: GPL-2.0-only 2 #include "test_util.h" 3 #include "kvm_util.h" 4 #include "processor.h" 5 #include "vmx.h" 6 7 #include <string.h> 8 #include <sys/ioctl.h> 9 10 #include "kselftest.h" 11 12 #define VCPU_ID 0 13 #define ARBITRARY_IO_PORT 0x2000 14 15 static struct kvm_vm *vm; 16 17 static void l2_guest_code(void) 18 { 19 /* 20 * Generate an exit to L0 userspace, i.e. main(), via I/O to an 21 * arbitrary port. 22 */ 23 asm volatile("inb %%dx, %%al" 24 : : [port] "d" (ARBITRARY_IO_PORT) : "rax"); 25 } 26 27 static void l1_guest_code(struct vmx_pages *vmx_pages) 28 { 29 #define L2_GUEST_STACK_SIZE 64 30 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; 31 32 GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); 33 GUEST_ASSERT(load_vmcs(vmx_pages)); 34 35 /* Prepare the VMCS for L2 execution. */ 36 prepare_vmcs(vmx_pages, l2_guest_code, 37 &l2_guest_stack[L2_GUEST_STACK_SIZE]); 38 39 /* 40 * L2 must be run without unrestricted guest, verify that the selftests 41 * library hasn't enabled it. Because KVM selftests jump directly to 42 * 64-bit mode, unrestricted guest support isn't required. 43 */ 44 GUEST_ASSERT(!(vmreadz(CPU_BASED_VM_EXEC_CONTROL) & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) || 45 !(vmreadz(SECONDARY_VM_EXEC_CONTROL) & SECONDARY_EXEC_UNRESTRICTED_GUEST)); 46 47 GUEST_ASSERT(!vmlaunch()); 48 49 /* L2 should triple fault after main() stuffs invalid guest state. */ 50 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_TRIPLE_FAULT); 51 GUEST_DONE(); 52 } 53 54 int main(int argc, char *argv[]) 55 { 56 vm_vaddr_t vmx_pages_gva; 57 struct kvm_sregs sregs; 58 struct kvm_run *run; 59 struct ucall uc; 60 61 nested_vmx_check_supported(); 62 63 vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code); 64 65 /* Allocate VMX pages and shared descriptors (vmx_pages). */ 66 vcpu_alloc_vmx(vm, &vmx_pages_gva); 67 vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva); 68 69 vcpu_run(vm, VCPU_ID); 70 71 run = vcpu_state(vm, VCPU_ID); 72 73 /* 74 * The first exit to L0 userspace should be an I/O access from L2. 75 * Running L1 should launch L2 without triggering an exit to userspace. 76 */ 77 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, 78 "Expected KVM_EXIT_IO, got: %u (%s)\n", 79 run->exit_reason, exit_reason_str(run->exit_reason)); 80 81 TEST_ASSERT(run->io.port == ARBITRARY_IO_PORT, 82 "Expected IN from port %d from L2, got port %d", 83 ARBITRARY_IO_PORT, run->io.port); 84 85 /* 86 * Stuff invalid guest state for L2 by making TR unusuable. The next 87 * KVM_RUN should induce a TRIPLE_FAULT in L2 as KVM doesn't support 88 * emulating invalid guest state for L2. 89 */ 90 memset(&sregs, 0, sizeof(sregs)); 91 vcpu_sregs_get(vm, VCPU_ID, &sregs); 92 sregs.tr.unusable = 1; 93 vcpu_sregs_set(vm, VCPU_ID, &sregs); 94 95 vcpu_run(vm, VCPU_ID); 96 97 switch (get_ucall(vm, VCPU_ID, &uc)) { 98 case UCALL_DONE: 99 break; 100 case UCALL_ABORT: 101 TEST_FAIL("%s", (const char *)uc.args[0]); 102 default: 103 TEST_FAIL("Unexpected ucall: %lu", uc.cmd); 104 } 105 } 106