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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D842CC433EF for ; Mon, 20 Dec 2021 09:07:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230112AbhLTJHB (ORCPT ); Mon, 20 Dec 2021 04:07:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229474AbhLTJG7 (ORCPT ); Mon, 20 Dec 2021 04:06:59 -0500 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 199E4C061574; Mon, 20 Dec 2021 01:06:59 -0800 (PST) Received: by mail-ed1-x534.google.com with SMTP id x15so35527244edv.1; Mon, 20 Dec 2021 01:06:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=7rGLuctH17X86MIT1q+VjDiELEpLEz54V+ybICfliCY=; b=F1QKF6JdEydW7dva1Vc3CloUwYkLRRuBBi1rFQoQkey9y87fWPDjY7jyKdd8q7N1yy Z1rOXCgDYVFDwRpGHhfvbQQeij0lzofm5YBTOMAYqPl3/1kz0/+s7oLg15nh7Xguo6SO pqvM9a3VZNXjGoOTOTI3LjjRF/5zq2mmgCioYBNOPkHGrB+gCKk3Nq3t1sT3TqNFSfPc BTclqTcKrqeQIsn7WjxZ2t4l/rJF3o0wxtdW8Ixm8dLvujyr0xDh8Ht3+FUqEXqSscYp 4Cdaks5LweoPuZFUxHrKgrLou9zgLGiRV25ey5RbBv/UcGMnqS8/8kgPsjrNmiyyvDWF YlHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=7rGLuctH17X86MIT1q+VjDiELEpLEz54V+ybICfliCY=; b=LK8lNXfU+EFZWURHiuMadvF7HXjbXjoSGqNyBkSdYfokl7bwe7FEACkB022zoCS3Qi fCQs49tQuTmByBATHN8Bhaq16RpTlhG008tgrca2LpygFSQ5uh3v5EXGA936zl/EHGDj IGFUovZjmuIAJJn4HAxe5DxXEntazFGk3SBQrvt6aYI49rVpg3KD47T0WIagoF2foHN+ hweywDPBjdVWL2XUZFi+yWBhL90LhFgPFB84cUp/kce8wKS3ykmxMf941dd8QKAuOlTt uMgpFO3wl225Aq82a06Jkvuo+P/Sb4RCO4xEBVnKXLnb1jeCuRQXzgLtztPLRl7oMkYU PosQ== X-Gm-Message-State: AOAM533RYCVXfTGBs+CpblgmB0trXcW3gdaeZoPeErgRunlQ1fSEINgl mtfNKG8rueA+5ACAGXqivbw= X-Google-Smtp-Source: ABdhPJxc4+56LGUN6NrNDOuFE0g4DQGtvm2CHJtn9p7lYvB0aYj1Nve5TSxIftjZ3OV/mVNPsJk7Ig== X-Received: by 2002:a05:6402:2747:: with SMTP id z7mr3774719edd.321.1639991217578; Mon, 20 Dec 2021 01:06:57 -0800 (PST) Received: from [192.168.10.118] ([93.56.160.36]) by smtp.googlemail.com with ESMTPSA id n12sm4009071edb.86.2021.12.20.01.06.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Dec 2021 01:06:57 -0800 (PST) Sender: Paolo Bonzini Message-ID: <3ffa47eb-3555-5925-1c55-f89a07ceb4bc@redhat.com> Date: Mon, 20 Dec 2021 10:04:14 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v2 18/23] kvm: x86: Get/set expanded xstate buffer Content-Language: en-US To: Jing Liu , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com Cc: seanjc@google.com, jun.nakajima@intel.com, kevin.tian@intel.com, jing2.liu@linux.intel.com, guang.zeng@intel.com, wei.w.wang@intel.com, yang.zhong@intel.com References: <20211217153003.1719189-1-jing2.liu@intel.com> <20211217153003.1719189-19-jing2.liu@intel.com> From: Paolo Bonzini In-Reply-To: <20211217153003.1719189-19-jing2.liu@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/17/21 16:29, Jing Liu wrote: > +/* for KVM_CAP_XSAVE and KVM_CAP_XSAVE2 */ > struct kvm_xsave { > + /* > + * KVM_GET_XSAVE only uses the first 4096 bytes. > + * > + * KVM_GET_XSAVE2 must have the size match what is returned by > + * KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2). > + * > + * KVM_SET_XSAVE uses the extra field if guest_fpu::fpstate::size > + * exceeds 4096 bytes. KVM_GET_XSAVE2 and KVM_SET_XSAVE respectively write and read as many bytes as are returned by KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2), when invoked on the vm file descriptor. Currently, KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2) will only return a value that is greater than 4096 bytes if any dynamic features have been enabled with ``arch_prctl()``; this however may change in the future. The offsets of the state save areas in struct kvm_xsave follow the contents of CPUID leaf 0xD on the host. Paolo