1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * x86-specific extensions to memstress.c.
4 *
5 * Copyright (C) 2022, Google, Inc.
6 */
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <linux/bitmap.h>
10 #include <linux/bitops.h>
11
12 #include "test_util.h"
13 #include "kvm_util.h"
14 #include "memstress.h"
15 #include "processor.h"
16 #include "svm_util.h"
17 #include "vmx.h"
18
memstress_l2_guest_code(u64 vcpu_id)19 void memstress_l2_guest_code(u64 vcpu_id)
20 {
21 memstress_guest_code(vcpu_id);
22 vmcall();
23 }
24
25 extern char memstress_l2_guest_entry[];
26 __asm__(
27 "memstress_l2_guest_entry:"
28 " mov (%rsp), %rdi;"
29 " call memstress_l2_guest_code;"
30 " ud2;"
31 );
32
33 #define L2_GUEST_STACK_SIZE 64
34
l1_vmx_code(struct vmx_pages * vmx,u64 vcpu_id)35 static void l1_vmx_code(struct vmx_pages *vmx, u64 vcpu_id)
36 {
37 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
38 unsigned long *rsp;
39
40 GUEST_ASSERT(vmx->vmcs_gpa);
41 GUEST_ASSERT(prepare_for_vmx_operation(vmx));
42 GUEST_ASSERT(load_vmcs(vmx));
43 GUEST_ASSERT(ept_1g_pages_supported());
44
45 rsp = &l2_guest_stack[L2_GUEST_STACK_SIZE - 1];
46 *rsp = vcpu_id;
47 prepare_vmcs(vmx, memstress_l2_guest_entry, rsp);
48
49 GUEST_ASSERT(!vmlaunch());
50 GUEST_ASSERT_EQ(vmreadz(VM_EXIT_REASON), EXIT_REASON_VMCALL);
51 GUEST_DONE();
52 }
53
l1_svm_code(struct svm_test_data * svm,u64 vcpu_id)54 static void l1_svm_code(struct svm_test_data *svm, u64 vcpu_id)
55 {
56 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
57 unsigned long *rsp;
58
59
60 rsp = &l2_guest_stack[L2_GUEST_STACK_SIZE - 1];
61 *rsp = vcpu_id;
62 generic_svm_setup(svm, memstress_l2_guest_entry, rsp);
63
64 run_guest(svm->vmcb, svm->vmcb_gpa);
65 GUEST_ASSERT_EQ(svm->vmcb->control.exit_code, SVM_EXIT_VMMCALL);
66 GUEST_DONE();
67 }
68
69
memstress_l1_guest_code(void * data,u64 vcpu_id)70 static void memstress_l1_guest_code(void *data, u64 vcpu_id)
71 {
72 if (this_cpu_has(X86_FEATURE_VMX))
73 l1_vmx_code(data, vcpu_id);
74 else
75 l1_svm_code(data, vcpu_id);
76 }
77
memstress_nested_pages(int nr_vcpus)78 u64 memstress_nested_pages(int nr_vcpus)
79 {
80 /*
81 * 513 page tables is enough to identity-map 256 TiB of L2 with 1G
82 * pages and 4-level paging, plus a few pages per-vCPU for data
83 * structures such as the VMCS.
84 */
85 return 513 + 10 * nr_vcpus;
86 }
87
memstress_setup_ept_mappings(struct kvm_vm * vm)88 static void memstress_setup_ept_mappings(struct kvm_vm *vm)
89 {
90 u64 start, end;
91
92 /*
93 * Identity map the first 4G and the test region with 1G pages so that
94 * KVM can shadow the EPT12 with the maximum huge page size supported
95 * by the backing source.
96 */
97 tdp_identity_map_1g(vm, 0, 0x100000000ULL);
98
99 start = align_down(memstress_args.gpa, PG_SIZE_1G);
100 end = align_up(memstress_args.gpa + memstress_args.size, PG_SIZE_1G);
101 tdp_identity_map_1g(vm, start, end - start);
102 }
103
memstress_setup_nested(struct kvm_vm * vm,int nr_vcpus,struct kvm_vcpu * vcpus[])104 void memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vcpus[])
105 {
106 struct kvm_regs regs;
107 gva_t nested_gva;
108 int vcpu_id;
109
110 TEST_REQUIRE(kvm_cpu_has_tdp());
111
112 vm_enable_tdp(vm);
113 memstress_setup_ept_mappings(vm);
114 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
115 if (kvm_cpu_has(X86_FEATURE_VMX))
116 vcpu_alloc_vmx(vm, &nested_gva);
117 else
118 vcpu_alloc_svm(vm, &nested_gva);
119
120 /*
121 * Override the vCPU to run memstress_l1_guest_code() which will
122 * bounce it into L2 before calling memstress_guest_code().
123 */
124 vcpu_regs_get(vcpus[vcpu_id], ®s);
125 regs.rip = (unsigned long) memstress_l1_guest_code;
126 vcpu_regs_set(vcpus[vcpu_id], ®s);
127 vcpu_args_set(vcpus[vcpu_id], 2, nested_gva, vcpu_id);
128 }
129 }
130