From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8644EE73156 for ; Mon, 2 Feb 2026 11:26:55 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vms4l-0007zk-Dy; Mon, 02 Feb 2026 06:26:39 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vms4j-0007z5-K7 for qemu-devel@nongnu.org; Mon, 02 Feb 2026 06:26:37 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vms4i-0003uA-0q for qemu-devel@nongnu.org; Mon, 02 Feb 2026 06:26:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1770031593; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7XeXP9xjtbyMRKA0oW8Swmk/z4g3pkesjAoW3FA2fOM=; b=N+otIa9N3W87W6k2aTexE1QcOU5of47Yrk2pHi/SU4zhQVKPaoYeiTmzQDqYUHuOqBVWza 42SFMn30UEefifbTY/b/Rvfyg+NnB+D9ELH2f5umBf5+4pGBYJKLus/tQ3sufHEATTYS62 /c5dnkFSlkh4e4h0Wz0G1lmAsVhhhNM= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-613-y_MveZwtMG2edo1jUGPx5g-1; Mon, 02 Feb 2026 06:26:30 -0500 X-MC-Unique: y_MveZwtMG2edo1jUGPx5g-1 X-Mimecast-MFC-AGG-ID: y_MveZwtMG2edo1jUGPx5g_1770031589 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EFDAC180034A; Mon, 2 Feb 2026 11:26:28 +0000 (UTC) Received: from redhat.com (unknown [10.45.226.68]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4ABE430001A7; Mon, 2 Feb 2026 11:26:24 +0000 (UTC) Date: Mon, 2 Feb 2026 11:26:20 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Vladimir Sementsov-Ogievskiy Cc: marcandre.lureau@redhat.com, pbonzini@redhat.com, armbru@redhat.com, eblake@redhat.com, yc-core@yandex-team.ru, d-tatianin@yandex-team.ru, qemu-devel@nongnu.org, philmd@linaro.org Subject: Re: [PATCH v3 1/3] char: qemu_chr_write_log() use qemu_write_full() Message-ID: References: <20260201173633.413934-1-vsementsov@yandex-team.ru> <20260201173633.413934-2-vsementsov@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260201173633.413934-2-vsementsov@yandex-team.ru> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.01, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Sun, Feb 01, 2026 at 08:36:29PM +0300, Vladimir Sementsov-Ogievskiy wrote: > logfd is blocking, so we don't need to care about EAGAIN. > Let's simply use qemu_write_full(). Are you sure logfd is always blocking ? It can be an FD passed in from outside QEMU, and off-hand, I'm not sure where we force that to be blocking. Though we could argue it is the client't fault if they passed a non-blocking FD to QEMU. NB, we can *not* assume logfd is a plain file as libvirt will pass in a pipe to send logging via virtlogd. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > chardev/char.c | 22 +++++----------------- > 1 file changed, 5 insertions(+), 17 deletions(-) > > diff --git a/chardev/char.c b/chardev/char.c > index 3e432195a5..64006a3119 100644 > --- a/chardev/char.c > +++ b/chardev/char.c > @@ -82,29 +82,17 @@ void qemu_chr_be_event(Chardev *s, QEMUChrEvent event) > CHARDEV_GET_CLASS(s)->chr_be_event(s, event); > } > > -/* Not reporting errors from writing to logfile, as logs are > - * defined to be "best effort" only */ > static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len) > { > - size_t done = 0; > - ssize_t ret; > - > if (s->logfd < 0) { > return; > } > > - while (done < len) { > - retry: > - ret = write(s->logfd, buf + done, len - done); > - if (ret == -1 && errno == EAGAIN) { > - g_usleep(100); > - goto retry; > - } > - > - if (ret <= 0) { > - return; > - } > - done += ret; > + if (qemu_write_full(s->logfd, buf, len) < len) { > + /* > + * qemu_write_full() is defined with G_GNUC_WARN_UNUSED_RESULT, > + * but logging is best‑effort, we do ignore errors. > + */ > } > } > > -- > 2.52.0 > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|