From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEE49270EDD for ; Tue, 1 Jul 2025 11:12:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751368371; cv=none; b=BVYjLRNFoiCMrDGlpDFJbbcnWPm7gzYRunRUXjPJdNEMI6PYiWYuI8nBnLoSg/SxVaadxSTcVRg2A2N8bOJBWxoMxCzhzpRfu360iJ5MbJUd0uL2zpaIaoI8vQ7ExiOYmdZpn83HzBPRQKEX10Nse4QUVDwei6YFquVnlZ84m/k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751368371; c=relaxed/simple; bh=xFhPSyGkeq1HsapYZVzfhrWmcZVtRpfUOIl6ai+xeUs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YFl9G3GoKgPCshxn+pbpiRJ7l/0U3+a79MamgsrV/cKBiJDh1xWShBooivv5+fzxcihrm2+wcUqJEXyCgrc3wU+8e56cEBNro9LSQWUndy1rf1kaf/w6JvaQhE/ZNUhc7AvevdlUH+tZEb28s68L1QsWg9svomkukhM5fxMVoBA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=FICxFd9O; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="FICxFd9O" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1751368370; x=1782904370; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=xFhPSyGkeq1HsapYZVzfhrWmcZVtRpfUOIl6ai+xeUs=; b=FICxFd9O+6XD87++6BUUEnA3GmaldGWQ5q8Gfg6EMJP69f/Fyv5BJUud QqrQatKUh9y59cXoCwKG45ocdilYkIGPwgosFASqwwEKXq3eNHDJ5u4Yf oVIxC0AN1vRRYMBwu2Mf9Cyu+i2crIqDQopRxcX3EanYSy/1rYmxYW4WF xhU8JZb1yc1of0OE15JPhk1hhxH7M6SUnB0iqrwWlz1gv3AaSu9ZiNixC TQojNzBiCvi3hh1IuTmW6W+xZ9nfUaSfyy9wUiAe+dkapv44UIFh3DfPt YTH+sUYdl8nDUkk5xV0E1LZKjV903L9Fj589HjDd5Tm+b+wucd57HRc2z g==; X-CSE-ConnectionGUID: f8PQQPGYQRCdd/wcS+IQ2A== X-CSE-MsgGUID: 7OG0yOmfT6SYqQqZLxGyqw== X-IronPort-AV: E=McAfee;i="6800,10657,11480"; a="53350492" X-IronPort-AV: E=Sophos;i="6.16,279,1744095600"; d="scan'208";a="53350492" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2025 04:12:49 -0700 X-CSE-ConnectionGUID: 98BTe/sSTTyiYlmlyG8Eyg== X-CSE-MsgGUID: 0C+mcSFoTUu017pGnoEkVA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,279,1744095600"; d="scan'208";a="153906309" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.247.1]) ([10.124.247.1]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2025 04:12:47 -0700 Message-ID: Date: Tue, 1 Jul 2025 19:12:44 +0800 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] i386/cpu: ARCH_CAPABILITIES should not be advertised on AMD To: Zhao Liu , Alexandre Chartre Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, qemu-stable@nongnu.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, maciej.szmigiero@oracle.com, Sean Christopherson , kvm@vger.kernel.org References: <20250630133025.4189544-1-alexandre.chartre@oracle.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/1/2025 6:26 PM, Zhao Liu wrote: >> unless it was explicitly requested by the user. > But this could still break Windows, just like issue #3001, which enables > arch-capabilities for EPYC-Genoa. This fact shows that even explicitly > turning on arch-capabilities in AMD Guest and utilizing KVM's emulated > value would even break something. > > So even for named CPUs, arch-capabilities=on doesn't reflect the fact > that it is purely emulated, and is (maybe?) harmful. It is because Windows adds wrong code. So it breaks itself and it's just the regression of Windows. KVM and QEMU are not supposed to be blamed.