From nobody Sat Nov 15 18:47:38 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=linaro.org ARC-Seal: i=1; a=rsa-sha256; t=1749590959; cv=none; d=zohomail.com; s=zohoarc; b=NGUEh81qCQ28ymS2MOemFyh6+CRKeSkFkeEiEL6NtfZ9V608l2gQt9ofRE8MDIeffFJueq+sLcLWSEZncBinFUFqZF/K5haNKKROg3zxwd9vjkp8JvgJSiY3SDfnMuEEtFaBQQ2zFMIhgxXl/RdTQB1j/INrYfTzFBartkkwk4s= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1749590959; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=AmunumSSbRJ+sU3cFReMs3+OMRURp5YZyylAlQXMnU4=; b=F23ZJkwGAf8M7wd7LKdf3lKEogtz+9aAdmT8Nf4L0GLcMTNbioedNleNwCqV25hsI/GPJKUVIXiRofIy/t/k+38q3ZGjfH0VED3i/95q/xqzIZEj9qbr7lAp9a8Ko3G4Wfih9f/WxLeLoZ5JMWv/h35z4wcdR5KVFr1PZIhoCdk= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1749590959701555.1699441913421; Tue, 10 Jun 2025 14:29:19 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uP6Wb-0005ZE-HD; Tue, 10 Jun 2025 17:28:53 -0400 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 1uP6WZ-0005X1-W9 for qemu-devel@nongnu.org; Tue, 10 Jun 2025 17:28:52 -0400 Received: from mail-pf1-x431.google.com ([2607:f8b0:4864:20::431]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1uP6WY-0000h6-Aq for qemu-devel@nongnu.org; Tue, 10 Jun 2025 17:28:51 -0400 Received: by mail-pf1-x431.google.com with SMTP id d2e1a72fcca58-739b3fe7ce8so4683598b3a.0 for ; Tue, 10 Jun 2025 14:28:49 -0700 (PDT) Received: from pc.. ([38.41.223.211]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7482b0c0613sm7864225b3a.122.2025.06.10.14.28.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Jun 2025 14:28:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1749590929; x=1750195729; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=AmunumSSbRJ+sU3cFReMs3+OMRURp5YZyylAlQXMnU4=; b=o82yPzcrblVxU8dJzGYt+3BSWBiyfC7sU1gXxTMpddwkvNGu7MnFJXkJPDaIiDbfpt ZKOIf0MNBrfwo4tceiCxQJnaL4DGL95RgVMmx/QeU29k+Mg3kKr7lGiD47b1vfgGkdzU 5r5yWsaFdhsrHsrlVTZe/n+dHtCEwwcIskQ8JIgOmDjTx4Qf771oAqp1Mo6GJh0iub+g oR52Ijms4uvWshF5jKaw5gS1uNhSaDqrSkqFqL9Lnik0b0/N3laFJupW0kWDqISNzGcX khH7MRcPUNRXEyEGMthtyED6OtPtjNEzrlwMR0/L3OVRIhupNni7aibbVJi9Dmp9x015 Pu/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749590929; x=1750195729; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=AmunumSSbRJ+sU3cFReMs3+OMRURp5YZyylAlQXMnU4=; b=tzb4ID+cPFLA38vsqPXgIWtNYJIluiW24Obb/VPTJjrbTRVGH5oOhZ1WtyaDyagh8s 9HIm+/Iuv3pwPMcT2mhhES9yEexbYHwyOMvNLZlehs6+/ZylMTAIrPiUyV8iS+lgmls6 fjcVrFKpUQP7TYDMxFG90hEq6LpnX3veQcbNxN6DH51vx4KZh39WSqQaqTsrUK7BYvTd XtTsJCejwiwOgI7yiWFpjRogNdubFJ87c2Q6bdnDIHQ3skI+blkJInh+uToMHG8VPrYI aI3n9dC8ESDmsdPJsJiyfGzefWCRRlmLmNT2eob85b1C2QbPSrYTaeikXQXBFwiUxm5d VIzA== X-Gm-Message-State: AOJu0YxvGGQbxmOUnE8zDVp3LsHI8EQ/2Y2TFoGP5uu8afMJ3voPVo6o BGxBx3roX9Ry1MfCCC/8JkGJlg2pZrC2lOvQvhnP8hJZaarPDO6GZ0wwtnE+tD6Y7u5PuzDbfwy 1AHUF X-Gm-Gg: ASbGncvsc1zW4EzfzIQoKZBLb66LqV17dA4rEbRhEa9jF5le3qSJWZxMq0tWKA+Wynf DoFNnvhPFFDDvoxuEMubOWATF/4/xvWxWAQFdmL7I1EAowtkQsJlaP4g9bDQcx48HXaofz3KxIe Vry3vOIVzIdq2fsNcBuTj1c1e24kn2D75MtqFRvdiM87aqsXlO7df73iI3SrWThxIKBSuDPXtn0 Rcr/e9sGDwGdgwF4IXF4AAo8fhd/+A6BMi/CO01D3fFcsHTC6UIKXIzkYJNSaVym4Er0NXzH71T COR12gRodmCQyeIAkH3ArCU23gkVImnmU+SLZwNZwOylCBpvT8g3LZWJVYzFMw== X-Google-Smtp-Source: AGHT+IG0MCbBo3/eYeGtX2/yHnPmAmOL4svxBBVWfPQUCvsq39e4hx0BWSwmeQ0OG6jpZgEODbCyKA== X-Received: by 2002:a05:6a00:1490:b0:73e:2d7a:8fc0 with SMTP id d2e1a72fcca58-7486cb219b7mr1312263b3a.1.1749590928721; Tue, 10 Jun 2025 14:28:48 -0700 (PDT) From: Pierrick Bouvier To: qemu-devel@nongnu.org Cc: philmd@linaro.org, berrange@redhat.com, peter.maydell@linaro.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= , richard.henderson@linaro.org, Thomas Huth , Paolo Bonzini , Pierrick Bouvier Subject: [PATCH 2/2] system/rtc: introduce -rtc time-dilation option Date: Tue, 10 Jun 2025 14:28:29 -0700 Message-ID: <20250610212829.2818792-3-pierrick.bouvier@linaro.org> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250610212829.2818792-1-pierrick.bouvier@linaro.org> References: <20250610212829.2818792-1-pierrick.bouvier@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::431; envelope-from=pierrick.bouvier@linaro.org; helo=mail-pf1-x431.google.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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=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: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1749590961639116600 Content-Type: text/plain; charset="utf-8" This option sets a factor on time spent for QEMU clocks since the beginning of execution. It can be used to slow or accelerate time for a guest, without impacting QEMU speed. Signed-off-by: Pierrick Bouvier --- system/rtc.c | 11 +++++++++++ system/vl.c | 3 +++ qemu-options.hx | 7 ++++++- 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/system/rtc.c b/system/rtc.c index 56951288c40..36c53f0fbd7 100644 --- a/system/rtc.c +++ b/system/rtc.c @@ -188,4 +188,15 @@ void configure_rtc(QemuOpts *opts) exit(1); } } + value =3D qemu_opt_get(opts, "time-dilation"); + if (value) { + if (qemu_strtod_finite(value, NULL, &clock_time_dilation)) { + error_report("invalid time-dilation factor '%s'", value); + exit(1); + } + if (clock_time_dilation <=3D 0.0f) { + error_report("time-dilation factor must be strictly positive"); + exit(1); + } + } } diff --git a/system/vl.c b/system/vl.c index 3b7057e6c66..e3e3f2f0209 100644 --- a/system/vl.c +++ b/system/vl.c @@ -243,6 +243,9 @@ static QemuOptsList qemu_rtc_opts =3D { },{ .name =3D "driftfix", .type =3D QEMU_OPT_STRING, + },{ + .name =3D "time-dilation", + .type =3D QEMU_OPT_STRING, }, { /* end of list */ } }, diff --git a/qemu-options.hx b/qemu-options.hx index 4faad5604c0..b8aaf8b3349 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4887,7 +4887,7 @@ SRST ERST =20 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \ - "-rtc [base=3Dutc|localtime|][,clock=3Dhost|rt|vm][,driftfix= =3Dnone|slew]\n" \ + "-rtc [base=3Dutc|localtime|][,clock=3Dhost|rt|vm][,driftfix= =3Dnone|slew][,time-dilation=3Dvalue]\n" \ " set the RTC base and clock, enable drift fix for cloc= k ticks (x86 only)\n", QEMU_ARCH_ALL) =20 @@ -4916,6 +4916,11 @@ SRST problems, specifically with Windows' ACPI HAL. This option will try to figure out how many timer interrupts were not processed by the Windows guest and will re-inject them. + + It's possible to slow or accelerate time using ``time-dilation``, + which is a factor (real number) applied to QEMU clock. A value of 0.1 = will + slow time by a factor of 10, and a value of 10 will accelerate it with= the + same factor. ERST =20 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ --=20 2.47.2