1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020, Google LLC.
4 *
5 * Test that KVM emulates instructions in response to EPT violations when
6 * allow_smaller_maxphyaddr is enabled and guest.MAXPHYADDR < host.MAXPHYADDR.
7 */
8
9 #define _GNU_SOURCE /* for program_invocation_short_name */
10
11 #include "flds_emulation.h"
12
13 #include "test_util.h"
14 #include "kvm_util.h"
15 #include "vmx.h"
16
17 #define MAXPHYADDR 36
18
19 #define MEM_REGION_GVA 0x0000123456789000
20 #define MEM_REGION_GPA 0x0000000700000000
21 #define MEM_REGION_SLOT 10
22 #define MEM_REGION_SIZE PAGE_SIZE
23
guest_code(bool tdp_enabled)24 static void guest_code(bool tdp_enabled)
25 {
26 uint64_t error_code;
27 uint64_t vector;
28
29 vector = kvm_asm_safe_ec(FLDS_MEM_EAX, error_code, "a"(MEM_REGION_GVA));
30
31 /*
32 * When TDP is enabled, flds will trigger an emulation failure, exit to
33 * userspace, and then the selftest host "VMM" skips the instruction.
34 *
35 * When TDP is disabled, no instruction emulation is required so flds
36 * should generate #PF(RSVD).
37 */
38 if (tdp_enabled) {
39 GUEST_ASSERT(!vector);
40 } else {
41 GUEST_ASSERT_EQ(vector, PF_VECTOR);
42 GUEST_ASSERT(error_code & PFERR_RSVD_MASK);
43 }
44
45 GUEST_DONE();
46 }
47
main(int argc,char * argv[])48 int main(int argc, char *argv[])
49 {
50 struct kvm_vcpu *vcpu;
51 struct kvm_vm *vm;
52 struct ucall uc;
53 uint64_t *pte;
54 uint64_t *hva;
55 uint64_t gpa;
56 int rc;
57
58 TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR));
59
60 vm = vm_create_with_one_vcpu(&vcpu, guest_code);
61 vcpu_args_set(vcpu, 1, kvm_is_tdp_enabled());
62
63 vm_init_descriptor_tables(vm);
64 vcpu_init_descriptor_tables(vcpu);
65
66 vcpu_set_cpuid_maxphyaddr(vcpu, MAXPHYADDR);
67
68 rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE);
69 TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable");
70 vm_enable_cap(vm, KVM_CAP_EXIT_ON_EMULATION_FAILURE, 1);
71
72 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
73 MEM_REGION_GPA, MEM_REGION_SLOT,
74 MEM_REGION_SIZE / PAGE_SIZE, 0);
75 gpa = vm_phy_pages_alloc(vm, MEM_REGION_SIZE / PAGE_SIZE,
76 MEM_REGION_GPA, MEM_REGION_SLOT);
77 TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc\n");
78 virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1);
79 hva = addr_gpa2hva(vm, MEM_REGION_GPA);
80 memset(hva, 0, PAGE_SIZE);
81
82 pte = vm_get_page_table_entry(vm, MEM_REGION_GVA);
83 *pte |= BIT_ULL(MAXPHYADDR);
84
85 vcpu_run(vcpu);
86
87 /*
88 * When TDP is enabled, KVM must emulate in response the guest physical
89 * address that is illegal from the guest's perspective, but is legal
90 * from hardware's perspeective. This should result in an emulation
91 * failure exit to userspace since KVM doesn't support emulating flds.
92 */
93 if (kvm_is_tdp_enabled()) {
94 handle_flds_emulation_failure_exit(vcpu);
95 vcpu_run(vcpu);
96 }
97
98 switch (get_ucall(vcpu, &uc)) {
99 case UCALL_ABORT:
100 REPORT_GUEST_ASSERT(uc);
101 break;
102 case UCALL_DONE:
103 break;
104 default:
105 TEST_FAIL("Unrecognized ucall: %lu\n", uc.cmd);
106 }
107
108 kvm_vm_free(vm);
109
110 return 0;
111 }
112