From nobody Thu Nov 6 06:29:37 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=gmail.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1539260904135198.75376642654032; Thu, 11 Oct 2018 05:28:24 -0700 (PDT) Received: from localhost ([::1]:34130 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAa4f-0007Ed-Sp for importer@patchew.org; Thu, 11 Oct 2018 08:28:17 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41251) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAa39-00064I-H8 for qemu-devel@nongnu.org; Thu, 11 Oct 2018 08:26:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAa38-00075i-FS for qemu-devel@nongnu.org; Thu, 11 Oct 2018 08:26:43 -0400 Received: from mail-lj1-x244.google.com ([2a00:1450:4864:20::244]:34456) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gAa38-00074w-7l for qemu-devel@nongnu.org; Thu, 11 Oct 2018 08:26:42 -0400 Received: by mail-lj1-x244.google.com with SMTP id j17-v6so8049502lja.1 for ; Thu, 11 Oct 2018 05:26:42 -0700 (PDT) Received: from localhost.localdomain ([77.221.221.49]) by smtp.gmail.com with ESMTPSA id 33-v6sm5713890lfu.64.2018.10.11.05.26.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 11 Oct 2018 05:26:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=gzWDSZUzWgGXQ9uuXM46zuT9yZpYXYodmEukxQ4Glsw=; b=Ridifx6PdY6q9N9AvlVuZfQ4mUj4UdFs8/F2byDysY8LDqNzD2BNeHmWnZLw4gO1DV rDhwp3IAi8jHb0OlZXhYBs7MP51HlQ5p8Jh89598pbAvl5R+HNAEQ/6ikR99uc/KuXcV 6rSMdEP6o3r2xms5uCgjduZywlhfBevjJ1MassV3MSXkosyCbTQCZdEtpMDBU+lX67zK mRp8AuwiEC2floTjjs9f+4D6SJB5DkJ34OAC5CCGSq/FXlUbA44F3lUgnnG4b1GRuGui 43riRU/pvMJP4lDxgA3JlL8DOEK9mlkWJ6c1qEcmtBDN+9TSeh+2/2M1lCGJj6YWnUX8 JIUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=gzWDSZUzWgGXQ9uuXM46zuT9yZpYXYodmEukxQ4Glsw=; b=gGp1neif1mfHVwK5t1dttKY9Bt5qqCfLAaCDWSQ88DkjyJ5V7Sb1Lg7M1anY6CI0VB M93YYeKrzxYKBrraBH2uibdytpu5Gyma9vyDQh9P1KR1NcKH41q8v8B/gbQccaVPUNTN TQG2hYqHytu2JBSGkjT01zBv4be8otn6PLVP0HVzMQo7gDpvmaCV0po+TdcT3ztW4NjA O8oJ8DJijmO/d4TCOr3DEDl4W0kKWKbgI5RxujDWesnodN4rLAMNayrRpLPKjcR1t6mn QgabOgi6rKOyIYn4Cr+U2QXWV+dDqjOq17S9zemsCC8w50lLcLBYt/jQTZhPY3eLD9yQ Vdvg== X-Gm-Message-State: ABuFfogMBpwouou1GYlFTFoaYgjguJrcUugvVe7GaMVJZz4RMaOQnBPl LWYHV/t/GjEPAtHNFynMYCNZ/tMB X-Google-Smtp-Source: ACcGV60CYddFMmEGstgEgktF3EbPtpW2w2JJs8y0o2u5TrkJfFS2r3ZJ20owMhVL1zlCQNWXCNoAHQ== X-Received: by 2002:a2e:6d0a:: with SMTP id i10-v6mr1189905ljc.14.1539260800501; Thu, 11 Oct 2018 05:26:40 -0700 (PDT) From: Artem Pisarenko To: qemu-devel@nongnu.org Date: Thu, 11 Oct 2018 18:23:16 +0600 Message-Id: <4088cc0a4affe3d68a3280013370fc9027fa6ccc.1539259394.git.artem.k.pisarenko@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4864:20::244 Subject: [Qemu-devel] [PATCH 1/4] vl: improve/fix documentation related to RTC function X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Artem Pisarenko Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDMRC_1 RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Documentation describing -rtc option updated to better match current implem= entation and highlight some important specifics. Signed-off-by: Artem Pisarenko --- qemu-options.hx | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/qemu-options.hx b/qemu-options.hx index f139459..4a9c065 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3458,25 +3458,29 @@ HXCOMM Silently ignored for compatibility DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL) =20 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ - "-rtc [base=3Dutc|localtime|date][,clock=3Dhost|rt|vm][,driftfix=3Dnon= e|slew]\n" \ + "-rtc [base=3Dutc|localtime|][,clock=3Dhost|rt|vm][,driftfix= =3Dnone|slew]\n" \ " set the RTC base and clock, enable drift fix for cloc= k ticks (x86 only)\n", QEMU_ARCH_ALL) =20 STEXI =20 -@item -rtc [base=3Dutc|localtime|@var{date}][,clock=3Dhost|vm][,driftfix= =3Dnone|slew] +@item -rtc [base=3Dutc|localtime|@var{datetime}][,clock=3Dhost|rt|vm][,dri= ftfix=3Dnone|slew] @findex -rtc Specify @option{base} as @code{utc} or @code{localtime} to let the RTC sta= rt at the current UTC or local time, respectively. @code{localtime} is required for correct = date in -MS-DOS or Windows. To start at a specific point in time, provide @var{date= } in the +MS-DOS or Windows. To start at a specific point in time, provide @var{date= time} in the format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base i= s UTC. =20 By default the RTC is driven by the host system time. This allows using of= the RTC as accurate reference clock inside the guest, specifically if the host time is smoothly following an accurate external reference clock, e.g. via = NTP. If you want to isolate the guest time from the host, you can set @option{c= lock} -to @code{rt} instead. To even prevent it from progressing during suspensi= on, -you can set it to @code{vm}. +to @code{rt} instead, which provides host monotonic clock if host support = it. +To even prevent it from progressing during suspension, you can set it to +@code{vm} (virtual clock). Virtual clock is the clock seen by guest, +In icount mode of emulation its (long term) speed will be different from +any host clock, when icount configured to non-auto value or virtual cpu sl= eeping +is off, and no synchronization algorithm is active. =20 Enable @option{driftfix} (i386 targets only) if you experience time drift = problems, specifically with Windows' ACPI HAL. This option will try to figure out how --=20 2.7.4