1 /* 2 * ARM mach-virt emulation 3 * 4 * Copyright (c) 2013 Linaro Limited 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2 or later, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program. If not, see <http://www.gnu.org/licenses/>. 17 * 18 * Emulate a virtual board which works by passing Linux all the information 19 * it needs about what devices are present via the device tree. 20 * There are some restrictions about what we can do here: 21 * + we can only present devices whose Linux drivers will work based 22 * purely on the device tree with no platform data at all 23 * + we want to present a very stripped-down minimalist platform, 24 * both because this reduces the security attack surface from the guest 25 * and also because it reduces our exposure to being broken when 26 * the kernel updates its device tree bindings and requires further 27 * information in a device binding that we aren't providing. 28 * This is essentially the same approach kvmtool uses. 29 */ 30 31 #include "hw/sysbus.h" 32 #include "hw/arm/arm.h" 33 #include "hw/arm/primecell.h" 34 #include "hw/devices.h" 35 #include "net/net.h" 36 #include "sysemu/device_tree.h" 37 #include "sysemu/sysemu.h" 38 #include "sysemu/kvm.h" 39 #include "hw/boards.h" 40 #include "exec/address-spaces.h" 41 #include "qemu/bitops.h" 42 #include "qemu/error-report.h" 43 44 #define NUM_VIRTIO_TRANSPORTS 32 45 46 /* Number of external interrupt lines to configure the GIC with */ 47 #define NUM_IRQS 128 48 49 #define GIC_FDT_IRQ_TYPE_SPI 0 50 #define GIC_FDT_IRQ_TYPE_PPI 1 51 52 #define GIC_FDT_IRQ_FLAGS_EDGE_LO_HI 1 53 #define GIC_FDT_IRQ_FLAGS_EDGE_HI_LO 2 54 #define GIC_FDT_IRQ_FLAGS_LEVEL_HI 4 55 #define GIC_FDT_IRQ_FLAGS_LEVEL_LO 8 56 57 #define GIC_FDT_IRQ_PPI_CPU_START 8 58 #define GIC_FDT_IRQ_PPI_CPU_WIDTH 8 59 60 enum { 61 VIRT_FLASH, 62 VIRT_MEM, 63 VIRT_CPUPERIPHS, 64 VIRT_GIC_DIST, 65 VIRT_GIC_CPU, 66 VIRT_UART, 67 VIRT_MMIO, 68 }; 69 70 typedef struct MemMapEntry { 71 hwaddr base; 72 hwaddr size; 73 } MemMapEntry; 74 75 typedef struct VirtBoardInfo { 76 struct arm_boot_info bootinfo; 77 const char *cpu_model; 78 const char *qdevname; 79 const char *gic_compatible; 80 const MemMapEntry *memmap; 81 const int *irqmap; 82 int smp_cpus; 83 void *fdt; 84 int fdt_size; 85 uint32_t clock_phandle; 86 } VirtBoardInfo; 87 88 /* Addresses and sizes of our components. 89 * 0..128MB is space for a flash device so we can run bootrom code such as UEFI. 90 * 128MB..256MB is used for miscellaneous device I/O. 91 * 256MB..1GB is reserved for possible future PCI support (ie where the 92 * PCI memory window will go if we add a PCI host controller). 93 * 1GB and up is RAM (which may happily spill over into the 94 * high memory region beyond 4GB). 95 * This represents a compromise between how much RAM can be given to 96 * a 32 bit VM and leaving space for expansion and in particular for PCI. 97 */ 98 static const MemMapEntry a15memmap[] = { 99 /* Space up to 0x8000000 is reserved for a boot ROM */ 100 [VIRT_FLASH] = { 0, 0x8000000 }, 101 [VIRT_CPUPERIPHS] = { 0x8000000, 0x8000 }, 102 /* GIC distributor and CPU interfaces sit inside the CPU peripheral space */ 103 [VIRT_GIC_DIST] = { 0x8001000, 0x1000 }, 104 [VIRT_GIC_CPU] = { 0x8002000, 0x1000 }, 105 [VIRT_UART] = { 0x9000000, 0x1000 }, 106 [VIRT_MMIO] = { 0xa000000, 0x200 }, 107 /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */ 108 /* 0x10000000 .. 0x40000000 reserved for PCI */ 109 [VIRT_MEM] = { 0x40000000, 30ULL * 1024 * 1024 * 1024 }, 110 }; 111 112 static const int a15irqmap[] = { 113 [VIRT_UART] = 1, 114 [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */ 115 }; 116 117 static VirtBoardInfo machines[] = { 118 { 119 .cpu_model = "cortex-a15", 120 .qdevname = "a15mpcore_priv", 121 .gic_compatible = "arm,cortex-a15-gic", 122 .memmap = a15memmap, 123 .irqmap = a15irqmap, 124 }, 125 { 126 .cpu_model = "host", 127 /* We use the A15 private peripheral model to get a V2 GIC */ 128 .qdevname = "a15mpcore_priv", 129 .gic_compatible = "arm,cortex-a15-gic", 130 .memmap = a15memmap, 131 .irqmap = a15irqmap, 132 }, 133 }; 134 135 static VirtBoardInfo *find_machine_info(const char *cpu) 136 { 137 int i; 138 139 for (i = 0; i < ARRAY_SIZE(machines); i++) { 140 if (strcmp(cpu, machines[i].cpu_model) == 0) { 141 return &machines[i]; 142 } 143 } 144 return NULL; 145 } 146 147 static void create_fdt(VirtBoardInfo *vbi) 148 { 149 void *fdt = create_device_tree(&vbi->fdt_size); 150 151 if (!fdt) { 152 error_report("create_device_tree() failed"); 153 exit(1); 154 } 155 156 vbi->fdt = fdt; 157 158 /* Header */ 159 qemu_fdt_setprop_string(fdt, "/", "compatible", "linux,dummy-virt"); 160 qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2); 161 qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2); 162 163 /* 164 * /chosen and /memory nodes must exist for load_dtb 165 * to fill in necessary properties later 166 */ 167 qemu_fdt_add_subnode(fdt, "/chosen"); 168 qemu_fdt_add_subnode(fdt, "/memory"); 169 qemu_fdt_setprop_string(fdt, "/memory", "device_type", "memory"); 170 171 /* Clock node, for the benefit of the UART. The kernel device tree 172 * binding documentation claims the PL011 node clock properties are 173 * optional but in practice if you omit them the kernel refuses to 174 * probe for the device. 175 */ 176 vbi->clock_phandle = qemu_fdt_alloc_phandle(fdt); 177 qemu_fdt_add_subnode(fdt, "/apb-pclk"); 178 qemu_fdt_setprop_string(fdt, "/apb-pclk", "compatible", "fixed-clock"); 179 qemu_fdt_setprop_cell(fdt, "/apb-pclk", "#clock-cells", 0x0); 180 qemu_fdt_setprop_cell(fdt, "/apb-pclk", "clock-frequency", 24000000); 181 qemu_fdt_setprop_string(fdt, "/apb-pclk", "clock-output-names", 182 "clk24mhz"); 183 qemu_fdt_setprop_cell(fdt, "/apb-pclk", "phandle", vbi->clock_phandle); 184 185 /* No PSCI for TCG yet */ 186 if (kvm_enabled()) { 187 qemu_fdt_add_subnode(fdt, "/psci"); 188 qemu_fdt_setprop_string(fdt, "/psci", "compatible", "arm,psci"); 189 qemu_fdt_setprop_string(fdt, "/psci", "method", "hvc"); 190 qemu_fdt_setprop_cell(fdt, "/psci", "cpu_suspend", 191 PSCI_FN_CPU_SUSPEND); 192 qemu_fdt_setprop_cell(fdt, "/psci", "cpu_off", PSCI_FN_CPU_OFF); 193 qemu_fdt_setprop_cell(fdt, "/psci", "cpu_on", PSCI_FN_CPU_ON); 194 qemu_fdt_setprop_cell(fdt, "/psci", "migrate", PSCI_FN_MIGRATE); 195 } 196 } 197 198 static void fdt_add_timer_nodes(const VirtBoardInfo *vbi) 199 { 200 /* Note that on A15 h/w these interrupts are level-triggered, 201 * but for the GIC implementation provided by both QEMU and KVM 202 * they are edge-triggered. 203 */ 204 uint32_t irqflags = GIC_FDT_IRQ_FLAGS_EDGE_LO_HI; 205 206 irqflags = deposit32(irqflags, GIC_FDT_IRQ_PPI_CPU_START, 207 GIC_FDT_IRQ_PPI_CPU_WIDTH, (1 << vbi->smp_cpus) - 1); 208 209 qemu_fdt_add_subnode(vbi->fdt, "/timer"); 210 qemu_fdt_setprop_string(vbi->fdt, "/timer", 211 "compatible", "arm,armv7-timer"); 212 qemu_fdt_setprop_cells(vbi->fdt, "/timer", "interrupts", 213 GIC_FDT_IRQ_TYPE_PPI, 13, irqflags, 214 GIC_FDT_IRQ_TYPE_PPI, 14, irqflags, 215 GIC_FDT_IRQ_TYPE_PPI, 11, irqflags, 216 GIC_FDT_IRQ_TYPE_PPI, 10, irqflags); 217 } 218 219 static void fdt_add_cpu_nodes(const VirtBoardInfo *vbi) 220 { 221 int cpu; 222 223 qemu_fdt_add_subnode(vbi->fdt, "/cpus"); 224 qemu_fdt_setprop_cell(vbi->fdt, "/cpus", "#address-cells", 0x1); 225 qemu_fdt_setprop_cell(vbi->fdt, "/cpus", "#size-cells", 0x0); 226 227 for (cpu = vbi->smp_cpus - 1; cpu >= 0; cpu--) { 228 char *nodename = g_strdup_printf("/cpus/cpu@%d", cpu); 229 ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(cpu)); 230 231 qemu_fdt_add_subnode(vbi->fdt, nodename); 232 qemu_fdt_setprop_string(vbi->fdt, nodename, "device_type", "cpu"); 233 qemu_fdt_setprop_string(vbi->fdt, nodename, "compatible", 234 armcpu->dtb_compatible); 235 236 if (vbi->smp_cpus > 1) { 237 qemu_fdt_setprop_string(vbi->fdt, nodename, 238 "enable-method", "psci"); 239 } 240 241 qemu_fdt_setprop_cell(vbi->fdt, nodename, "reg", cpu); 242 g_free(nodename); 243 } 244 } 245 246 static void fdt_add_gic_node(const VirtBoardInfo *vbi) 247 { 248 uint32_t gic_phandle; 249 250 gic_phandle = qemu_fdt_alloc_phandle(vbi->fdt); 251 qemu_fdt_setprop_cell(vbi->fdt, "/", "interrupt-parent", gic_phandle); 252 253 qemu_fdt_add_subnode(vbi->fdt, "/intc"); 254 qemu_fdt_setprop_string(vbi->fdt, "/intc", "compatible", 255 vbi->gic_compatible); 256 qemu_fdt_setprop_cell(vbi->fdt, "/intc", "#interrupt-cells", 3); 257 qemu_fdt_setprop(vbi->fdt, "/intc", "interrupt-controller", NULL, 0); 258 qemu_fdt_setprop_sized_cells(vbi->fdt, "/intc", "reg", 259 2, vbi->memmap[VIRT_GIC_DIST].base, 260 2, vbi->memmap[VIRT_GIC_DIST].size, 261 2, vbi->memmap[VIRT_GIC_CPU].base, 262 2, vbi->memmap[VIRT_GIC_CPU].size); 263 qemu_fdt_setprop_cell(vbi->fdt, "/intc", "phandle", gic_phandle); 264 } 265 266 static void create_uart(const VirtBoardInfo *vbi, qemu_irq *pic) 267 { 268 char *nodename; 269 hwaddr base = vbi->memmap[VIRT_UART].base; 270 hwaddr size = vbi->memmap[VIRT_UART].size; 271 int irq = vbi->irqmap[VIRT_UART]; 272 const char compat[] = "arm,pl011\0arm,primecell"; 273 const char clocknames[] = "uartclk\0apb_pclk"; 274 275 sysbus_create_simple("pl011", base, pic[irq]); 276 277 nodename = g_strdup_printf("/pl011@%" PRIx64, base); 278 qemu_fdt_add_subnode(vbi->fdt, nodename); 279 /* Note that we can't use setprop_string because of the embedded NUL */ 280 qemu_fdt_setprop(vbi->fdt, nodename, "compatible", 281 compat, sizeof(compat)); 282 qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg", 283 2, base, 2, size); 284 qemu_fdt_setprop_cells(vbi->fdt, nodename, "interrupts", 285 GIC_FDT_IRQ_TYPE_SPI, irq, 286 GIC_FDT_IRQ_FLAGS_EDGE_LO_HI); 287 qemu_fdt_setprop_cells(vbi->fdt, nodename, "clocks", 288 vbi->clock_phandle, vbi->clock_phandle); 289 qemu_fdt_setprop(vbi->fdt, nodename, "clock-names", 290 clocknames, sizeof(clocknames)); 291 g_free(nodename); 292 } 293 294 static void create_virtio_devices(const VirtBoardInfo *vbi, qemu_irq *pic) 295 { 296 int i; 297 hwaddr size = vbi->memmap[VIRT_MMIO].size; 298 299 /* Note that we have to create the transports in forwards order 300 * so that command line devices are inserted lowest address first, 301 * and then add dtb nodes in reverse order so that they appear in 302 * the finished device tree lowest address first. 303 */ 304 for (i = 0; i < NUM_VIRTIO_TRANSPORTS; i++) { 305 int irq = vbi->irqmap[VIRT_MMIO] + i; 306 hwaddr base = vbi->memmap[VIRT_MMIO].base + i * size; 307 308 sysbus_create_simple("virtio-mmio", base, pic[irq]); 309 } 310 311 for (i = NUM_VIRTIO_TRANSPORTS - 1; i >= 0; i--) { 312 char *nodename; 313 int irq = vbi->irqmap[VIRT_MMIO] + i; 314 hwaddr base = vbi->memmap[VIRT_MMIO].base + i * size; 315 316 nodename = g_strdup_printf("/virtio_mmio@%" PRIx64, base); 317 qemu_fdt_add_subnode(vbi->fdt, nodename); 318 qemu_fdt_setprop_string(vbi->fdt, nodename, 319 "compatible", "virtio,mmio"); 320 qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg", 321 2, base, 2, size); 322 qemu_fdt_setprop_cells(vbi->fdt, nodename, "interrupts", 323 GIC_FDT_IRQ_TYPE_SPI, irq, 324 GIC_FDT_IRQ_FLAGS_EDGE_LO_HI); 325 g_free(nodename); 326 } 327 } 328 329 static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size) 330 { 331 const VirtBoardInfo *board = (const VirtBoardInfo *)binfo; 332 333 *fdt_size = board->fdt_size; 334 return board->fdt; 335 } 336 337 static void machvirt_init(QEMUMachineInitArgs *args) 338 { 339 qemu_irq pic[NUM_IRQS]; 340 MemoryRegion *sysmem = get_system_memory(); 341 int n; 342 MemoryRegion *ram = g_new(MemoryRegion, 1); 343 DeviceState *dev; 344 SysBusDevice *busdev; 345 const char *cpu_model = args->cpu_model; 346 VirtBoardInfo *vbi; 347 348 if (!cpu_model) { 349 cpu_model = "cortex-a15"; 350 } 351 352 vbi = find_machine_info(cpu_model); 353 354 if (!vbi) { 355 error_report("mach-virt: CPU %s not supported", cpu_model); 356 exit(1); 357 } 358 359 vbi->smp_cpus = smp_cpus; 360 361 /* 362 * Only supported method of starting secondary CPUs is PSCI and 363 * PSCI is not yet supported with TCG, so limit smp_cpus to 1 364 * if we're not using KVM. 365 */ 366 if (!kvm_enabled() && smp_cpus > 1) { 367 error_report("mach-virt: must enable KVM to use multiple CPUs"); 368 exit(1); 369 } 370 371 if (args->ram_size > vbi->memmap[VIRT_MEM].size) { 372 error_report("mach-virt: cannot model more than 30GB RAM"); 373 exit(1); 374 } 375 376 create_fdt(vbi); 377 fdt_add_timer_nodes(vbi); 378 379 for (n = 0; n < smp_cpus; n++) { 380 ObjectClass *oc = cpu_class_by_name(TYPE_ARM_CPU, cpu_model); 381 Object *cpuobj; 382 383 if (!oc) { 384 fprintf(stderr, "Unable to find CPU definition\n"); 385 exit(1); 386 } 387 cpuobj = object_new(object_class_get_name(oc)); 388 389 /* Secondary CPUs start in PSCI powered-down state */ 390 if (n > 0) { 391 object_property_set_bool(cpuobj, true, "start-powered-off", NULL); 392 } 393 394 if (object_property_find(cpuobj, "reset-cbar", NULL)) { 395 object_property_set_int(cpuobj, vbi->memmap[VIRT_CPUPERIPHS].base, 396 "reset-cbar", &error_abort); 397 } 398 399 object_property_set_bool(cpuobj, true, "realized", NULL); 400 } 401 fdt_add_cpu_nodes(vbi); 402 403 memory_region_init_ram(ram, NULL, "mach-virt.ram", args->ram_size); 404 vmstate_register_ram_global(ram); 405 memory_region_add_subregion(sysmem, vbi->memmap[VIRT_MEM].base, ram); 406 407 dev = qdev_create(NULL, vbi->qdevname); 408 qdev_prop_set_uint32(dev, "num-cpu", smp_cpus); 409 /* Note that the num-irq property counts both internal and external 410 * interrupts; there are always 32 of the former (mandated by GIC spec). 411 */ 412 qdev_prop_set_uint32(dev, "num-irq", NUM_IRQS + 32); 413 qdev_init_nofail(dev); 414 busdev = SYS_BUS_DEVICE(dev); 415 sysbus_mmio_map(busdev, 0, vbi->memmap[VIRT_CPUPERIPHS].base); 416 fdt_add_gic_node(vbi); 417 for (n = 0; n < smp_cpus; n++) { 418 DeviceState *cpudev = DEVICE(qemu_get_cpu(n)); 419 420 sysbus_connect_irq(busdev, n, qdev_get_gpio_in(cpudev, ARM_CPU_IRQ)); 421 } 422 423 for (n = 0; n < NUM_IRQS; n++) { 424 pic[n] = qdev_get_gpio_in(dev, n); 425 } 426 427 create_uart(vbi, pic); 428 429 /* Create mmio transports, so the user can create virtio backends 430 * (which will be automatically plugged in to the transports). If 431 * no backend is created the transport will just sit harmlessly idle. 432 */ 433 create_virtio_devices(vbi, pic); 434 435 vbi->bootinfo.ram_size = args->ram_size; 436 vbi->bootinfo.kernel_filename = args->kernel_filename; 437 vbi->bootinfo.kernel_cmdline = args->kernel_cmdline; 438 vbi->bootinfo.initrd_filename = args->initrd_filename; 439 vbi->bootinfo.nb_cpus = smp_cpus; 440 vbi->bootinfo.board_id = -1; 441 vbi->bootinfo.loader_start = vbi->memmap[VIRT_MEM].base; 442 vbi->bootinfo.get_dtb = machvirt_dtb; 443 arm_load_kernel(ARM_CPU(first_cpu), &vbi->bootinfo); 444 } 445 446 static QEMUMachine machvirt_a15_machine = { 447 .name = "virt", 448 .desc = "ARM Virtual Machine", 449 .init = machvirt_init, 450 .max_cpus = 4, 451 }; 452 453 static void machvirt_machine_init(void) 454 { 455 qemu_register_machine(&machvirt_a15_machine); 456 } 457 458 machine_init(machvirt_machine_init); 459