From patchwork Fri Jun 7 20:19:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 249815 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A8B9D2C00A9 for ; Sat, 8 Jun 2013 06:22:34 +1000 (EST) Received: from localhost ([::1]:55860 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ul3BA-0004bS-5N for incoming@patchwork.ozlabs.org; Fri, 07 Jun 2013 16:22:32 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51840) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ul3At-0004bC-86 for qemu-devel@nongnu.org; Fri, 07 Jun 2013 16:22:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ul3Ar-0003gK-Ep for qemu-devel@nongnu.org; Fri, 07 Jun 2013 16:22:15 -0400 Received: from mail-ie0-x232.google.com ([2607:f8b0:4001:c03::232]:39279) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ul3Ar-0003ew-69; Fri, 07 Jun 2013 16:22:13 -0400 Received: by mail-ie0-f178.google.com with SMTP id at1so7995538iec.9 for ; Fri, 07 Jun 2013 13:22:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer; bh=tzCJ0RQ2cwgQlEWgghpFZITn+1SGiaCRpmWUfIzaMDI=; b=pArCaEKcy028fZF1BpVZE59s8DwdJV6M/WUJexGsBf75vfzI58pzuGoiKJUAwpROGK Cmu72DYvNbXQMMsrLLb4+3y7/pxyI3OBrE8092fosCQy/+M5HpPQ/Mc5JEDezocAGbfw upZkmz47DjOJIkbfY5FIVWh3iIfmqGyLpCrYOnJ1j0y0sGEkpUKNLAI+9kd2Vz834V6b sbPKO0n9WKLtYb0Jyn65kS0IiGpYRhHYzQ5JEw7NQAm/JIGrlqcP7+tkAMCqZ/f5DEtz 2gkBsQOzsphvnhJprjxaumALI9QvaayfVbeXrYi6dwNoLEtxtegWKBPmQYwZWY+K01tR nKqQ== X-Received: by 10.50.30.170 with SMTP id t10mr128014igh.95.1370636530748; Fri, 07 Jun 2013 13:22:10 -0700 (PDT) Received: from localhost ([32.97.110.51]) by mx.google.com with ESMTPSA id l14sm442143igf.9.2013.06.07.13.22.08 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 07 Jun 2013 13:22:10 -0700 (PDT) From: Michael Roth To: qemu-devel@nongnu.org Date: Fri, 7 Jun 2013 15:19:53 -0500 Message-Id: <1370636393-21044-1-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2607:f8b0:4001:c03::232 Cc: aliguori@us.ibm.com, s.priebe@profihost.ag, qemu-stable@nongnu.org, lcapitulino@redhat.com, hdegoede@redhat.com, kraxel@redhat.com, amit.shah@redhat.com Subject: [Qemu-devel] [PATCH v5] qemu-char: don't issue CHR_EVENT_OPEN in a BH X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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 Cc: qemu-stable@nongnu.org Signed-off-by: Michael Roth --- v4->v5: * fix segfault when using sdl/gtk console backends for monitor (Anthony) * rebased on latest origin/master v3->v4: * renamed 'suppress_be_open_on_init' to 'explicit_be_open' to match existing 'explicit_fe_open' flag (Hans) * added missing 'explicit_be_open' flags for spice vmc/port and msmouse backends v2->v3: * removed artifact in from v1 in backends/baum.c, test build with BRLAPI=y (Anthony) * rebased on latest origin/master v1->v2: * default to sending OPENED on backend init, add flag to suppress it (Anthony) * fix missing OPENED for stdio backends on w32 * fix missing OPENED when qemu_chr_new_from_opts() doesn't use qmp_chardev_add() * clean up/update commit message backends/baum.c | 2 -- backends/msmouse.c | 1 + include/sysemu/char.h | 2 +- qemu-char.c | 38 +++++++++++++++++--------------------- spice-qemu-char.c | 1 + ui/console.c | 4 ++++ ui/gtk.c | 2 ++ 7 files changed, 26 insertions(+), 24 deletions(-) diff --git a/backends/baum.c b/backends/baum.c index 4cba79f..62aa784 100644 --- a/backends/baum.c +++ b/backends/baum.c @@ -611,8 +611,6 @@ CharDriverState *chr_baum_init(void) qemu_set_fd_handler(baum->brlapi_fd, baum_chr_read, NULL, baum); - qemu_chr_be_generic_open(chr); - return chr; fail: diff --git a/backends/msmouse.c b/backends/msmouse.c index 0ac05a0..c0dbfcd 100644 --- a/backends/msmouse.c +++ b/backends/msmouse.c @@ -70,6 +70,7 @@ CharDriverState *qemu_chr_open_msmouse(void) chr = g_malloc0(sizeof(CharDriverState)); chr->chr_write = msmouse_chr_write; chr->chr_close = msmouse_chr_close; + chr->explicit_be_open = true; qemu_add_mouse_event_handler(msmouse_event, chr, 0, "QEMU Microsoft Mouse"); diff --git a/include/sysemu/char.h b/include/sysemu/char.h index 5e42c90..066c216 100644 --- a/include/sysemu/char.h +++ b/include/sysemu/char.h @@ -70,12 +70,12 @@ struct CharDriverState { void (*chr_set_echo)(struct CharDriverState *chr, bool echo); void (*chr_set_fe_open)(struct CharDriverState *chr, int fe_open); void *opaque; - int idle_tag; char *label; char *filename; int be_open; int fe_open; int explicit_fe_open; + int explicit_be_open; int avail_connections; QemuOpts *opts; QTAILQ_ENTRY(CharDriverState) next; diff --git a/qemu-char.c b/qemu-char.c index d04b429..0b6ae95 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -110,19 +110,9 @@ void qemu_chr_be_event(CharDriverState *s, int event) s->chr_event(s->handler_opaque, event); } -static gboolean qemu_chr_be_generic_open_bh(gpointer opaque) -{ - CharDriverState *s = opaque; - qemu_chr_be_event(s, CHR_EVENT_OPENED); - s->idle_tag = 0; - return FALSE; -} - void qemu_chr_be_generic_open(CharDriverState *s) { - if (s->idle_tag == 0) { - s->idle_tag = g_idle_add(qemu_chr_be_generic_open_bh, s); - } + qemu_chr_be_event(s, CHR_EVENT_OPENED); } int qemu_chr_fe_write(CharDriverState *s, const uint8_t *buf, int len) @@ -247,6 +237,7 @@ static CharDriverState *qemu_chr_open_null(void) chr = g_malloc0(sizeof(CharDriverState)); chr->chr_write = null_chr_write; + chr->explicit_be_open = true; return chr; } @@ -504,9 +495,6 @@ static CharDriverState *qemu_chr_open_mux(CharDriverState *drv) /* Frontend guest-open / -close notification is not support with muxes */ chr->chr_set_fe_open = NULL; - /* Muxes are always open on creation */ - qemu_chr_be_generic_open(chr); - return chr; } @@ -883,8 +871,6 @@ static CharDriverState *qemu_chr_open_fd(int fd_in, int fd_out) chr->chr_update_read_handler = fd_chr_update_read_handler; chr->chr_close = fd_chr_close; - qemu_chr_be_generic_open(chr); - return chr; } @@ -1243,6 +1229,7 @@ static CharDriverState *qemu_chr_open_pty(const char *id, chr->chr_update_read_handler = pty_chr_update_read_handler; chr->chr_close = pty_chr_close; chr->chr_add_watch = pty_chr_add_watch; + chr->explicit_be_open = true; s->fd = io_channel_from_fd(master_fd); s->timer_tag = 0; @@ -1595,8 +1582,6 @@ static CharDriverState *qemu_chr_open_pp_fd(int fd) chr->chr_close = pp_close; chr->opaque = drv; - qemu_chr_be_generic_open(chr); - return chr; } #endif /* __linux__ */ @@ -1650,6 +1635,7 @@ static CharDriverState *qemu_chr_open_pp_fd(int fd) chr->opaque = (void *)(intptr_t)fd; chr->chr_write = null_chr_write; chr->chr_ioctl = pp_ioctl; + chr->explicit_be_open = true; return chr; } #endif @@ -1880,7 +1866,6 @@ static CharDriverState *qemu_chr_open_win_path(const char *filename) g_free(chr); return NULL; } - qemu_chr_be_generic_open(chr); return chr; } @@ -1980,7 +1965,6 @@ static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts) g_free(chr); return NULL; } - qemu_chr_be_generic_open(chr); return chr; } @@ -1994,7 +1978,6 @@ static CharDriverState *qemu_chr_open_win_file(HANDLE fd_out) s->hcom = fd_out; chr->opaque = s; chr->chr_write = win_chr_write; - qemu_chr_be_generic_open(chr); return chr; } @@ -2329,6 +2312,8 @@ static CharDriverState *qemu_chr_open_udp_fd(int fd) chr->chr_write = udp_chr_write; chr->chr_update_read_handler = udp_chr_update_read_handler; chr->chr_close = udp_chr_close; + /* be isn't opened until we get a connection */ + chr->explicit_be_open = true; return chr; } @@ -2731,6 +2716,8 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, chr->get_msgfd = tcp_get_msgfd; chr->chr_add_client = tcp_chr_add_client; chr->chr_add_watch = tcp_chr_add_watch; + /* be isn't opened until we get a connection */ + chr->explicit_be_open = true; if (is_listen) { s->listen_fd = fd; @@ -3325,6 +3312,12 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts, if (!chr->filename) chr->filename = g_strdup(qemu_opt_get(opts, "backend")); chr->init = init; + /* if we didn't create the chardev via qmp_chardev_add, we + * need to send the OPENED event here + */ + if (!chr->explicit_be_open) { + qemu_chr_be_event(chr, CHR_EVENT_OPENED); + } QTAILQ_INSERT_TAIL(&chardevs, chr, next); if (qemu_opt_get_bool(opts, "mux", 0)) { @@ -3804,6 +3797,9 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend, if (!chr->filename) { chr->filename = g_strdup(ChardevBackendKind_lookup[backend->kind]); } + if (!chr->explicit_be_open) { + qemu_chr_be_event(chr, CHR_EVENT_OPENED); + } QTAILQ_INSERT_TAIL(&chardevs, chr, next); return ret; } else { diff --git a/spice-qemu-char.c b/spice-qemu-char.c index f10970c..6d147a7 100644 --- a/spice-qemu-char.c +++ b/spice-qemu-char.c @@ -255,6 +255,7 @@ static CharDriverState *chr_open(const char *subtype) 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); diff --git a/ui/console.c b/ui/console.c index b30853f..28bba6d 100644 --- a/ui/console.c +++ b/ui/console.c @@ -1788,6 +1788,10 @@ static CharDriverState *text_console_init(ChardevVC *vc) s->chr = chr; chr->opaque = s; chr->chr_set_echo = text_console_set_echo; + /* console/chardev init sometimes completes elsewhere in a 2nd + * stage, so defer OPENED events until they are fully initialized + */ + chr->explicit_be_open = true; if (display_state) { text_console_do_init(chr, display_state); diff --git a/ui/gtk.c b/ui/gtk.c index 3bc2842..1fff798 100644 --- a/ui/gtk.c +++ b/ui/gtk.c @@ -1119,6 +1119,8 @@ static CharDriverState *gd_vc_handler(ChardevVC *unused) chr = g_malloc0(sizeof(*chr)); chr->chr_write = gd_vc_chr_write; + /* defer OPENED events until our vc is fully initialized */ + chr->explicit_be_open = true; vcs[nb_vcs++] = chr;