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 9335BCAC5B1 for ; Thu, 25 Sep 2025 15:49:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v1oD3-0007HR-L7; Thu, 25 Sep 2025 11:48:41 -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 1v1oCw-0007Fi-PJ for qemu-devel@nongnu.org; Thu, 25 Sep 2025 11:48:37 -0400 Received: from mgamail.intel.com ([198.175.65.20]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v1oCk-0005oE-0J for qemu-devel@nongnu.org; Thu, 25 Sep 2025 11:48:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1758815302; x=1790351302; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=6jRnfbN8/31Fw5rEfraQVnTTPcvtsXf+CfbhRcCHwDI=; b=CH1gQMWxauHupwOICb8QnKJVmJDaFLoUisR7Cy8O2YvIR51QscLcMhX8 EciwDRX6NHfur2CL3rQEowHZVup9jyWRTt0MU+2yu6q3aWKpJ38qeWpBL c/OvlVTDeCJIM9fTRjOwEEU8vpcLfljlfIrp1nQaQQ7jzeYszL1OV6eKI pohWsD+2Hb+YPpRSaqI591P+rDTpfyhq8NOydzpeIRNQ/rX7HbVEk6dvG b5fJsIB4axF8O1xT9PhjZnpO54D01SyCjeGMvvG1fm0zjZMW+DggPJHOJ kgEhAeYXH/7X8Oy0Em3hjLATzWAysDA589tDbrnhfrJ7vKhyUdazfuUK0 A==; X-CSE-ConnectionGUID: IArOiKsfQWCHzs5WrZEHjA== X-CSE-MsgGUID: fOS/onZ8TvihcjZqyNAOWg== X-IronPort-AV: E=McAfee;i="6800,10657,11564"; a="60838819" X-IronPort-AV: E=Sophos;i="6.18,292,1751266800"; d="scan'208";a="60838819" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2025 08:48:13 -0700 X-CSE-ConnectionGUID: VCemASL0SkyPxzDahHWoFw== X-CSE-MsgGUID: GWJO0FXkQ16UZ4Fmw65WbQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,292,1751266800"; d="scan'208";a="181375221" Received: from liuzhao-optiplex-7080.sh.intel.com (HELO localhost) ([10.239.160.39]) by orviesa003.jf.intel.com with ESMTP; 25 Sep 2025 08:48:13 -0700 Date: Fri, 26 Sep 2025 00:10:10 +0800 From: Zhao Liu To: Paolo Bonzini Cc: qemu-devel@nongnu.org, hector.cao@canonical.com, lk@c--e.de, berrange@redhat.com Subject: Re: [RFT PATCH v2 2/2] target/i386: add compatibility property for pdcm feature Message-ID: References: <20250923104136.133875-1-pbonzini@redhat.com> <20250923104136.133875-3-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250923104136.133875-3-pbonzini@redhat.com> Received-SPF: pass client-ip=198.175.65.20; envelope-from=zhao1.liu@intel.com; helo=mgamail.intel.com X-Spam_score_int: -47 X-Spam_score: -4.8 X-Spam_bar: ---- X-Spam_report: (-4.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Sep 23, 2025 at 12:41:36PM +0200, Paolo Bonzini wrote: > Date: Tue, 23 Sep 2025 12:41:36 +0200 > From: Paolo Bonzini > Subject: [RFT PATCH v2 2/2] target/i386: add compatibility property for > pdcm feature > X-Mailer: git-send-email 2.51.0 > > From: Hector Cao > > The pdcm feature is supposed to be disabled when PMU is not > available. Up until v10.1, pdcm feature is enabled even when PMU > is off. This behavior has been fixed but this change breaks the > migration of VMs that are run with QEMU < 10.0 and expect the pdcm > feature to be enabled on the destination host. > > This commit restores the legacy behavior for machines with version > prior to 10.1 to allow the migration from older QEMU to QEMU 10.1. > > Signed-off-by: Hector Cao > Link: https://lore.kernel.org/r/20250910115733.21149-3-hector.cao@canonical.com > Fixes: e68ec298090 ("i386/cpu: Move adjustment of CPUID_EXT_PDCM before feature_dependencies[] check", 2025-06-20) > [Move property from migration object to CPU. - Paolo] > Signed-off-by: Paolo Bonzini > --- > target/i386/cpu.h | 6 ++++++ > hw/i386/pc.c | 1 + > target/i386/cpu.c | 15 ++++++++++++--- > 3 files changed, 19 insertions(+), 3 deletions(-) Reviewed-by: Zhao Liu