tools/testing/selftests/kvm/lib/perf_test_util.c

   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
  10 struct perf_test_args perf_test_args;
  11
  12 uint64_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  */
  18 static 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  */
  24 static 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
  51 struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
  52                                    uint64_t vcpu_memory_bytes)
  53 {
  54         struct kvm_vm *vm;
  55         uint64_t guest_num_pages;
  56
  57         pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
  58
  59         perf_test_args.host_page_size = getpagesize();
  60         perf_test_args.guest_page_size = vm_guest_mode_params[mode].page_size;
  61
  62         guest_num_pages = vm_adjust_num_guest_pages(mode,
  63                                 (vcpus * vcpu_memory_bytes) / perf_test_args.guest_page_size);
  64
  65         TEST_ASSERT(vcpu_memory_bytes % perf_test_args.host_page_size == 0,
  66                     "Guest memory size is not host page size aligned.");
  67         TEST_ASSERT(vcpu_memory_bytes % perf_test_args.guest_page_size == 0,
  68                     "Guest memory size is not guest page size aligned.");
  69
  70         vm = vm_create_with_vcpus(mode, vcpus,
  71                                   (vcpus * vcpu_memory_bytes) / perf_test_args.guest_page_size,
  72                                   0, guest_code, NULL);
  73
  74         perf_test_args.vm = vm;
  75
  76         /*
  77          * If there should be more memory in the guest test region than there
  78          * can be pages in the guest, it will definitely cause problems.
  79          */
  80         TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm),
  81                     "Requested more guest memory than address space allows.\n"
  82                     "    guest pages: %lx max gfn: %x vcpus: %d wss: %lx]\n",
  83                     guest_num_pages, vm_get_max_gfn(vm), vcpus,
  84                     vcpu_memory_bytes);
  85
  86         guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
  87                               perf_test_args.guest_page_size;
  88         guest_test_phys_mem &= ~(perf_test_args.host_page_size - 1);
  89 #ifdef __s390x__
  90         /* Align to 1M (segment size) */
  91         guest_test_phys_mem &= ~((1 << 20) - 1);
  92 #endif
  93         pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
  94
  95         /* Add an extra memory slot for testing */
  96         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
  97                                     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
 109 void perf_test_destroy_vm(struct kvm_vm *vm)
 110 {
 111         ucall_uninit(vm);
 112         kvm_vm_free(vm);
 113 }
 114
 115 void perf_test_setup_vcpus(struct kvm_vm *vm, int vcpus, uint64_t vcpu_memory_bytes)
 116 {
 117         vm_paddr_t vcpu_gpa;
 118         struct perf_test_vcpu_args *vcpu_args;
 119         int vcpu_id;
 120
 121         for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
 122                 vcpu_args = &perf_test_args.vcpu_args[vcpu_id];
 123
 124                 vcpu_args->vcpu_id = vcpu_id;
 125                 vcpu_args->gva = guest_test_virt_mem +
 126                                  (vcpu_id * vcpu_memory_bytes);
 127                 vcpu_args->pages = vcpu_memory_bytes /
 128                                    perf_test_args.guest_page_size;
 129
 130                 vcpu_gpa = guest_test_phys_mem + (vcpu_id * vcpu_memory_bytes);
 131                 pr_debug("Added VCPU %d with test mem gpa [%lx, %lx)\n",
 132                          vcpu_id, vcpu_gpa, vcpu_gpa + vcpu_memory_bytes);
 133         }
 134 }