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 #include <inttypes.h>
   6
   7 #include "kvm_util.h"
   8 #include "perf_test_util.h"
   9 #include "processor.h"
  10
  11 struct perf_test_args perf_test_args;
  12
  13 uint64_t guest_test_phys_mem;
  14
  15 /*
  16  * Guest virtual memory offset of the testing memory slot.
  17  * Must not conflict with identity mapped test code.
  18  */
  19 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
  20
  21 /*
  22  * Continuously write to the first 8 bytes of each page in the
  23  * specified region.
  24  */
  25 static void guest_code(uint32_t vcpu_id)
  26 {
  27         struct perf_test_vcpu_args *vcpu_args = &perf_test_args.vcpu_args[vcpu_id];
  28         uint64_t gva;
  29         uint64_t pages;
  30         int i;
  31
  32         /* Make sure vCPU args data structure is not corrupt. */
  33         GUEST_ASSERT(vcpu_args->vcpu_id == vcpu_id);
  34
  35         gva = vcpu_args->gva;
  36         pages = vcpu_args->pages;
  37
  38         while (true) {
  39                 for (i = 0; i < pages; i++) {
  40                         uint64_t addr = gva + (i * perf_test_args.guest_page_size);
  41
  42                         if (i % perf_test_args.wr_fract == 0)
  43                                 *(uint64_t *)addr = 0x0123456789ABCDEF;
  44                         else
  45                                 READ_ONCE(*(uint64_t *)addr);
  46                 }
  47
  48                 GUEST_SYNC(1);
  49         }
  50 }
  51
  52 struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
  53                                    uint64_t vcpu_memory_bytes,
  54                                    enum vm_mem_backing_src_type backing_src)
  55 {
  56         struct kvm_vm *vm;
  57         uint64_t guest_num_pages;
  58
  59         pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
  60
  61         perf_test_args.host_page_size = getpagesize();
  62         perf_test_args.guest_page_size = vm_guest_mode_params[mode].page_size;
  63
  64         guest_num_pages = vm_adjust_num_guest_pages(mode,
  65                                 (vcpus * vcpu_memory_bytes) / perf_test_args.guest_page_size);
  66
  67         TEST_ASSERT(vcpu_memory_bytes % perf_test_args.host_page_size == 0,
  68                     "Guest memory size is not host page size aligned.");
  69         TEST_ASSERT(vcpu_memory_bytes % perf_test_args.guest_page_size == 0,
  70                     "Guest memory size is not guest page size aligned.");
  71
  72         vm = vm_create_with_vcpus(mode, vcpus, DEFAULT_GUEST_PHY_PAGES,
  73                                   (vcpus * vcpu_memory_bytes) / perf_test_args.guest_page_size,
  74                                   0, guest_code, NULL);
  75
  76         perf_test_args.vm = vm;
  77
  78         /*
  79          * If there should be more memory in the guest test region than there
  80          * can be pages in the guest, it will definitely cause problems.
  81          */
  82         TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm),
  83                     "Requested more guest memory than address space allows.\n"
  84                     "    guest pages: %" PRIx64 " max gfn: %" PRIx64
  85                     " vcpus: %d wss: %" PRIx64 "]\n",
  86                     guest_num_pages, vm_get_max_gfn(vm), vcpus,
  87                     vcpu_memory_bytes);
  88
  89         guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
  90                               perf_test_args.guest_page_size;
  91         guest_test_phys_mem &= ~(perf_test_args.host_page_size - 1);
  92 #ifdef __s390x__
  93         /* Align to 1M (segment size) */
  94         guest_test_phys_mem &= ~((1 << 20) - 1);
  95 #endif
  96         pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
  97
  98         /* Add an extra memory slot for testing */
  99         vm_userspace_mem_region_add(vm, backing_src, guest_test_phys_mem,
 100                                     PERF_TEST_MEM_SLOT_INDEX,
 101                                     guest_num_pages, 0);
 102
 103         /* Do mapping for the demand paging memory slot */
 104         virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
 105
 106         ucall_init(vm, NULL);
 107
 108         return vm;
 109 }
 110
 111 void perf_test_destroy_vm(struct kvm_vm *vm)
 112 {
 113         ucall_uninit(vm);
 114         kvm_vm_free(vm);
 115 }
 116
 117 void perf_test_setup_vcpus(struct kvm_vm *vm, int vcpus,
 118                            uint64_t vcpu_memory_bytes,
 119                            bool partition_vcpu_memory_access)
 120 {
 121         vm_paddr_t vcpu_gpa;
 122         struct perf_test_vcpu_args *vcpu_args;
 123         int vcpu_id;
 124
 125         for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
 126                 vcpu_args = &perf_test_args.vcpu_args[vcpu_id];
 127
 128                 vcpu_args->vcpu_id = vcpu_id;
 129                 if (partition_vcpu_memory_access) {
 130                         vcpu_args->gva = guest_test_virt_mem +
 131                                          (vcpu_id * vcpu_memory_bytes);
 132                         vcpu_args->pages = vcpu_memory_bytes /
 133                                            perf_test_args.guest_page_size;
 134                         vcpu_gpa = guest_test_phys_mem +
 135                                    (vcpu_id * vcpu_memory_bytes);
 136                 } else {
 137                         vcpu_args->gva = guest_test_virt_mem;
 138                         vcpu_args->pages = (vcpus * vcpu_memory_bytes) /
 139                                            perf_test_args.guest_page_size;
 140                         vcpu_gpa = guest_test_phys_mem;
 141                 }
 142
 143                 pr_debug("Added VCPU %d with test mem gpa [%lx, %lx)\n",
 144                          vcpu_id, vcpu_gpa, vcpu_gpa +
 145                          (vcpu_args->pages * perf_test_args.guest_page_size));
 146         }
 147 }