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 62737C52D71 for ; Fri, 9 Aug 2024 09:01:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1scLUC-000812-7p; Fri, 09 Aug 2024 05:00:36 -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 1scLUA-0007zs-1b for qemu-devel@nongnu.org; Fri, 09 Aug 2024 05:00:34 -0400 Received: from mail-wr1-x42d.google.com ([2a00:1450:4864:20::42d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1scLU7-0004s6-AS for qemu-devel@nongnu.org; Fri, 09 Aug 2024 05:00:33 -0400 Received: by mail-wr1-x42d.google.com with SMTP id ffacd0b85a97d-3687fd09251so947562f8f.0 for ; Fri, 09 Aug 2024 02:00:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1723194027; x=1723798827; darn=nongnu.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=NmYyzHtVTcDjPEdEVArsEoK0VXoPUGExEsdo4wzUW1I=; b=iJj0nN9ILoM4E15+rR+QD6kmnyzoGrFq/rSLLQDO+ffquvH/qbwtxsXP+vxPv4Dq1w QpR7VOGoirtssSqs1GipagOKLXno5DeICPhY5mq5w//PHflMd8hS3OlM9usPsrgcIOBE aPAXOpVQBm4aJCgPfsJTfCyNpV4uOUyB5nIoTZCIPLQp8N0oQ+SeJehnSu0nxbRWC+5h mX00/1kbk6NycAOzj7pU9UdHFd0ip1r6noRsLQgpV1Tz+v7btuOaaKdFTUFfP+EtH9+2 GQY07ye4szuZzPgC+xT06+mz4anZQkqa4BztinT5SKiO8AwII6tU7Mwcxj3OK1RCr2vB 5xMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723194027; x=1723798827; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=NmYyzHtVTcDjPEdEVArsEoK0VXoPUGExEsdo4wzUW1I=; b=uWwIL3XMuG2uVjEIBYS/uHlX43pmakJ9T4U/a53k/IQtmszjYkrqiqEWLX1MY7WhLU oTaYh3WhZ7x/8iHeOZFK/+qc2G9s+92TP9TVlQP88qWus//GE+7KDz2O9Ic9q1DxifSu wNZwe88+hOrhdNndL36Yki91eP7ERw7kG5XLI64oSkDN8yGnQ/VSd/uZ+YhLi5Anl2Lf y2diCgWnypnmdT2jEDYPaJIcZYXngc/sM2semleIxlrwhHPBRW6FQqIt8tApCjyCvG5L JxRu96QUyi9fSQFfgM8hN4NPzUPvwrQUaJFRggbKDjakH6ERt7FjiAnKHSSF21ow+lv6 nKiw== X-Forwarded-Encrypted: i=1; AJvYcCWKp/ova53A+OtmElfms7RDUZlUrG64c4Nb6kYqJ3pkVpcbjzfW56aBmKLdKYIb4Jpx59+Y5CK4BdoU2ub26XGC4yQ34zU= X-Gm-Message-State: AOJu0YzR3Jzy7Rm2lcG07KYE+PNGuOpKuDLQ5GQCW9PklySJqOE7LDPb 19B4p90FhPbTykiLeHcb5M2EJx/EdbiDUFoklBNeMDHkp31+OGES+WW6tKNYWfYPB6FiqQdpuTq r+9ncMJ018sf26ALol2Sn0l+5+NXuHA1OjL4VCw== X-Google-Smtp-Source: AGHT+IHASa5CI/8VmF2a8okXHufY3PkBARhBp95qEtdhDbCsWAHqeSitT533Wpul/4/9NgM/SMffObYY+EtStWUPA0Q= X-Received: by 2002:adf:cc88:0:b0:368:4edc:611e with SMTP id ffacd0b85a97d-36d5e7fd9e1mr676747f8f.14.1723194027412; Fri, 09 Aug 2024 02:00:27 -0700 (PDT) MIME-Version: 1.0 References: <20240809035134.699830-1-gshan@redhat.com> <20240809035134.699830-4-gshan@redhat.com> In-Reply-To: <20240809035134.699830-4-gshan@redhat.com> From: Peter Maydell Date: Fri, 9 Aug 2024 09:59:52 +0100 Message-ID: Subject: Re: [PATCH 3/4] hw/arm/virt: Use kvm_arch_get_default_type() To: Gavin Shan Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org, pbonzini@redhat.com, philmd@linaro.org, richard.henderson@linaro.org, shan.gavin@gmail.com Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::42d; envelope-from=peter.maydell@linaro.org; helo=mail-wr1-x42d.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=unavailable 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 Fri, 9 Aug 2024 at 04:52, Gavin Shan wrote: > > kvm_arch_get_default_type() and kvm_arm_get_max_vm_ipa_size() are > interchangeable since the type is equivalent to IPA size (bits) > with one exception that IPA size (bits) is 40 when the type is zero. Well, sort of, but they're conceptually different. kvm_arch_get_default_type() is the API for "give me the value I need to pass to kvm_ioctl(s, KVM_CREATE_VM, type)"; it's architecture independent and different architectures do different things. In the future Arm might need to do something other than "just pass in the IPA size". kvm_arm_get_max_vm_ipa_size() does exactly what it says on the tin: it is an Arm specific function that returns the maximum supported IPA size. I would prefer not to conflate the two. thanks -- PMM