diff --git a/chardev/char-pty.c b/chardev/char-pty.c index cc2f7617fe..cbb21b76ae 100644 --- a/chardev/char-pty.c +++ b/chardev/char-pty.c @@ -29,6 +29,7 @@ #include "qemu/sockets.h" #include "qemu/error-report.h" #include "qemu/module.h" +#include "qemu/option.h" #include "qemu/qemu-print.h" #include "chardev/char-io.h" @@ -41,6 +42,7 @@ struct PtyChardev { int connected; GSource *timer_src; + char *path; }; typedef struct PtyChardev PtyChardev; @@ -204,6 +206,12 @@ static void char_pty_finalize(Object *obj) Chardev *chr = CHARDEV(obj); PtyChardev *s = PTY_CHARDEV(obj); + /* unlink symlink */ + if (s->path) { + unlink(s->path); + g_free(s->path); + } + pty_chr_state(chr, 0); object_unref(OBJECT(s->ioc)); pty_chr_timer_cancel(s); @@ -330,6 +338,7 @@ static void char_pty_open(Chardev *chr, int master_fd, slave_fd; char pty_name[PATH_MAX]; char *name; + char *path = backend->u.pty.data->path; master_fd = qemu_openpty_raw(&slave_fd, pty_name); if (master_fd < 0) { @@ -354,12 +363,36 @@ static void char_pty_open(Chardev *chr, g_free(name); s->timer_src = NULL; *be_opened = false; + + /* create symbolic link */ + if (path) { + int res = symlink(pty_name, path); + + if (res != 0) { + error_setg_errno(errp, errno, "Failed to create PTY symlink"); + } else { + s->path = g_strdup(path); + } + } +} + +static void char_pty_parse(QemuOpts *opts, ChardevBackend *backend, + Error **errp) +{ + const char *path = qemu_opt_get(opts, "path"); + ChardevPty *pty; + + backend->type = CHARDEV_BACKEND_KIND_PTY; + pty = backend->u.pty.data = g_new0(ChardevPty, 1); + qemu_chr_parse_common(opts, qapi_ChardevPty_base(pty)); + pty->path = g_strdup(path); } static void char_pty_class_init(ObjectClass *oc, void *data) { ChardevClass *cc = CHARDEV_CLASS(oc); + cc->parse = char_pty_parse; cc->open = char_pty_open; cc->chr_write = char_pty_chr_write; cc->chr_update_read_handler = pty_chr_update_read_handler; diff --git a/chardev/char.c b/chardev/char.c index 35623c78a3..c0cc52824b 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -428,6 +428,11 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename, qemu_opt_set(opts, "path", p, &error_abort); return opts; } + if (strstart(filename, "pty:", &p)) { + qemu_opt_set(opts, "backend", "pty", &error_abort); + qemu_opt_set(opts, "path", p, &error_abort); + return opts; + } if (strstart(filename, "tcp:", &p) || strstart(filename, "telnet:", &p) || strstart(filename, "tn3270:", &p) || diff --git a/qapi/char.json b/qapi/char.json index 42eda4f98b..e045354350 100644 --- a/qapi/char.json +++ b/qapi/char.json @@ -444,6 +444,20 @@ 'base': 'ChardevCommon', 'if': 'CONFIG_SPICE_PROTOCOL' } +## +# @ChardevPty: +# +# Configuration info for pty implementation. +# +# @path: optional path to create a symbolic link that points to the +# allocated PTY +# +# Since: 9.2 +## +{ 'struct': 'ChardevPty', + 'data': { '*path': 'str' }, + 'base': 'ChardevCommon' } + ## # @ChardevBackendKind: # @@ -655,6 +669,17 @@ { 'struct': 'ChardevRingbufWrapper', 'data': { 'data': 'ChardevRingbuf' } } + +## +# @ChardevPtyWrapper: +# +# @data: Configuration info for pty chardevs +# +# Since: 9.2 +## +{ 'struct': 'ChardevPtyWrapper', + 'data': { 'data': 'ChardevPty' } } + ## # @ChardevBackend: # @@ -675,7 +700,7 @@ 'pipe': 'ChardevHostdevWrapper', 'socket': 'ChardevSocketWrapper', 'udp': 'ChardevUdpWrapper', - 'pty': 'ChardevCommonWrapper', + 'pty': 'ChardevPtyWrapper', 'null': 'ChardevCommonWrapper', 'mux': 'ChardevMuxWrapper', 'msmouse': 'ChardevCommonWrapper', diff --git a/qemu-options.hx b/qemu-options.hx index 20a1ce0d43..d5afefe5b6 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3712,7 +3712,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" #else - "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev pty,id=id[,path=path][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" #endif #ifdef CONFIG_BRLAPI @@ -3951,12 +3951,22 @@ The available backends are: ``path`` specifies the name of the serial device to open. -``-chardev pty,id=id`` - Create a new pseudo-terminal on the host and connect to it. ``pty`` - does not take any options. +``-chardev pty,id=id[,path=path]`` + Create a new pseudo-terminal on the host and connect to it. ``pty`` is not available on Windows hosts. + If ``path`` is specified, QEMU will create a symbolic link at + that location which points to the new PTY device. + + This avoids having to make QMP or HMP monitor queries to find out + what the new PTY device path is. + + Note that while QEMU will remove the symlink when it exits + gracefully, it will not do so in case of crashes or on certain + startup errors. It is recommended that the user checks and removes + the symlink after QEMU terminates to account for this. + ``-chardev stdio,id=id[,signal=on|off]`` Connect to standard input and standard output of the QEMU process. @@ -4314,8 +4324,19 @@ SRST vc:80Cx24C - ``pty`` - [Linux only] Pseudo TTY (a new PTY is automatically allocated) + ``pty[:path]`` + [Linux only] Pseudo TTY (a new PTY is automatically allocated). + + If ``path`` is specified, QEMU will create a symbolic link at + that location which points to the new PTY device. + + This avoids having to make QMP or HMP monitor queries to find + out what the new PTY device path is. + + Note that while QEMU will remove the symlink when it exits + gracefully, it will not do so in case of crashes or on certain + startup errors. It is recommended that the user checks and + removes the symlink after QEMU terminates to account for this. ``none`` No device is allocated. Note that for machine types which