V2 changes:
-implement "tee" as a new backend. V1 implemented "tee" as a option.
-add documentation in qemu-options.hx.
Please review. Thanks.
---
qemu-char.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
qemu-config.c | 6 ++
qemu-options.hx | 25 ++++++++-
3 files changed, 197 insertions(+), 2 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index fb13b28..99e49a9 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -228,6 +228,156 @@ static CharDriverState *qemu_chr_open_null(QemuOpts *opts)
return chr;
}
+/* Tee driver */
+typedef struct {
+ CharDriverState *basechr; /* base io*/
+ CharDriverState *filechr; /* duplicate output to file */
+} TeeDriver;
+
+static void tee_init(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->init) {
+ s->basechr->init(s->basechr);
+ }
+ if (s->filechr->init) {
+ s->filechr->init(s->filechr);
+ }
+}
+
+static void tee_chr_update_read_handler(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ qemu_chr_add_handlers(s->basechr, chr->chr_can_read, chr->chr_read,
+ chr->chr_event, chr->handler_opaque);
+}
+
+/* tee_chr_write will return the write result of basechr, write result to file
+ * will be ignored. FIX ME. */
+static int tee_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->filechr->chr_write) {
+ s->filechr->chr_write(s->filechr, buf, len);
+ }
+ if (s->basechr->chr_write) {
+ return s->basechr->chr_write(s->basechr, buf, len);
+ }
+ return 0;
+}
+
+static void tee_chr_close(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_close) {
+ s->basechr->chr_close(s->basechr);
+ }
+ if (s->filechr->chr_close) {
+ s->filechr->chr_close(s->filechr);
+ }
+ qemu_free(s);
+}
+
+static int tee_chr_ioctl(CharDriverState *chr, int cmd, void *arg)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_ioctl) {
+ return s->basechr->chr_ioctl(s->basechr, cmd, arg);
+ }
+ return 0;
+}
+
+static int tee_get_msgfd(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->get_msgfd) {
+ return s->basechr->get_msgfd(s->basechr);
+ }
+ return -1;
+}
+
+static void tee_chr_send_event(CharDriverState *chr, int event)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_send_event) {
+ s->basechr->chr_send_event(s->basechr, event);
+ }
+}
+
+static void tee_chr_accept_input(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_accept_input) {
+ s->basechr->chr_accept_input(s->basechr);
+ }
+}
+static void tee_chr_set_echo(CharDriverState *chr, bool echo)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_set_echo) {
+ s->basechr->chr_set_echo(s->basechr, echo);
+ }
+}
+static void tee_chr_guest_open(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_guest_open) {
+ s->basechr->chr_guest_open(s->basechr);
+ }
+}
+static void tee_chr_guest_close(CharDriverState *chr)
+{
+ TeeDriver *s = chr->opaque;
+ if (s->basechr->chr_guest_close) {
+ s->basechr->chr_guest_close(s->basechr);
+ }
+}
+
+static CharDriverState *qemu_chr_open_tee(QemuOpts *opts)
+{
+ CharDriverState *chr;
+ TeeDriver *d;
+ CharDriverState *basechr;
+ CharDriverState *filechr;
+ const char *label = qemu_opts_id(opts);
+ const char *tee_fpath = qemu_opt_get(opts, "tee_fpath");
+ const char *tee_backend = qemu_opt_get(opts, "tee_backend");
+ char *new_label, *new_filename;
+ int sz;
+
+ chr = qemu_mallocz(sizeof(CharDriverState));
+ d = qemu_mallocz(sizeof(TeeDriver));
+
+ sz = strlen(label)+3;
+ new_label = qemu_malloc(sz);
+ snprintf(new_label, sz, "%s-0", label);
+ basechr = qemu_chr_open(new_label, tee_backend, NULL);
+
+ snprintf(new_label, sz, "%s-1", label);
+ sz = strlen(tee_fpath)+6;
+ new_filename = qemu_malloc(sz);
+ snprintf(new_filename, sz, "file:%s", tee_fpath);
+ filechr = qemu_chr_open(new_label, new_filename, NULL);
+ qemu_free(new_label);
+ qemu_free(new_filename);
+
+ d->basechr = basechr;
+ d->filechr = filechr;
+ chr->opaque = d;
+ chr->init = tee_init;
+ chr->chr_write = tee_chr_write;
+ chr->chr_close = tee_chr_close;
+ chr->chr_update_read_handler = tee_chr_update_read_handler;
+ chr->chr_ioctl = tee_chr_ioctl;
+ chr->get_msgfd = tee_get_msgfd;
+ chr->chr_send_event = tee_chr_send_event;
+ chr->chr_accept_input = tee_chr_accept_input;
+ chr->chr_set_echo = tee_chr_set_echo;
+ chr->chr_guest_open = tee_chr_guest_open;
+ chr->chr_guest_close = tee_chr_guest_close;
+
+ return chr;
+}
/* MUX driver for serial I/O splitting */
#define MAX_MUX 4
#define MUX_BUFFER_SIZE 32 /* Must be a power of 2. */
@@ -2356,6 +2506,16 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const
char *filename)
qemu_opt_set(opts, "mux", "on");
}
+ if (strstart(filename, "tee:",&p)) {
+ char tee_fpath[1024];
+ p = get_opt_value(tee_fpath, sizeof(tee_fpath), p);
+ filename = p+1;
+ qemu_opt_set(opts, "tee_backend", filename);
+ qemu_opt_set(opts, "tee_fpath", tee_fpath);
+ qemu_opt_set(opts, "backend", "tee");
+ return opts;
+ }
+
if (strcmp(filename, "null") == 0 ||
strcmp(filename, "pty") == 0 ||
strcmp(filename, "msmouse") == 0 ||
@@ -2468,6 +2628,7 @@ static const struct {
const char *name;
CharDriverState *(*open)(QemuOpts *opts);
} backend_table[] = {
+ { .name = "tee", .open = qemu_chr_open_tee },
{ .name = "null", .open = qemu_chr_open_null },
{ .name = "socket", .open = qemu_chr_open_socket },
{ .name = "udp", .open = qemu_chr_open_udp },
@@ -2536,7 +2697,12 @@ CharDriverState *qemu_chr_open_opts(QemuOpts *opts,
if (!chr->filename)
chr->filename = qemu_strdup(qemu_opt_get(opts, "backend"));
- chr->init = init;
+ if (strcmp(qemu_opt_get(opts, "backend"), "tee") == 0) {
+ TeeDriver *s = chr->opaque;
+ s->basechr->init = init;
+ } else {
+ chr->init = init;
+ }
QTAILQ_INSERT_TAIL(&chardevs, chr, next);
if (qemu_opt_get_bool(opts, "mux", 0)) {
diff --git a/qemu-config.c b/qemu-config.c
index c63741c..b82516f 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -151,6 +151,12 @@ static QemuOptsList qemu_chardev_opts = {
},{
.name = "debug",
.type = QEMU_OPT_NUMBER,
+ },{
+ .name = "tee_backend",
+ .type = QEMU_OPT_STRING,
+ },{
+ .name = "tee_fpath",
+ .type = QEMU_OPT_STRING,
},
{ /* end of list */ }
},
diff --git a/qemu-options.hx b/qemu-options.hx
index e6d7adc..1496f34 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1428,6 +1428,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
#if defined(CONFIG_SPICE)
"-chardev spicevmc,id=id,name=name[,debug=debug]\n"
#endif
+ "-chardev tee,id=id,tee_backend=dev_string,tee_fpath=path\n"
, QEMU_ARCH_ALL
)
@@ -1453,7 +1454,8 @@ Backend is one of:
@option{braille},
@option{tty},
@option{parport},
-@option{spicevmc}.
+@option{spicevmc},
+@option{tee}.
The specific backend will determine the applicable options.
All devices must have an id, which can be any string up to 127 characters
long.
@@ -1639,6 +1641,18 @@ required.
Connect to a spice virtual machine channel, such as vdiport.
#endif
+@item -chardev tee ,id=@var{id} ,tee_backend=@var{dev_string}
,tee_fpath=@var{path}
+
+@option{tee_backend} any kind of char device specified above. Double each comma
+in device string to ensure the whole device string is the option value, "id" in
+device string could be ignored. For example:
+tee_backend=stdio,,mux=on,,signal=on
+
+@option{tee_fpath} file path where char device output content is duplicated to.
+
+Connect to a device specified by dev_string, and duplicate output content of
+that device to a file.
+
@end table
ETEXI
@@ -1878,6 +1892,15 @@ A unix domain socket is used instead of a tcp socket.
The option works the
same as if you had specified @code{-serial tcp} except the unix domain socket
@var{path} is used for connections.
+@item tee:@var{path},@var{dev_string}
+Tee can duplicate output content of a serial device to a file.
+@var{path} is the file path where output content is duplicated to.
+@var{dev_string} should be any one of the serial devices specified
+above. An example would be:
+@table @code
+@item -serial tee:/var/log/test.log,pty
+@end table
+
@item mon:@var{dev_string}
This is a special option to allow the monitor to be multiplexed onto
another serial port. The monitor is accessed with key sequence of
