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
l2_guest_code(void)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
l1_guest_code(struct vmx_pages * vmx_pages)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
main(int argc,char * argv[])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