From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (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 DF8443D9680; Wed, 5 Aug 2026 08:51:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785919895; cv=none; b=DtUM0ExM/Tdk3tWrmZLXSs4D9gg7JNHuXl7YE3xsUVfEFLZSJpYuH8K3soqsIZvO7tM6k7k/zEXxQ6ZBBe2zUQDo9AgUv9XOKMQd5NfB2VfaD6yOgVwxYIfpW3oy6phBhPKpIY/+b3M1Yfa72D9qCKr4q26xF10wNa4BBxmkfms= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785919895; c=relaxed/simple; bh=906UFDydbGu9lslP/ICAwTRGBdF+G9rFbkPozEz0hlg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Y9r02/hZzZ/yFRY+l4eRaIz8jYz9Nt8sKg3kBAWvQeXH9H8zX0UTGok8x7WDW0egCIouhh5/ejHKTy4Pa2zEspUXJPdgeYVrN2woUNkAdk7/wjSaNblXtYASFXzZyZBGOpU6Cr35YiZ7wL5WOSJb4Sa54rEQHOGxh5WkrNnn4AA= 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=CdykzEKh; arc=none smtp.client-ip=192.198.163.15 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="CdykzEKh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785919893; x=1817455893; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=906UFDydbGu9lslP/ICAwTRGBdF+G9rFbkPozEz0hlg=; b=CdykzEKhc42+Nti0stbtS7X1dG29jphW6pF+dAHEAM4K2QrX2MqAkCoI qVPSeiUXmcIQO9MfMVW/fACheBjLzzXaux6s4RnG4zozbYYuCaeamd3eW xeqpcR1P8bFW0xqkbqLtWKFkU6nu+VxliDxec6Hv0d2nMoWFfQ1bk8fgg yRv7t7ua0TiLjr1VbOWSlJnS9G7myuPTGoSoQ/jmkfQQTTD8Q/jhq706X qk8oOpE1aG/6p5xbC4egWaX3tgCn88I5CdQvU0GOlVAe84A/9lJ17yuog XkT8KPw5yg+ABFRz6egyynJ8KPcCLTl6A43Mp5hGt2EJ4zL13LhEmbMuA Q==; X-CSE-ConnectionGUID: Rqx5RGBeQ+63N3qA/+2XRQ== X-CSE-MsgGUID: rxxCj8zgQmeXKyfEpKawYQ== X-IronPort-AV: E=McAfee;i="6800,10657,11865"; a="86603454" X-IronPort-AV: E=Sophos;i="6.25,206,1779174000"; d="scan'208";a="86603454" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2026 01:51:32 -0700 X-CSE-ConnectionGUID: xl8+sgnqTkGG1UwygjFcIw== X-CSE-MsgGUID: MdQoRWnhTqKbstjwpzVllg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,206,1779174000"; d="scan'208";a="259988166" Received: from fuxiaogu-mobl1.ccr.corp.intel.com (HELO [10.238.208.47]) ([10.238.208.47]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Aug 2026 01:51:20 -0700 Message-ID: Date: Wed, 5 Aug 2026 16:51:17 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 03/41] KVM: Enumerate support for PRIVATE memory iff kvm_arch_has_private_mem is defined To: Ackerley Tng , aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev References: <20260728-gmem-inplace-conversion-v9-0-35f9aec2aed2@google.com> <20260728-gmem-inplace-conversion-v9-3-35f9aec2aed2@google.com> <7dafaa90-f3d4-4be4-a5cc-472163f18040@intel.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 7/31/2026 4:34 AM, Ackerley Tng wrote: > I think another way to phrase this is that if we don't make this change, > say, on the foo architecture where there's no CoCo and no private mem > support, kvm_supported_mem_attributes() would return true for the !kvm > case, which is over-reporting. Under the condition that the foo architecture enables CONFIG_KVM_VM_MEMORY_ATTRIBUTES. > How about this, replacing the entire changelog paragraph above: > > Explicitly guard reporting support for KVM_MEMORY_ATTRIBUTE_PRIVATE > based on kvm_arch_has_private_mem being #defined. This improves > reporting accuracy by not reporting support for > KVM_MEMORY_ATTRIBUTE_PRIVATE when kvm_supported_mem_attributes() is > called with kvm == NULL. It doesn't help for the case where kvm == NULL, but help for the case where CONFIG_KVM_VM_MEMORY_ATTRIBUTES is defined but kvm_arch_has_private_mem not. sorry for being picky. I think we can say This improves the reporting accuracy by avoiding the case where KVM_MEMORY_ATTRIBUTE_PRIVATE is reported when kvm == null even without kvm_arch_has_private_mem being #defined. > Give architectures full control over overriding the default definition > of kvm_arch_has_private_mem() by removing the coupling with > CONFIG_KVM_VM_MEMORY_ATTRIBUTES. > > In a later patch, kvm_arch_has_private_mem() will be defined based on > whether architectural features are compiled in, and made orthogonal to > CONFIG_KVM_VM_MEMORY_ATTRIBUTES.