tjh.dev
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
6#include "kvm_util.h"
7#include "perf_test_util.h"
8#include "processor.h"
9
10struct perf_test_args perf_test_args;
11
12uint64_t guest_test_phys_mem;
13
14/*
15 * Guest virtual memory offset of the testing memory slot.
16 * Must not conflict with identity mapped test code.
17 */
18static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
19
20/*
21 * Continuously write to the first 8 bytes of each page in the
22 * specified region.
23 */
24static void guest_code(uint32_t vcpu_id)
25{
26 struct perf_test_vcpu_args *vcpu_args = &perf_test_args.vcpu_args[vcpu_id];
27 uint64_t gva;
28 uint64_t pages;
29 int i;
30
31 /* Make sure vCPU args data structure is not corrupt. */
32 GUEST_ASSERT(vcpu_args->vcpu_id == vcpu_id);
33
34 gva = vcpu_args->gva;
35 pages = vcpu_args->pages;
36
37 while (true) {
38 for (i = 0; i < pages; i++) {
39 uint64_t addr = gva + (i * perf_test_args.guest_page_size);
40
41 if (i % perf_test_args.wr_fract == 0)
42 *(uint64_t *)addr = 0x0123456789ABCDEF;
43 else
44 READ_ONCE(*(uint64_t *)addr);
45 }
46
47 GUEST_SYNC(1);
48 }
49}
50
51struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
52 uint64_t vcpu_memory_bytes,
53 enum vm_mem_backing_src_type backing_src)
54{
55 struct kvm_vm *vm;
56 uint64_t guest_num_pages;
57
58 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
59
60 perf_test_args.host_page_size = getpagesize();
61 perf_test_args.guest_page_size = vm_guest_mode_params[mode].page_size;
62
63 guest_num_pages = vm_adjust_num_guest_pages(mode,
64 (vcpus * vcpu_memory_bytes) / perf_test_args.guest_page_size);
65
66 TEST_ASSERT(vcpu_memory_bytes % perf_test_args.host_page_size == 0,
67 "Guest memory size is not host page size aligned.");
68 TEST_ASSERT(vcpu_memory_bytes % perf_test_args.guest_page_size == 0,
69 "Guest memory size is not guest page size aligned.");
70
71 vm = vm_create_with_vcpus(mode, vcpus,
72 (vcpus * vcpu_memory_bytes) / perf_test_args.guest_page_size,
73 0, guest_code, NULL);
74
75 perf_test_args.vm = vm;
76
77 /*
78 * If there should be more memory in the guest test region than there
79 * can be pages in the guest, it will definitely cause problems.
80 */
81 TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm),
82 "Requested more guest memory than address space allows.\n"
83 " guest pages: %lx max gfn: %x vcpus: %d wss: %lx]\n",
84 guest_num_pages, vm_get_max_gfn(vm), vcpus,
85 vcpu_memory_bytes);
86
87 guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
88 perf_test_args.guest_page_size;
89 guest_test_phys_mem &= ~(perf_test_args.host_page_size - 1);
90#ifdef __s390x__
91 /* Align to 1M (segment size) */
92 guest_test_phys_mem &= ~((1 << 20) - 1);
93#endif
94 pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
95
96 /* Add an extra memory slot for testing */
97 vm_userspace_mem_region_add(vm, backing_src, guest_test_phys_mem,
98 PERF_TEST_MEM_SLOT_INDEX,
99 guest_num_pages, 0);
100
101 /* Do mapping for the demand paging memory slot */
102 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
103
104 ucall_init(vm, NULL);
105
106 return vm;
107}
108
109void perf_test_destroy_vm(struct kvm_vm *vm)
110{
111 ucall_uninit(vm);
112 kvm_vm_free(vm);
113}
114
115void perf_test_setup_vcpus(struct kvm_vm *vm, int vcpus,
116 uint64_t vcpu_memory_bytes,
117 bool partition_vcpu_memory_access)
118{
119 vm_paddr_t vcpu_gpa;
120 struct perf_test_vcpu_args *vcpu_args;
121 int vcpu_id;
122
123 for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
124 vcpu_args = &perf_test_args.vcpu_args[vcpu_id];
125
126 vcpu_args->vcpu_id = vcpu_id;
127 if (partition_vcpu_memory_access) {
128 vcpu_args->gva = guest_test_virt_mem +
129 (vcpu_id * vcpu_memory_bytes);
130 vcpu_args->pages = vcpu_memory_bytes /
131 perf_test_args.guest_page_size;
132 vcpu_gpa = guest_test_phys_mem +
133 (vcpu_id * vcpu_memory_bytes);
134 } else {
135 vcpu_args->gva = guest_test_virt_mem;
136 vcpu_args->pages = (vcpus * vcpu_memory_bytes) /
137 perf_test_args.guest_page_size;
138 vcpu_gpa = guest_test_phys_mem;
139 }
140
141 pr_debug("Added VCPU %d with test mem gpa [%lx, %lx)\n",
142 vcpu_id, vcpu_gpa, vcpu_gpa +
143 (vcpu_args->pages * perf_test_args.guest_page_size));
144 }
145}