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 2B684CF34B2 for ; Wed, 19 Nov 2025 14:45:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vLjQP-0008Hd-Ow; Wed, 19 Nov 2025 09:44:49 -0500 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 1vLjQN-0008HO-T9 for qemu-devel@nongnu.org; Wed, 19 Nov 2025 09:44:48 -0500 Received: from mgamail.intel.com ([192.198.163.7]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vLjQM-000535-4w for qemu-devel@nongnu.org; Wed, 19 Nov 2025 09:44:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1763563486; x=1795099486; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=N6/4xLkXn/UEsjhCQ0rtAQhE9Mcq6+4eeh/G/2p2EYA=; b=jzz6LLolC0eF/QBlAc4NKSM77xGXXWfn2bcaaqgNhgttTxSPsNUux9G4 YbUmeIKraZP1/UY5Q7GNixaAfhtozrHdMoLAtbT482wXv+T5lb4vp4/cI LyU0GYeeJBF2kzFQ2BXwjpchuyr3rjZR5xTtyNepzp+TTqFxMQXm67uxm xh7g8PtiR06mgVc/8tBeOkLT6CrmcErvS87V7GCJzBDG3hKwA4TljaqQ2 FWXwEZh0dZ5Q//p2vyD9GRr9v+GExeuYEhOl8jQJTLOlczfhhKNelj2Vs 7VQJ2HeoSSyXffjfmtEOB+YeDgT6fJFkDGg1qx3b5GwRjXtOiNI4YpDO+ Q==; X-CSE-ConnectionGUID: QOp7oVkHTWWcwocryGk5/A== X-CSE-MsgGUID: jiO2mcUeQyabRU044PCqQQ== X-IronPort-AV: E=McAfee;i="6800,10657,11618"; a="91082585" X-IronPort-AV: E=Sophos;i="6.19,315,1754982000"; d="scan'208";a="91082585" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Nov 2025 06:44:43 -0800 X-CSE-ConnectionGUID: IRbRyXrBRtKbHD29jB3LWQ== X-CSE-MsgGUID: YlQhc8LMSSygkk8R2zWyqQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,315,1754982000"; d="scan'208";a="191323730" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.240.78]) ([10.124.240.78]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Nov 2025 06:44:41 -0800 Message-ID: <2c0589f9-f3aa-44ac-b8c8-8c518cc751de@intel.com> Date: Wed, 19 Nov 2025 22:44:38 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/8] kvm: Detect guest-memfd flags supported To: Peter Xu Cc: qemu-devel@nongnu.org, Paolo Bonzini , Fabiano Rosas , Chenyi Qiang , David Hildenbrand , Alexey Kardashevskiy , Juraj Marcin References: <20251023185913.2923322-1-peterx@redhat.com> <20251023185913.2923322-4-peterx@redhat.com> <30f9d0b9-0a27-4b78-9633-8912bc18998b@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 Received-SPF: pass client-ip=192.198.163.7; envelope-from=xiaoyao.li@intel.com; helo=mgamail.intel.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.999, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_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 11/14/2025 5:19 AM, Peter Xu wrote: > On Thu, Nov 13, 2025 at 04:15:50PM -0500, Peter Xu wrote: >> On Fri, Oct 24, 2025 at 11:52:01AM +0800, Xiaoyao Li wrote: >>>> @@ -2781,6 +2782,11 @@ static int kvm_init(AccelState *as, MachineState *ms) >>>> kvm_supported_memory_attributes = kvm_vm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES); >>>> kvm_guest_memfd_supported = kvm_vm_check_extension(s, KVM_CAP_GUEST_MEMFD) && >>>> kvm_vm_check_extension(s, KVM_CAP_USER_MEMORY2); >>>> + ret = kvm_vm_check_extension(s, KVM_CAP_GUEST_MEMFD_FLAGS); >>>> + if (ret > 0) >>>> + kvm_guest_memfd_flags_supported = (uint64_t)ret; >>>> + else >>>> + kvm_guest_memfd_flags_supported = 0; >>> >>> Nit: >>> 1. QEMU's coding style always requires curly braces. >>> 2. is the (uint64_t) necessary? >>> 3. can we name it "kvm_supported_guest_memfd_flags" to make it consistent >>> with "kvm_supported_memory_attributes"? >>> >>> so how about >>> >>> kvm_supported_guest_memfd_flags = kvm_vm_check_extension(s, >>> KVM_CAP_GUEST_MEMFD_FLAGS); >>> if (kvm_supported_guest_memfd_flags < 0) { >>> kvm_supported_guest_memfd_flags = 0; >>> } >> >> Yep this looks good, I'll use it, thanks. > > About naming: note that we already have different styles (both below > variables introduced by your previous commits): > > static uint64_t kvm_supported_memory_attributes; > static bool kvm_guest_memfd_supported; The kvm_supported_* is for multiple bits, while kvm_*_supported is for a boolean. > I personally preferred kvm_guest_memfd* as prefix, so I kept it. I'm fine with it.