Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
21static void guest_code(bool tdp_enabled)
22{
23 u64 error_code;
24 u64 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
45int main(int argc, char *argv[])
46{
47 struct kvm_vcpu *vcpu;
48 struct kvm_vm *vm;
49 struct ucall uc;
50 u64 *hva;
51 gpa_t gpa;
52 int rc;
53
54 TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR));
55
56 vm = vm_create_with_one_vcpu(&vcpu, guest_code);
57 vcpu_args_set(vcpu, 1, kvm_is_tdp_enabled());
58
59 vcpu_set_cpuid_property(vcpu, X86_PROPERTY_MAX_PHY_ADDR, MAXPHYADDR);
60
61 rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE);
62 TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable");
63 vm_enable_cap(vm, KVM_CAP_EXIT_ON_EMULATION_FAILURE, 1);
64
65 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
66 MEM_REGION_GPA, MEM_REGION_SLOT,
67 MEM_REGION_SIZE / PAGE_SIZE, 0);
68 gpa = vm_phy_pages_alloc(vm, MEM_REGION_SIZE / PAGE_SIZE,
69 MEM_REGION_GPA, MEM_REGION_SLOT);
70 TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc");
71 virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1);
72 hva = addr_gpa2hva(vm, MEM_REGION_GPA);
73 memset(hva, 0, PAGE_SIZE);
74
75 *vm_get_pte(vm, MEM_REGION_GVA) |= BIT_ULL(MAXPHYADDR);
76
77 vcpu_run(vcpu);
78
79 /*
80 * When TDP is enabled, KVM must emulate in response the guest physical
81 * address that is illegal from the guest's perspective, but is legal
82 * from hardware's perspeective. This should result in an emulation
83 * failure exit to userspace since KVM doesn't support emulating flds.
84 */
85 if (kvm_is_tdp_enabled()) {
86 handle_flds_emulation_failure_exit(vcpu);
87 vcpu_run(vcpu);
88 }
89
90 switch (get_ucall(vcpu, &uc)) {
91 case UCALL_ABORT:
92 REPORT_GUEST_ASSERT(uc);
93 break;
94 case UCALL_DONE:
95 break;
96 default:
97 TEST_FAIL("Unrecognized ucall: %lu", uc.cmd);
98 }
99
100 kvm_vm_free(vm);
101
102 return 0;
103}