hw/char/spapr_vty.c

   1 #include "qemu/osdep.h"
   2 #include "qemu/error-report.h"
   3 #include "qemu/module.h"
   4 #include "qapi/error.h"
   5 #include "cpu.h"
   6 #include "hw/qdev.h"
   7 #include "chardev/char-fe.h"
   8 #include "hw/irq.h"
   9 #include "hw/ppc/spapr.h"
  10 #include "hw/ppc/spapr_vio.h"
  11
  12 #define VTERM_BUFSIZE   16
  13
  14 typedef struct SpaprVioVty {
  15     SpaprVioDevice sdev;
  16     CharBackend chardev;
  17     uint32_t in, out;
  18     uint8_t buf[VTERM_BUFSIZE];
  19 } SpaprVioVty;
  20
  21 #define TYPE_VIO_SPAPR_VTY_DEVICE "spapr-vty"
  22 #define VIO_SPAPR_VTY_DEVICE(obj) \
  23      OBJECT_CHECK(SpaprVioVty, (obj), TYPE_VIO_SPAPR_VTY_DEVICE)
  24
  25 static int vty_can_receive(void *opaque)
  26 {
  27     SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(opaque);
  28
  29     return VTERM_BUFSIZE - (dev->in - dev->out);
  30 }
  31
  32 static void vty_receive(void *opaque, const uint8_t *buf, int size)
  33 {
  34     SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(opaque);
  35     int i;
  36
  37     if ((dev->in == dev->out) && size) {
  38         /* toggle line to simulate edge interrupt */
  39         qemu_irq_pulse(spapr_vio_qirq(&dev->sdev));
  40     }
  41     for (i = 0; i < size; i++) {
  42         if (dev->in - dev->out >= VTERM_BUFSIZE) {
  43             static bool reported;
  44             if (!reported) {
  45                 error_report("VTY input buffer exhausted - characters dropped."
  46                              " (input size = %i)", size);
  47                 reported = true;
  48             }
  49             break;
  50         }
  51         dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
  52     }
  53 }
  54
  55 static int vty_getchars(SpaprVioDevice *sdev, uint8_t *buf, int max)
  56 {
  57     SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(sdev);
  58     int n = 0;
  59
  60     while ((n < max) && (dev->out != dev->in)) {
  61         buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
  62
  63         /* PowerVM's vty implementation has a bug where it inserts a
  64          * \0 after every \r going to the guest.  Existing guests have
  65          * a workaround for this which removes every \0 immediately
  66          * following a \r, so here we make ourselves bug-for-bug
  67          * compatible, so that the guest won't drop a real \0-after-\r
  68          * that happens to occur in a binary stream. */
  69         if (buf[n - 1] == '\r') {
  70             if (n < max) {
  71                 buf[n++] = '\0';
  72             } else {
  73                 /* No room for the extra \0, roll back and try again
  74                  * next time */
  75                 dev->out--;
  76                 n--;
  77                 break;
  78             }
  79         }
  80     }
  81
  82     qemu_chr_fe_accept_input(&dev->chardev);
  83
  84     return n;
  85 }
  86
  87 void vty_putchars(SpaprVioDevice *sdev, uint8_t *buf, int len)
  88 {
  89     SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(sdev);
  90
  91     /* XXX this blocks entire thread. Rewrite to use
  92      * qemu_chr_fe_write and background I/O callbacks */
  93     qemu_chr_fe_write_all(&dev->chardev, buf, len);
  94 }
  95
  96 static void spapr_vty_realize(SpaprVioDevice *sdev, Error **errp)
  97 {
  98     SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(sdev);
  99
 100     if (!qemu_chr_fe_backend_connected(&dev->chardev)) {
 101         error_setg(errp, "chardev property not set");
 102         return;
 103     }
 104
 105     qemu_chr_fe_set_handlers(&dev->chardev, vty_can_receive,
 106                              vty_receive, NULL, NULL, dev, NULL, true);
 107 }
 108
 109 /* Forward declaration */
 110 static target_ulong h_put_term_char(PowerPCCPU *cpu, SpaprMachineState *spapr,
 111                                     target_ulong opcode, target_ulong *args)
 112 {
 113     target_ulong reg = args[0];
 114     target_ulong len = args[1];
 115     target_ulong char0_7 = args[2];
 116     target_ulong char8_15 = args[3];
 117     SpaprVioDevice *sdev;
 118     uint8_t buf[16];
 119
 120     sdev = vty_lookup(spapr, reg);
 121     if (!sdev) {
 122         return H_PARAMETER;
 123     }
 124
 125     if (len > 16) {
 126         return H_PARAMETER;
 127     }
 128
 129     *((uint64_t *)buf) = cpu_to_be64(char0_7);
 130     *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);
 131
 132     vty_putchars(sdev, buf, len);
 133
 134     return H_SUCCESS;
 135 }
 136
 137 static target_ulong h_get_term_char(PowerPCCPU *cpu, SpaprMachineState *spapr,
 138                                     target_ulong opcode, target_ulong *args)
 139 {
 140     target_ulong reg = args[0];
 141     target_ulong *len = args + 0;
 142     target_ulong *char0_7 = args + 1;
 143     target_ulong *char8_15 = args + 2;
 144     SpaprVioDevice *sdev;
 145     uint8_t buf[16];
 146
 147     sdev = vty_lookup(spapr, reg);
 148     if (!sdev) {
 149         return H_PARAMETER;
 150     }
 151
 152     *len = vty_getchars(sdev, buf, sizeof(buf));
 153     if (*len < 16) {
 154         memset(buf + *len, 0, 16 - *len);
 155     }
 156
 157     *char0_7 = be64_to_cpu(*((uint64_t *)buf));
 158     *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));
 159
 160     return H_SUCCESS;
 161 }
 162
 163 void spapr_vty_create(SpaprVioBus *bus, Chardev *chardev)
 164 {
 165     DeviceState *dev;
 166
 167     dev = qdev_create(&bus->bus, "spapr-vty");
 168     qdev_prop_set_chr(dev, "chardev", chardev);
 169     qdev_init_nofail(dev);
 170 }
 171
 172 static Property spapr_vty_properties[] = {
 173     DEFINE_SPAPR_PROPERTIES(SpaprVioVty, sdev),
 174     DEFINE_PROP_CHR("chardev", SpaprVioVty, chardev),
 175     DEFINE_PROP_END_OF_LIST(),
 176 };
 177
 178 static const VMStateDescription vmstate_spapr_vty = {
 179     .name = "spapr_vty",
 180     .version_id = 1,
 181     .minimum_version_id = 1,
 182     .fields = (VMStateField[]) {
 183         VMSTATE_SPAPR_VIO(sdev, SpaprVioVty),
 184
 185         VMSTATE_UINT32(in, SpaprVioVty),
 186         VMSTATE_UINT32(out, SpaprVioVty),
 187         VMSTATE_BUFFER(buf, SpaprVioVty),
 188         VMSTATE_END_OF_LIST()
 189     },
 190 };
 191
 192 static void spapr_vty_class_init(ObjectClass *klass, void *data)
 193 {
 194     DeviceClass *dc = DEVICE_CLASS(klass);
 195     SpaprVioDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
 196
 197     k->realize = spapr_vty_realize;
 198     k->dt_name = "vty";
 199     k->dt_type = "serial";
 200     k->dt_compatible = "hvterm1";
 201     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 202     dc->props = spapr_vty_properties;
 203     dc->vmsd = &vmstate_spapr_vty;
 204 }
 205
 206 static const TypeInfo spapr_vty_info = {
 207     .name          = TYPE_VIO_SPAPR_VTY_DEVICE,
 208     .parent        = TYPE_VIO_SPAPR_DEVICE,
 209     .instance_size = sizeof(SpaprVioVty),
 210     .class_init    = spapr_vty_class_init,
 211 };
 212
 213 SpaprVioDevice *spapr_vty_get_default(SpaprVioBus *bus)
 214 {
 215     SpaprVioDevice *sdev, *selected;
 216     BusChild *kid;
 217
 218     /*
 219      * To avoid the console bouncing around we want one VTY to be
 220      * the "default". We haven't really got anything to go on, so
 221      * arbitrarily choose the one with the lowest reg value.
 222      */
 223
 224     selected = NULL;
 225     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 226         DeviceState *iter = kid->child;
 227
 228         /* Only look at VTY devices */
 229         if (!object_dynamic_cast(OBJECT(iter), TYPE_VIO_SPAPR_VTY_DEVICE)) {
 230             continue;
 231         }
 232
 233         sdev = VIO_SPAPR_DEVICE(iter);
 234
 235         /* First VTY we've found, so it is selected for now */
 236         if (!selected) {
 237             selected = sdev;
 238             continue;
 239         }
 240
 241         /* Choose VTY with lowest reg value */
 242         if (sdev->reg < selected->reg) {
 243             selected = sdev;
 244         }
 245     }
 246
 247     return selected;
 248 }
 249
 250 SpaprVioDevice *vty_lookup(SpaprMachineState *spapr, target_ulong reg)
 251 {
 252     SpaprVioDevice *sdev;
 253
 254     sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 255     if (!sdev && reg == 0) {
 256         /* Hack for kernel early debug, which always specifies reg==0.
 257          * We search all VIO devices, and grab the vty with the lowest
 258          * reg.  This attempts to mimic existing PowerVM behaviour
 259          * (early debug does work there, despite having no vty with
 260          * reg==0. */
 261         return spapr_vty_get_default(spapr->vio_bus);
 262     }
 263
 264     if (!object_dynamic_cast(OBJECT(sdev), TYPE_VIO_SPAPR_VTY_DEVICE)) {
 265         return NULL;
 266     }
 267
 268     return sdev;
 269 }
 270
 271 static void spapr_vty_register_types(void)
 272 {
 273     spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
 274     spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
 275     type_register_static(&spapr_vty_info);
 276 }
 277
 278 type_init(spapr_vty_register_types)