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 #include "flds_emulation.h"
9
10 #include "test_util.h"
11 #include "kvm_util.h"
12 #include "vmx.h"
13
14 #define MAXPHYADDR 36
15
16 #define MEM_REGION_GVA 0x0000123456789000
17 #define MEM_REGION_GPA 0x0000000700000000
18 #define MEM_REGION_SLOT 10
19 #define MEM_REGION_SIZE PAGE_SIZE
20
guest_code(bool tdp_enabled)21 static void guest_code(bool tdp_enabled)
22 {
23 uint64_t error_code;
24 uint64_t vector;
25
26 vector = kvm_asm_safe_ec(FLDS_MEM_EAX, error_code, "a"(MEM_REGION_GVA));
27
28 /*
29 * When TDP is enabled, flds will trigger an emulation failure, exit to
30 * userspace, and then the selftest host "VMM" skips the instruction.
31 *
32 * When TDP is disabled, no instruction emulation is required so flds
33 * should generate #PF(RSVD).
34 */
35 if (tdp_enabled) {
36 GUEST_ASSERT(!vector);
37 } else {
38 GUEST_ASSERT_EQ(vector, PF_VECTOR);
39 GUEST_ASSERT(error_code & PFERR_RSVD_MASK);
40 }
41
42 GUEST_DONE();
43 }
44
main(int argc,char * argv[])45 int main(int argc, char *argv[])
46 {
47 struct kvm_vcpu *vcpu;
48 struct kvm_vm *vm;
49 struct ucall uc;
50 uint64_t *pte;
51 uint64_t *hva;
52 uint64_t gpa;
53 int rc;
54
55 TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR));
56
57 vm = vm_create_with_one_vcpu(&vcpu, guest_code);
58 vcpu_args_set(vcpu, 1, kvm_is_tdp_enabled());
59
60 vcpu_set_cpuid_property(vcpu, X86_PROPERTY_MAX_PHY_ADDR, MAXPHYADDR);
61
62 rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE);
63 TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable");
64 vm_enable_cap(vm, KVM_CAP_EXIT_ON_EMULATION_FAILURE, 1);
65
66 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
67 MEM_REGION_GPA, MEM_REGION_SLOT,
68 MEM_REGION_SIZE / PAGE_SIZE, 0);
69 gpa = vm_phy_pages_alloc(vm, MEM_REGION_SIZE / PAGE_SIZE,
70 MEM_REGION_GPA, MEM_REGION_SLOT);
71 TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc");
72 virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1);
73 hva = addr_gpa2hva(vm, MEM_REGION_GPA);
74 memset(hva, 0, PAGE_SIZE);
75
76 pte = vm_get_page_table_entry(vm, MEM_REGION_GVA);
77 *pte |= BIT_ULL(MAXPHYADDR);
78
79 vcpu_run(vcpu);
80
81 /*
82 * When TDP is enabled, KVM must emulate in response the guest physical
83 * address that is illegal from the guest's perspective, but is legal
84 * from hardware's perspeective. This should result in an emulation
85 * failure exit to userspace since KVM doesn't support emulating flds.
86 */
87 if (kvm_is_tdp_enabled()) {
88 handle_flds_emulation_failure_exit(vcpu);
89 vcpu_run(vcpu);
90 }
91
92 switch (get_ucall(vcpu, &uc)) {
93 case UCALL_ABORT:
94 REPORT_GUEST_ASSERT(uc);
95 break;
96 case UCALL_DONE:
97 break;
98 default:
99 TEST_FAIL("Unrecognized ucall: %lu", uc.cmd);
100 }
101
102 kvm_vm_free(vm);
103
104 return 0;
105 }
106