qemu/spice-qemu-char.c
Michael Roth bd5c51ee6c qemu-char: don't issue CHR_EVENT_OPEN in a BH
When CHR_EVENT_OPENED was initially added, it was CHR_EVENT_RESET,
and it was issued as a bottom-half:

86e94dea5b

Which we basically used to print out a greeting/prompt for the
monitor.

AFAICT the only reason this was ever done in a BH was because in
some cases we'd modify the chr_write handler for a new chardev
backend *after* the site where we issued the reset (see:
86e94d:qemu_chr_open_stdio())

At some point this event was renamed to CHR_EVENT_OPENED, and we've
maintained the use of this BH ever since.

However, due to 9f939df955, we schedule
the BH via g_idle_add(), which is causing events to sometimes be
delivered after we've already begun processing data from backends,
leading to:

 known bugs:

  QMP:
    session negotation resets with OPENED event, in some cases this
    is causing new sessions to get sporadically reset

 potential bugs:

  hw/usb/redirect.c:
    can_read handler checks for dev->parser != NULL, which may be
    true if CLOSED BH has not been executed yet. In the past, OPENED
    quiesced outstanding CLOSED events prior to us reading client
    data. If it's delayed, our check may allow reads to occur even
    though we haven't processed the OPENED event yet, and when we
    do finally get the OPENED event, our state may get reset.

  qtest.c:
    can begin session before OPENED event is processed, leading to
    a spurious reset of the system and irq_levels

  gdbstub.c:
    may start a gdb session prior to the machine being paused

To fix these, let's just drop the BH.

Since the initial reasoning for using it still applies to an extent,
work around that by deferring the delivery of CHR_EVENT_OPENED until
after the chardevs have been fully initialized, toward the end of
qmp_chardev_add() (or some cases, qemu_chr_new_from_opts()). This
defers delivery long enough that we can be assured a CharDriverState
is fully initialized before CHR_EVENT_OPENED is sent.

Also, rather than requiring each chardev to do an explicit open, do it
automatically, and allow the small few who don't desire such behavior to
suppress the OPENED-on-init behavior by setting a 'explicit_be_open'
flag.

We additionally add missing OPENED events for stdio backends on w32,
which were previously not being issued, causing us to not recieve the
banner and initial prompts for qmp/hmp.

Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Message-id: 1370636393-21044-1-git-send-email-mdroth@linux.vnet.ibm.com
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-06-10 11:38:37 -05:00

354 lines
8.8 KiB
C

#include "config-host.h"
#include "trace.h"
#include "ui/qemu-spice.h"
#include "sysemu/char.h"
#include <spice.h>
#include <spice-experimental.h>
#include <spice/protocol.h>
#include "qemu/osdep.h"
typedef struct SpiceCharDriver {
CharDriverState* chr;
SpiceCharDeviceInstance sin;
char *subtype;
bool active;
bool blocked;
const uint8_t *datapos;
int datalen;
QLIST_ENTRY(SpiceCharDriver) next;
} SpiceCharDriver;
typedef struct SpiceCharSource {
GSource source;
SpiceCharDriver *scd;
} SpiceCharSource;
static QLIST_HEAD(, SpiceCharDriver) spice_chars =
QLIST_HEAD_INITIALIZER(spice_chars);
static int vmc_write(SpiceCharDeviceInstance *sin, const uint8_t *buf, int len)
{
SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
ssize_t out = 0;
ssize_t last_out;
uint8_t* p = (uint8_t*)buf;
while (len > 0) {
int can_write = qemu_chr_be_can_write(scd->chr);
last_out = MIN(len, can_write);
if (last_out <= 0) {
break;
}
qemu_chr_be_write(scd->chr, p, last_out);
out += last_out;
len -= last_out;
p += last_out;
}
trace_spice_vmc_write(out, len + out);
return out;
}
static int vmc_read(SpiceCharDeviceInstance *sin, uint8_t *buf, int len)
{
SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
int bytes = MIN(len, scd->datalen);
if (bytes > 0) {
memcpy(buf, scd->datapos, bytes);
scd->datapos += bytes;
scd->datalen -= bytes;
assert(scd->datalen >= 0);
}
if (scd->datalen == 0) {
scd->datapos = 0;
scd->blocked = false;
}
trace_spice_vmc_read(bytes, len);
return bytes;
}
#if SPICE_SERVER_VERSION >= 0x000c02
static void vmc_event(SpiceCharDeviceInstance *sin, uint8_t event)
{
SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
int chr_event;
switch (event) {
case SPICE_PORT_EVENT_BREAK:
chr_event = CHR_EVENT_BREAK;
break;
default:
return;
}
trace_spice_vmc_event(chr_event);
qemu_chr_be_event(scd->chr, chr_event);
}
#endif
static void vmc_state(SpiceCharDeviceInstance *sin, int connected)
{
SpiceCharDriver *scd = container_of(sin, SpiceCharDriver, sin);
if ((scd->chr->be_open && connected) ||
(!scd->chr->be_open && !connected)) {
return;
}
qemu_chr_be_event(scd->chr,
connected ? CHR_EVENT_OPENED : CHR_EVENT_CLOSED);
}
static SpiceCharDeviceInterface vmc_interface = {
.base.type = SPICE_INTERFACE_CHAR_DEVICE,
.base.description = "spice virtual channel char device",
.base.major_version = SPICE_INTERFACE_CHAR_DEVICE_MAJOR,
.base.minor_version = SPICE_INTERFACE_CHAR_DEVICE_MINOR,
.state = vmc_state,
.write = vmc_write,
.read = vmc_read,
#if SPICE_SERVER_VERSION >= 0x000c02
.event = vmc_event,
#endif
};
static void vmc_register_interface(SpiceCharDriver *scd)
{
if (scd->active) {
return;
}
scd->sin.base.sif = &vmc_interface.base;
qemu_spice_add_interface(&scd->sin.base);
scd->active = true;
trace_spice_vmc_register_interface(scd);
}
static void vmc_unregister_interface(SpiceCharDriver *scd)
{
if (!scd->active) {
return;
}
spice_server_remove_interface(&scd->sin.base);
scd->active = false;
trace_spice_vmc_unregister_interface(scd);
}
static gboolean spice_char_source_prepare(GSource *source, gint *timeout)
{
SpiceCharSource *src = (SpiceCharSource *)source;
*timeout = -1;
return !src->scd->blocked;
}
static gboolean spice_char_source_check(GSource *source)
{
SpiceCharSource *src = (SpiceCharSource *)source;
return !src->scd->blocked;
}
static gboolean spice_char_source_dispatch(GSource *source,
GSourceFunc callback, gpointer user_data)
{
GIOFunc func = (GIOFunc)callback;
return func(NULL, G_IO_OUT, user_data);
}
GSourceFuncs SpiceCharSourceFuncs = {
.prepare = spice_char_source_prepare,
.check = spice_char_source_check,
.dispatch = spice_char_source_dispatch,
};
static GSource *spice_chr_add_watch(CharDriverState *chr, GIOCondition cond)
{
SpiceCharDriver *scd = chr->opaque;
SpiceCharSource *src;
assert(cond == G_IO_OUT);
src = (SpiceCharSource *)g_source_new(&SpiceCharSourceFuncs,
sizeof(SpiceCharSource));
src->scd = scd;
return (GSource *)src;
}
static int spice_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
{
SpiceCharDriver *s = chr->opaque;
int read_bytes;
assert(s->datalen == 0);
s->datapos = buf;
s->datalen = len;
spice_server_char_device_wakeup(&s->sin);
read_bytes = len - s->datalen;
if (read_bytes != len) {
/* We'll get passed in the unconsumed data with the next call */
s->datalen = 0;
s->datapos = NULL;
s->blocked = true;
}
return read_bytes;
}
static void spice_chr_close(struct CharDriverState *chr)
{
SpiceCharDriver *s = chr->opaque;
vmc_unregister_interface(s);
QLIST_REMOVE(s, next);
g_free((char *)s->sin.subtype);
#if SPICE_SERVER_VERSION >= 0x000c02
g_free((char *)s->sin.portname);
#endif
g_free(s);
}
static void spice_chr_set_fe_open(struct CharDriverState *chr, int fe_open)
{
SpiceCharDriver *s = chr->opaque;
if (fe_open) {
vmc_register_interface(s);
} else {
vmc_unregister_interface(s);
}
}
static void print_allowed_subtypes(void)
{
const char** psubtype;
int i;
fprintf(stderr, "allowed names: ");
for(i=0, psubtype = spice_server_char_device_recognized_subtypes();
*psubtype != NULL; ++psubtype, ++i) {
if (i == 0) {
fprintf(stderr, "%s", *psubtype);
} else {
fprintf(stderr, ", %s", *psubtype);
}
}
fprintf(stderr, "\n");
}
static CharDriverState *chr_open(const char *subtype)
{
CharDriverState *chr;
SpiceCharDriver *s;
chr = g_malloc0(sizeof(CharDriverState));
s = g_malloc0(sizeof(SpiceCharDriver));
s->chr = chr;
s->active = false;
s->sin.subtype = g_strdup(subtype);
chr->opaque = s;
chr->chr_write = spice_chr_write;
chr->chr_add_watch = spice_chr_add_watch;
chr->chr_close = spice_chr_close;
chr->chr_set_fe_open = spice_chr_set_fe_open;
chr->explicit_be_open = true;
QLIST_INSERT_HEAD(&spice_chars, s, next);
return chr;
}
CharDriverState *qemu_chr_open_spice_vmc(const char *type)
{
const char **psubtype = spice_server_char_device_recognized_subtypes();
if (type == NULL) {
fprintf(stderr, "spice-qemu-char: missing name parameter\n");
print_allowed_subtypes();
return NULL;
}
for (; *psubtype != NULL; ++psubtype) {
if (strcmp(type, *psubtype) == 0) {
break;
}
}
if (*psubtype == NULL) {
fprintf(stderr, "spice-qemu-char: unsupported type: %s\n", type);
print_allowed_subtypes();
return NULL;
}
return chr_open(type);
}
#if SPICE_SERVER_VERSION >= 0x000c02
CharDriverState *qemu_chr_open_spice_port(const char *name)
{
CharDriverState *chr;
SpiceCharDriver *s;
if (name == NULL) {
fprintf(stderr, "spice-qemu-char: missing name parameter\n");
return NULL;
}
chr = chr_open("port");
s = chr->opaque;
s->sin.portname = g_strdup(name);
return chr;
}
void qemu_spice_register_ports(void)
{
SpiceCharDriver *s;
QLIST_FOREACH(s, &spice_chars, next) {
if (s->sin.portname == NULL) {
continue;
}
vmc_register_interface(s);
}
}
#endif
static void qemu_chr_parse_spice_vmc(QemuOpts *opts, ChardevBackend *backend,
Error **errp)
{
const char *name = qemu_opt_get(opts, "name");
if (name == NULL) {
error_setg(errp, "chardev: spice channel: no name given");
return;
}
backend->spicevmc = g_new0(ChardevSpiceChannel, 1);
backend->spicevmc->type = g_strdup(name);
}
static void qemu_chr_parse_spice_port(QemuOpts *opts, ChardevBackend *backend,
Error **errp)
{
const char *name = qemu_opt_get(opts, "name");
if (name == NULL) {
error_setg(errp, "chardev: spice port: no name given");
return;
}
backend->spiceport = g_new0(ChardevSpicePort, 1);
backend->spiceport->fqdn = g_strdup(name);
}
static void register_types(void)
{
register_char_driver_qapi("spicevmc", CHARDEV_BACKEND_KIND_SPICEVMC,
qemu_chr_parse_spice_vmc);
register_char_driver_qapi("spiceport", CHARDEV_BACKEND_KIND_SPICEPORT,
qemu_chr_parse_spice_port);
}
type_init(register_types);