aboutsummaryrefslogtreecommitdiff
path: root/hw/char/spapr_vty.c
blob: 617303dbaf2ab8fea76060fda86aa8ef546300b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "cpu.h"
#include "hw/qdev.h"
#include "chardev/char-fe.h"
#include "hw/ppc/spapr.h"
#include "hw/ppc/spapr_vio.h"

#define VTERM_BUFSIZE   16

typedef struct SpaprVioVty {
    SpaprVioDevice sdev;
    CharBackend chardev;
    uint32_t in, out;
    uint8_t buf[VTERM_BUFSIZE];
} SpaprVioVty;

#define TYPE_VIO_SPAPR_VTY_DEVICE "spapr-vty"
#define VIO_SPAPR_VTY_DEVICE(obj) \
     OBJECT_CHECK(SpaprVioVty, (obj), TYPE_VIO_SPAPR_VTY_DEVICE)

static int vty_can_receive(void *opaque)
{
    SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(opaque);

    return VTERM_BUFSIZE - (dev->in - dev->out);
}

static void vty_receive(void *opaque, const uint8_t *buf, int size)
{
    SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(opaque);
    int i;

    if ((dev->in == dev->out) && size) {
        /* toggle line to simulate edge interrupt */
        qemu_irq_pulse(spapr_vio_qirq(&dev->sdev));
    }
    for (i = 0; i < size; i++) {
        if (dev->in - dev->out >= VTERM_BUFSIZE) {
            static bool reported;
            if (!reported) {
                error_report("VTY input buffer exhausted - characters dropped."
                             " (input size = %i)", size);
                reported = true;
            }
            break;
        }
        dev->buf[dev->in++ % VTERM_BUFSIZE] = buf[i];
    }
}

static int vty_getchars(SpaprVioDevice *sdev, uint8_t *buf, int max)
{
    SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(sdev);
    int n = 0;

    while ((n < max) && (dev->out != dev->in)) {
        buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];

        /* PowerVM's vty implementation has a bug where it inserts a
         * \0 after every \r going to the guest.  Existing guests have
         * a workaround for this which removes every \0 immediately
         * following a \r, so here we make ourselves bug-for-bug
         * compatible, so that the guest won't drop a real \0-after-\r
         * that happens to occur in a binary stream. */
        if (buf[n - 1] == '\r') {
            if (n < max) {
                buf[n++] = '\0';
            } else {
                /* No room for the extra \0, roll back and try again
                 * next time */
                dev->out--;
                n--;
                break;
            }
        }
    }

    qemu_chr_fe_accept_input(&dev->chardev);

    return n;
}

void vty_putchars(SpaprVioDevice *sdev, uint8_t *buf, int len)
{
    SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(sdev);

    /* XXX this blocks entire thread. Rewrite to use
     * qemu_chr_fe_write and background I/O callbacks */
    qemu_chr_fe_write_all(&dev->chardev, buf, len);
}

static void spapr_vty_realize(SpaprVioDevice *sdev, Error **errp)
{
    SpaprVioVty *dev = VIO_SPAPR_VTY_DEVICE(sdev);

    if (!qemu_chr_fe_backend_connected(&dev->chardev)) {
        error_setg(errp, "chardev property not set");
        return;
    }

    qemu_chr_fe_set_handlers(&dev->chardev, vty_can_receive,
                             vty_receive, NULL, NULL, dev, NULL, true);
}

/* Forward declaration */
static target_ulong h_put_term_char(PowerPCCPU *cpu, SpaprMachineState *spapr,
                                    target_ulong opcode, target_ulong *args)
{
    target_ulong reg = args[0];
    target_ulong len = args[1];
    target_ulong char0_7 = args[2];
    target_ulong char8_15 = args[3];
    SpaprVioDevice *sdev;
    uint8_t buf[16];

    sdev = vty_lookup(spapr, reg);
    if (!sdev) {
        return H_PARAMETER;
    }

    if (len > 16) {
        return H_PARAMETER;
    }

    *((uint64_t *)buf) = cpu_to_be64(char0_7);
    *((uint64_t *)buf + 1) = cpu_to_be64(char8_15);

    vty_putchars(sdev, buf, len);

    return H_SUCCESS;
}

static target_ulong h_get_term_char(PowerPCCPU *cpu, SpaprMachineState *spapr,
                                    target_ulong opcode, target_ulong *args)
{
    target_ulong reg = args[0];
    target_ulong *len = args + 0;
    target_ulong *char0_7 = args + 1;
    target_ulong *char8_15 = args + 2;
    SpaprVioDevice *sdev;
    uint8_t buf[16];

    sdev = vty_lookup(spapr, reg);
    if (!sdev) {
        return H_PARAMETER;
    }

    *len = vty_getchars(sdev, buf, sizeof(buf));
    if (*len < 16) {
        memset(buf + *len, 0, 16 - *len);
    }

    *char0_7 = be64_to_cpu(*((uint64_t *)buf));
    *char8_15 = be64_to_cpu(*((uint64_t *)buf + 1));

    return H_SUCCESS;
}

void spapr_vty_create(SpaprVioBus *bus, Chardev *chardev)
{
    DeviceState *dev;

    dev = qdev_create(&bus->bus, "spapr-vty");
    qdev_prop_set_chr(dev, "chardev", chardev);
    qdev_init_nofail(dev);
}

static Property spapr_vty_properties[] = {
    DEFINE_SPAPR_PROPERTIES(SpaprVioVty, sdev),
    DEFINE_PROP_CHR("chardev", SpaprVioVty, chardev),
    DEFINE_PROP_END_OF_LIST(),
};

static const VMStateDescription vmstate_spapr_vty = {
    .name = "spapr_vty",
    .version_id = 1,
    .minimum_version_id = 1,
    .fields = (VMStateField[]) {
        VMSTATE_SPAPR_VIO(sdev, SpaprVioVty),

        VMSTATE_UINT32(in, SpaprVioVty),
        VMSTATE_UINT32(out, SpaprVioVty),
        VMSTATE_BUFFER(buf, SpaprVioVty),
        VMSTATE_END_OF_LIST()
    },
};

static void spapr_vty_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    SpaprVioDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);

    k->realize = spapr_vty_realize;
    k->dt_name = "vty";
    k->dt_type = "serial";
    k->dt_compatible = "hvterm1";
    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
    dc->props = spapr_vty_properties;
    dc->vmsd = &vmstate_spapr_vty;
}

static const TypeInfo spapr_vty_info = {
    .name          = TYPE_VIO_SPAPR_VTY_DEVICE,
    .parent        = TYPE_VIO_SPAPR_DEVICE,
    .instance_size = sizeof(SpaprVioVty),
    .class_init    = spapr_vty_class_init,
};

SpaprVioDevice *spapr_vty_get_default(SpaprVioBus *bus)
{
    SpaprVioDevice *sdev, *selected;
    BusChild *kid;

    /*
     * To avoid the console bouncing around we want one VTY to be
     * the "default". We haven't really got anything to go on, so
     * arbitrarily choose the one with the lowest reg value.
     */

    selected = NULL;
    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
        DeviceState *iter = kid->child;

        /* Only look at VTY devices */
        if (!object_dynamic_cast(OBJECT(iter), TYPE_VIO_SPAPR_VTY_DEVICE)) {
            continue;
        }

        sdev = VIO_SPAPR_DEVICE(iter);

        /* First VTY we've found, so it is selected for now */
        if (!selected) {
            selected = sdev;
            continue;
        }

        /* Choose VTY with lowest reg value */
        if (sdev->reg < selected->reg) {
            selected = sdev;
        }
    }

    return selected;
}

SpaprVioDevice *vty_lookup(SpaprMachineState *spapr, target_ulong reg)
{
    SpaprVioDevice *sdev;

    sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
    if (!sdev && reg == 0) {
        /* Hack for kernel early debug, which always specifies reg==0.
         * We search all VIO devices, and grab the vty with the lowest
         * reg.  This attempts to mimic existing PowerVM behaviour
         * (early debug does work there, despite having no vty with
         * reg==0. */
        return spapr_vty_get_default(spapr->vio_bus);
    }

    if (!object_dynamic_cast(OBJECT(sdev), TYPE_VIO_SPAPR_VTY_DEVICE)) {
        return NULL;
    }

    return sdev;
}

static void spapr_vty_register_types(void)
{
    spapr_register_hypercall(H_PUT_TERM_CHAR, h_put_term_char);
    spapr_register_hypercall(H_GET_TERM_CHAR, h_get_term_char);
    type_register_static(&spapr_vty_info);
}

type_init(spapr_vty_register_types)