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
24static 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
48int 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_property(vcpu, X86_PROPERTY_MAX_PHY_ADDR, 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");
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", uc.cmd);
106	}
107
108	kvm_vm_free(vm);
109
110	return 0;
111}
112