hw/arm/virt.c

   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 MemMapEntry *memmap;
  79     const int *irqmap;
  80     int smp_cpus;
  81     void *fdt;
  82     int fdt_size;
  83     uint32_t clock_phandle;
  84 } VirtBoardInfo;
  85
  86 /* Addresses and sizes of our components.
  87  * 0..128MB is space for a flash device so we can run bootrom code such as UEFI.
  88  * 128MB..256MB is used for miscellaneous device I/O.
  89  * 256MB..1GB is reserved for possible future PCI support (ie where the
  90  * PCI memory window will go if we add a PCI host controller).
  91  * 1GB and up is RAM (which may happily spill over into the
  92  * high memory region beyond 4GB).
  93  * This represents a compromise between how much RAM can be given to
  94  * a 32 bit VM and leaving space for expansion and in particular for PCI.
  95  */
  96 static const MemMapEntry a15memmap[] = {
  97     /* Space up to 0x8000000 is reserved for a boot ROM */
  98     [VIRT_FLASH] = { 0, 0x8000000 },
  99     [VIRT_CPUPERIPHS] = { 0x8000000, 0x20000 },
 100     /* GIC distributor and CPU interfaces sit inside the CPU peripheral space */
 101     [VIRT_GIC_DIST] = { 0x8000000, 0x10000 },
 102     [VIRT_GIC_CPU] = { 0x8010000, 0x10000 },
 103     [VIRT_UART] = { 0x9000000, 0x1000 },
 104     [VIRT_MMIO] = { 0xa000000, 0x200 },
 105     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
 106     /* 0x10000000 .. 0x40000000 reserved for PCI */
 107     [VIRT_MEM] = { 0x40000000, 30ULL * 1024 * 1024 * 1024 },
 108 };
 109
 110 static const int a15irqmap[] = {
 111     [VIRT_UART] = 1,
 112     [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */
 113 };
 114
 115 static VirtBoardInfo machines[] = {
 116     {
 117         .cpu_model = "cortex-a15",
 118         .memmap = a15memmap,
 119         .irqmap = a15irqmap,
 120     },
 121     {
 122         .cpu_model = "cortex-a57",
 123         .memmap = a15memmap,
 124         .irqmap = a15irqmap,
 125     },
 126     {
 127         .cpu_model = "host",
 128         .memmap = a15memmap,
 129         .irqmap = a15irqmap,
 130     },
 131 };
 132
 133 static VirtBoardInfo *find_machine_info(const char *cpu)
 134 {
 135     int i;
 136
 137     for (i = 0; i < ARRAY_SIZE(machines); i++) {
 138         if (strcmp(cpu, machines[i].cpu_model) == 0) {
 139             return &machines[i];
 140         }
 141     }
 142     return NULL;
 143 }
 144
 145 static void create_fdt(VirtBoardInfo *vbi)
 146 {
 147     void *fdt = create_device_tree(&vbi->fdt_size);
 148
 149     if (!fdt) {
 150         error_report("create_device_tree() failed");
 151         exit(1);
 152     }
 153
 154     vbi->fdt = fdt;
 155
 156     /* Header */
 157     qemu_fdt_setprop_string(fdt, "/", "compatible", "linux,dummy-virt");
 158     qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2);
 159     qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2);
 160
 161     /*
 162      * /chosen and /memory nodes must exist for load_dtb
 163      * to fill in necessary properties later
 164      */
 165     qemu_fdt_add_subnode(fdt, "/chosen");
 166     qemu_fdt_add_subnode(fdt, "/memory");
 167     qemu_fdt_setprop_string(fdt, "/memory", "device_type", "memory");
 168
 169     /* Clock node, for the benefit of the UART. The kernel device tree
 170      * binding documentation claims the PL011 node clock properties are
 171      * optional but in practice if you omit them the kernel refuses to
 172      * probe for the device.
 173      */
 174     vbi->clock_phandle = qemu_fdt_alloc_phandle(fdt);
 175     qemu_fdt_add_subnode(fdt, "/apb-pclk");
 176     qemu_fdt_setprop_string(fdt, "/apb-pclk", "compatible", "fixed-clock");
 177     qemu_fdt_setprop_cell(fdt, "/apb-pclk", "#clock-cells", 0x0);
 178     qemu_fdt_setprop_cell(fdt, "/apb-pclk", "clock-frequency", 24000000);
 179     qemu_fdt_setprop_string(fdt, "/apb-pclk", "clock-output-names",
 180                                 "clk24mhz");
 181     qemu_fdt_setprop_cell(fdt, "/apb-pclk", "phandle", vbi->clock_phandle);
 182
 183     /* No PSCI for TCG yet */
 184     if (kvm_enabled()) {
 185         qemu_fdt_add_subnode(fdt, "/psci");
 186         qemu_fdt_setprop_string(fdt, "/psci", "compatible", "arm,psci");
 187         qemu_fdt_setprop_string(fdt, "/psci", "method", "hvc");
 188         qemu_fdt_setprop_cell(fdt, "/psci", "cpu_suspend",
 189                                   PSCI_FN_CPU_SUSPEND);
 190         qemu_fdt_setprop_cell(fdt, "/psci", "cpu_off", PSCI_FN_CPU_OFF);
 191         qemu_fdt_setprop_cell(fdt, "/psci", "cpu_on", PSCI_FN_CPU_ON);
 192         qemu_fdt_setprop_cell(fdt, "/psci", "migrate", PSCI_FN_MIGRATE);
 193     }
 194 }
 195
 196 static void fdt_add_timer_nodes(const VirtBoardInfo *vbi)
 197 {
 198     /* Note that on A15 h/w these interrupts are level-triggered,
 199      * but for the GIC implementation provided by both QEMU and KVM
 200      * they are edge-triggered.
 201      */
 202     uint32_t irqflags = GIC_FDT_IRQ_FLAGS_EDGE_LO_HI;
 203
 204     irqflags = deposit32(irqflags, GIC_FDT_IRQ_PPI_CPU_START,
 205                          GIC_FDT_IRQ_PPI_CPU_WIDTH, (1 << vbi->smp_cpus) - 1);
 206
 207     qemu_fdt_add_subnode(vbi->fdt, "/timer");
 208     qemu_fdt_setprop_string(vbi->fdt, "/timer",
 209                                 "compatible", "arm,armv7-timer");
 210     qemu_fdt_setprop_cells(vbi->fdt, "/timer", "interrupts",
 211                                GIC_FDT_IRQ_TYPE_PPI, 13, irqflags,
 212                                GIC_FDT_IRQ_TYPE_PPI, 14, irqflags,
 213                                GIC_FDT_IRQ_TYPE_PPI, 11, irqflags,
 214                                GIC_FDT_IRQ_TYPE_PPI, 10, irqflags);
 215 }
 216
 217 static void fdt_add_cpu_nodes(const VirtBoardInfo *vbi)
 218 {
 219     int cpu;
 220
 221     qemu_fdt_add_subnode(vbi->fdt, "/cpus");
 222     qemu_fdt_setprop_cell(vbi->fdt, "/cpus", "#address-cells", 0x1);
 223     qemu_fdt_setprop_cell(vbi->fdt, "/cpus", "#size-cells", 0x0);
 224
 225     for (cpu = vbi->smp_cpus - 1; cpu >= 0; cpu--) {
 226         char *nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
 227         ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(cpu));
 228
 229         qemu_fdt_add_subnode(vbi->fdt, nodename);
 230         qemu_fdt_setprop_string(vbi->fdt, nodename, "device_type", "cpu");
 231         qemu_fdt_setprop_string(vbi->fdt, nodename, "compatible",
 232                                     armcpu->dtb_compatible);
 233
 234         if (vbi->smp_cpus > 1) {
 235             qemu_fdt_setprop_string(vbi->fdt, nodename,
 236                                         "enable-method", "psci");
 237         }
 238
 239         qemu_fdt_setprop_cell(vbi->fdt, nodename, "reg", cpu);
 240         g_free(nodename);
 241     }
 242 }
 243
 244 static void fdt_add_gic_node(const VirtBoardInfo *vbi)
 245 {
 246     uint32_t gic_phandle;
 247
 248     gic_phandle = qemu_fdt_alloc_phandle(vbi->fdt);
 249     qemu_fdt_setprop_cell(vbi->fdt, "/", "interrupt-parent", gic_phandle);
 250
 251     qemu_fdt_add_subnode(vbi->fdt, "/intc");
 252     /* 'cortex-a15-gic' means 'GIC v2' */
 253     qemu_fdt_setprop_string(vbi->fdt, "/intc", "compatible",
 254                             "arm,cortex-a15-gic");
 255     qemu_fdt_setprop_cell(vbi->fdt, "/intc", "#interrupt-cells", 3);
 256     qemu_fdt_setprop(vbi->fdt, "/intc", "interrupt-controller", NULL, 0);
 257     qemu_fdt_setprop_sized_cells(vbi->fdt, "/intc", "reg",
 258                                      2, vbi->memmap[VIRT_GIC_DIST].base,
 259                                      2, vbi->memmap[VIRT_GIC_DIST].size,
 260                                      2, vbi->memmap[VIRT_GIC_CPU].base,
 261                                      2, vbi->memmap[VIRT_GIC_CPU].size);
 262     qemu_fdt_setprop_cell(vbi->fdt, "/intc", "phandle", gic_phandle);
 263 }
 264
 265 static void create_gic(const VirtBoardInfo *vbi, qemu_irq *pic)
 266 {
 267     /* We create a standalone GIC v2 */
 268     DeviceState *gicdev;
 269     SysBusDevice *gicbusdev;
 270     const char *gictype = "arm_gic";
 271     int i;
 272
 273     if (kvm_irqchip_in_kernel()) {
 274         gictype = "kvm-arm-gic";
 275     }
 276
 277     gicdev = qdev_create(NULL, gictype);
 278     qdev_prop_set_uint32(gicdev, "revision", 2);
 279     qdev_prop_set_uint32(gicdev, "num-cpu", smp_cpus);
 280     /* Note that the num-irq property counts both internal and external
 281      * interrupts; there are always 32 of the former (mandated by GIC spec).
 282      */
 283     qdev_prop_set_uint32(gicdev, "num-irq", NUM_IRQS + 32);
 284     qdev_init_nofail(gicdev);
 285     gicbusdev = SYS_BUS_DEVICE(gicdev);
 286     sysbus_mmio_map(gicbusdev, 0, vbi->memmap[VIRT_GIC_DIST].base);
 287     sysbus_mmio_map(gicbusdev, 1, vbi->memmap[VIRT_GIC_CPU].base);
 288
 289     /* Wire the outputs from each CPU's generic timer to the
 290      * appropriate GIC PPI inputs, and the GIC's IRQ output to
 291      * the CPU's IRQ input.
 292      */
 293     for (i = 0; i < smp_cpus; i++) {
 294         DeviceState *cpudev = DEVICE(qemu_get_cpu(i));
 295         int ppibase = NUM_IRQS + i * 32;
 296         /* physical timer; we wire it up to the non-secure timer's ID,
 297          * since a real A15 always has TrustZone but QEMU doesn't.
 298          */
 299         qdev_connect_gpio_out(cpudev, 0,
 300                               qdev_get_gpio_in(gicdev, ppibase + 30));
 301         /* virtual timer */
 302         qdev_connect_gpio_out(cpudev, 1,
 303                               qdev_get_gpio_in(gicdev, ppibase + 27));
 304
 305         sysbus_connect_irq(gicbusdev, i, qdev_get_gpio_in(cpudev, ARM_CPU_IRQ));
 306     }
 307
 308     for (i = 0; i < NUM_IRQS; i++) {
 309         pic[i] = qdev_get_gpio_in(gicdev, i);
 310     }
 311
 312     fdt_add_gic_node(vbi);
 313 }
 314
 315 static void create_uart(const VirtBoardInfo *vbi, qemu_irq *pic)
 316 {
 317     char *nodename;
 318     hwaddr base = vbi->memmap[VIRT_UART].base;
 319     hwaddr size = vbi->memmap[VIRT_UART].size;
 320     int irq = vbi->irqmap[VIRT_UART];
 321     const char compat[] = "arm,pl011\0arm,primecell";
 322     const char clocknames[] = "uartclk\0apb_pclk";
 323
 324     sysbus_create_simple("pl011", base, pic[irq]);
 325
 326     nodename = g_strdup_printf("/pl011@%" PRIx64, base);
 327     qemu_fdt_add_subnode(vbi->fdt, nodename);
 328     /* Note that we can't use setprop_string because of the embedded NUL */
 329     qemu_fdt_setprop(vbi->fdt, nodename, "compatible",
 330                          compat, sizeof(compat));
 331     qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg",
 332                                      2, base, 2, size);
 333     qemu_fdt_setprop_cells(vbi->fdt, nodename, "interrupts",
 334                                GIC_FDT_IRQ_TYPE_SPI, irq,
 335                                GIC_FDT_IRQ_FLAGS_EDGE_LO_HI);
 336     qemu_fdt_setprop_cells(vbi->fdt, nodename, "clocks",
 337                                vbi->clock_phandle, vbi->clock_phandle);
 338     qemu_fdt_setprop(vbi->fdt, nodename, "clock-names",
 339                          clocknames, sizeof(clocknames));
 340     g_free(nodename);
 341 }
 342
 343 static void create_virtio_devices(const VirtBoardInfo *vbi, qemu_irq *pic)
 344 {
 345     int i;
 346     hwaddr size = vbi->memmap[VIRT_MMIO].size;
 347
 348     /* Note that we have to create the transports in forwards order
 349      * so that command line devices are inserted lowest address first,
 350      * and then add dtb nodes in reverse order so that they appear in
 351      * the finished device tree lowest address first.
 352      */
 353     for (i = 0; i < NUM_VIRTIO_TRANSPORTS; i++) {
 354         int irq = vbi->irqmap[VIRT_MMIO] + i;
 355         hwaddr base = vbi->memmap[VIRT_MMIO].base + i * size;
 356
 357         sysbus_create_simple("virtio-mmio", base, pic[irq]);
 358     }
 359
 360     for (i = NUM_VIRTIO_TRANSPORTS - 1; i >= 0; i--) {
 361         char *nodename;
 362         int irq = vbi->irqmap[VIRT_MMIO] + i;
 363         hwaddr base = vbi->memmap[VIRT_MMIO].base + i * size;
 364
 365         nodename = g_strdup_printf("/virtio_mmio@%" PRIx64, base);
 366         qemu_fdt_add_subnode(vbi->fdt, nodename);
 367         qemu_fdt_setprop_string(vbi->fdt, nodename,
 368                                 "compatible", "virtio,mmio");
 369         qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg",
 370                                      2, base, 2, size);
 371         qemu_fdt_setprop_cells(vbi->fdt, nodename, "interrupts",
 372                                GIC_FDT_IRQ_TYPE_SPI, irq,
 373                                GIC_FDT_IRQ_FLAGS_EDGE_LO_HI);
 374         g_free(nodename);
 375     }
 376 }
 377
 378 static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)
 379 {
 380     const VirtBoardInfo *board = (const VirtBoardInfo *)binfo;
 381
 382     *fdt_size = board->fdt_size;
 383     return board->fdt;
 384 }
 385
 386 static void machvirt_init(QEMUMachineInitArgs *args)
 387 {
 388     qemu_irq pic[NUM_IRQS];
 389     MemoryRegion *sysmem = get_system_memory();
 390     int n;
 391     MemoryRegion *ram = g_new(MemoryRegion, 1);
 392     const char *cpu_model = args->cpu_model;
 393     VirtBoardInfo *vbi;
 394
 395     if (!cpu_model) {
 396         cpu_model = "cortex-a15";
 397     }
 398
 399     vbi = find_machine_info(cpu_model);
 400
 401     if (!vbi) {
 402         error_report("mach-virt: CPU %s not supported", cpu_model);
 403         exit(1);
 404     }
 405
 406     vbi->smp_cpus = smp_cpus;
 407
 408     /*
 409      * Only supported method of starting secondary CPUs is PSCI and
 410      * PSCI is not yet supported with TCG, so limit smp_cpus to 1
 411      * if we're not using KVM.
 412      */
 413     if (!kvm_enabled() && smp_cpus > 1) {
 414         error_report("mach-virt: must enable KVM to use multiple CPUs");
 415         exit(1);
 416     }
 417
 418     if (args->ram_size > vbi->memmap[VIRT_MEM].size) {
 419         error_report("mach-virt: cannot model more than 30GB RAM");
 420         exit(1);
 421     }
 422
 423     create_fdt(vbi);
 424     fdt_add_timer_nodes(vbi);
 425
 426     for (n = 0; n < smp_cpus; n++) {
 427         ObjectClass *oc = cpu_class_by_name(TYPE_ARM_CPU, cpu_model);
 428         Object *cpuobj;
 429
 430         if (!oc) {
 431             fprintf(stderr, "Unable to find CPU definition\n");
 432             exit(1);
 433         }
 434         cpuobj = object_new(object_class_get_name(oc));
 435
 436         /* Secondary CPUs start in PSCI powered-down state */
 437         if (n > 0) {
 438             object_property_set_bool(cpuobj, true, "start-powered-off", NULL);
 439         }
 440
 441         if (object_property_find(cpuobj, "reset-cbar", NULL)) {
 442             object_property_set_int(cpuobj, vbi->memmap[VIRT_CPUPERIPHS].base,
 443                                     "reset-cbar", &error_abort);
 444         }
 445
 446         object_property_set_bool(cpuobj, true, "realized", NULL);
 447     }
 448     fdt_add_cpu_nodes(vbi);
 449
 450     memory_region_init_ram(ram, NULL, "mach-virt.ram", args->ram_size);
 451     vmstate_register_ram_global(ram);
 452     memory_region_add_subregion(sysmem, vbi->memmap[VIRT_MEM].base, ram);
 453
 454     create_gic(vbi, pic);
 455
 456     create_uart(vbi, pic);
 457
 458     /* Create mmio transports, so the user can create virtio backends
 459      * (which will be automatically plugged in to the transports). If
 460      * no backend is created the transport will just sit harmlessly idle.
 461      */
 462     create_virtio_devices(vbi, pic);
 463
 464     vbi->bootinfo.ram_size = args->ram_size;
 465     vbi->bootinfo.kernel_filename = args->kernel_filename;
 466     vbi->bootinfo.kernel_cmdline = args->kernel_cmdline;
 467     vbi->bootinfo.initrd_filename = args->initrd_filename;
 468     vbi->bootinfo.nb_cpus = smp_cpus;
 469     vbi->bootinfo.board_id = -1;
 470     vbi->bootinfo.loader_start = vbi->memmap[VIRT_MEM].base;
 471     vbi->bootinfo.get_dtb = machvirt_dtb;
 472     arm_load_kernel(ARM_CPU(first_cpu), &vbi->bootinfo);
 473 }
 474
 475 static QEMUMachine machvirt_a15_machine = {
 476     .name = "virt",
 477     .desc = "ARM Virtual Machine",
 478     .init = machvirt_init,
 479     .max_cpus = 4,
 480 };
 481
 482 static void machvirt_machine_init(void)
 483 {
 484     qemu_register_machine(&machvirt_a15_machine);
 485 }
 486
 487 machine_init(machvirt_machine_init);