qemu/spice-qemu-char.c

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#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;
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: 86e94dea5b740dad65446c857f6959eae43e0ba6 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 9f939df955a4152aad69a19a77e0898631bb2c18, 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>
2013-06-08 00:19:53 +04:00
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();
Revert "qemu-char: Print strerror message on failure" and deps The commit's purpose is laudable: The only way for chardev drivers to communicate an error was to return a NULL pointer, which resulted in an error message that said _that_ something went wrong, but not _why_. It attempts to achieve it by changing the interface to return 0/-errno and update qemu_chr_open_opts() to use strerror() to display a more helpful error message. Unfortunately, it has serious flaws: 1. Backends "socket" and "udp" return bogus error codes, because qemu_chr_open_socket() and qemu_chr_open_udp() assume that unix_listen_opts(), unix_connect_opts(), inet_listen_opts(), inet_connect_opts() and inet_dgram_opts() fail with errno set appropriately. That assumption is wrong, and the commit turns unspecific error messages into misleading error messages. For instance: $ qemu-system-x86_64 -nodefaults -vnc :0 -chardev socket,id=bar,host=xxx inet_connect: host and/or port not specified chardev: opening backend "socket" failed: No such file or directory ENOENT is what happens to be in my errno when the backend returns -errno. Let's put ERANGE there just for giggles: $ qemu-system-x86_64 -nodefaults -vnc :0 -chardev socket,id=bar,host=xxx -drive if=none,iops=99999999999999999999 inet_connect: host and/or port not specified chardev: opening backend "socket" failed: Numerical result out of range Worse: when errno happens to be zero, return -errno erroneously signals success, and qemu_chr_new_from_opts() dies dereferencing uninitialized chr. I observe this with "-serial unix:". 2. All qemu_chr_open_opts() knows about the error is an errno error code. That's simply not enough for a decent message. For instance, when inet_dgram() can't resolve the parameter host, which errno code should it use? What if it can't resolve parameter localaddr? Clue: many backends already report errors in their open methods. Let's revert the flawed commit along with its dependencies, and fix up the silent error paths instead. This reverts commit 6e1db57b2ac9025c2443c665a0d9e78748637b26. Conflicts: console.c hw/baum.c qemu-char.c This reverts commit aad04cd024f0c59f0b96f032cde2e24eb3abba6d. The parts of commit db418a0a "Add stdio char device on windows" that depend on the reverted change fixed up. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-02-07 18:09:08 +04:00
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();
Revert "qemu-char: Print strerror message on failure" and deps The commit's purpose is laudable: The only way for chardev drivers to communicate an error was to return a NULL pointer, which resulted in an error message that said _that_ something went wrong, but not _why_. It attempts to achieve it by changing the interface to return 0/-errno and update qemu_chr_open_opts() to use strerror() to display a more helpful error message. Unfortunately, it has serious flaws: 1. Backends "socket" and "udp" return bogus error codes, because qemu_chr_open_socket() and qemu_chr_open_udp() assume that unix_listen_opts(), unix_connect_opts(), inet_listen_opts(), inet_connect_opts() and inet_dgram_opts() fail with errno set appropriately. That assumption is wrong, and the commit turns unspecific error messages into misleading error messages. For instance: $ qemu-system-x86_64 -nodefaults -vnc :0 -chardev socket,id=bar,host=xxx inet_connect: host and/or port not specified chardev: opening backend "socket" failed: No such file or directory ENOENT is what happens to be in my errno when the backend returns -errno. Let's put ERANGE there just for giggles: $ qemu-system-x86_64 -nodefaults -vnc :0 -chardev socket,id=bar,host=xxx -drive if=none,iops=99999999999999999999 inet_connect: host and/or port not specified chardev: opening backend "socket" failed: Numerical result out of range Worse: when errno happens to be zero, return -errno erroneously signals success, and qemu_chr_new_from_opts() dies dereferencing uninitialized chr. I observe this with "-serial unix:". 2. All qemu_chr_open_opts() knows about the error is an errno error code. That's simply not enough for a decent message. For instance, when inet_dgram() can't resolve the parameter host, which errno code should it use? What if it can't resolve parameter localaddr? Clue: many backends already report errors in their open methods. Let's revert the flawed commit along with its dependencies, and fix up the silent error paths instead. This reverts commit 6e1db57b2ac9025c2443c665a0d9e78748637b26. Conflicts: console.c hw/baum.c qemu-char.c This reverts commit aad04cd024f0c59f0b96f032cde2e24eb3abba6d. The parts of commit db418a0a "Add stdio char device on windows" that depend on the reverted change fixed up. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-02-07 18:09:08 +04:00
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);