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 ARBITRARY_IO_PORT 0x2000 13 14 static struct kvm_vm *vm; 15 16 static void l2_guest_code(void) 17 { 18 /* 19 * Generate an exit to L0 userspace, i.e. main(), via I/O to an 20 * arbitrary port. 21 */ 22 asm volatile("inb %%dx, %%al" 23 : : [port] "d" (ARBITRARY_IO_PORT) : "rax"); 24 } 25 26 static void l1_guest_code(struct vmx_pages *vmx_pages) 27 { 28 #define L2_GUEST_STACK_SIZE 64 29 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; 30 31 GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); 32 GUEST_ASSERT(load_vmcs(vmx_pages)); 33 34 /* Prepare the VMCS for L2 execution. */ 35 prepare_vmcs(vmx_pages, l2_guest_code, 36 &l2_guest_stack[L2_GUEST_STACK_SIZE]); 37 38 /* 39 * L2 must be run without unrestricted guest, verify that the selftests 40 * library hasn't enabled it. Because KVM selftests jump directly to 41 * 64-bit mode, unrestricted guest support isn't required. 42 */ 43 GUEST_ASSERT(!(vmreadz(CPU_BASED_VM_EXEC_CONTROL) & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) || 44 !(vmreadz(SECONDARY_VM_EXEC_CONTROL) & SECONDARY_EXEC_UNRESTRICTED_GUEST)); 45 46 GUEST_ASSERT(!vmlaunch()); 47 48 /* L2 should triple fault after main() stuffs invalid guest state. */ 49 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_TRIPLE_FAULT); 50 GUEST_DONE(); 51 } 52 53 int main(int argc, char *argv[]) 54 { 55 vm_vaddr_t vmx_pages_gva; 56 struct kvm_sregs sregs; 57 struct kvm_vcpu *vcpu; 58 struct kvm_run *run; 59 struct ucall uc; 60 61 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX)); 62 63 vm = vm_create_with_one_vcpu(&vcpu, 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(vcpu, 1, vmx_pages_gva); 68 69 vcpu_run(vcpu); 70 71 run = vcpu->run; 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_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); 78 79 TEST_ASSERT(run->io.port == ARBITRARY_IO_PORT, 80 "Expected IN from port %d from L2, got port %d", 81 ARBITRARY_IO_PORT, run->io.port); 82 83 /* 84 * Stuff invalid guest state for L2 by making TR unusuable. The next 85 * KVM_RUN should induce a TRIPLE_FAULT in L2 as KVM doesn't support 86 * emulating invalid guest state for L2. 87 */ 88 memset(&sregs, 0, sizeof(sregs)); 89 vcpu_sregs_get(vcpu, &sregs); 90 sregs.tr.unusable = 1; 91 vcpu_sregs_set(vcpu, &sregs); 92 93 vcpu_run(vcpu); 94 95 switch (get_ucall(vcpu, &uc)) { 96 case UCALL_DONE: 97 break; 98 case UCALL_ABORT: 99 REPORT_GUEST_ASSERT(uc); 100 default: 101 TEST_FAIL("Unexpected ucall: %lu", uc.cmd); 102 } 103 } 104