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 X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C232DC433E9 for ; Fri, 15 Jan 2021 13:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9990923877 for ; Fri, 15 Jan 2021 13:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731611AbhAONvu (ORCPT ); Fri, 15 Jan 2021 08:51:50 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56847 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731264AbhAONvt (ORCPT ); Fri, 15 Jan 2021 08:51:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610718623; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GClJQCWfDVIp8Abu+51pXYFvR3+SULW6nqe1Zw2Nhco=; b=F+C/Hx6rDj6qxuWxoXF4UDZORvoqvomimmfQoOsHcoZKMBYGVHBSLExAifxSGlvAaOJJBl 9+lkUfyfYCNzsEn9TAbCqWGD+UhdB/3cSdgIoQMafk/NPnL9D8VPYFjPIgzaRRq34Bhjnb 4p+LlPZHWepEE14XN/D+inHv6mlglS0= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-429-iEYQ6LsKNcq697ZzCYafEA-1; Fri, 15 Jan 2021 08:50:21 -0500 X-MC-Unique: iEYQ6LsKNcq697ZzCYafEA-1 Received: by mail-ej1-f71.google.com with SMTP id p1so3601063ejo.4 for ; Fri, 15 Jan 2021 05:50:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=GClJQCWfDVIp8Abu+51pXYFvR3+SULW6nqe1Zw2Nhco=; b=Ro6dLC33RPrUrbLgXyKjSmazJbsW2yEJBt8V9hVEFQsa0GjB5F46O9PJiJBME/mSW/ stpPZsBhgN0/d8meBcKd9a0PGd1+XZqyKi6za0hvOXo1bTYuQEcOBaze5aRzJUQIPugD qum6gp0L23c82+gfbrmgbf4ll7QlC8aO75CWq+k00k1Y8xTk22GxhlY1uiGysSpCm+/x Dw6Q0RtpIY20BxzslQLS0nN71+8Hr0atVjcELCyJXDz3I0wpM0EECE+Hao6xqq55XYXt 4ltmWQAJtP54h6w5ergaKwaeeAkQ64u7AmwhezPjT/+O6Ovwl0WEl45JXiJRHvzOMUB+ b1cQ== X-Gm-Message-State: AOAM532ZIB0c1Rivr5mE2VVDxryYORcJuVKQEhrd1tjN+5epsOcuRtZe 1q4qbAPtjk9now0h7G+CRL+stPCKoyiJ8oWATyFivuQv3oKwkLokevRgjeSfkT28MKoJ/9bNV4O DLAgxHL/9Ro1W X-Received: by 2002:a17:907:3f13:: with SMTP id hq19mr9060269ejc.142.1610718620211; Fri, 15 Jan 2021 05:50:20 -0800 (PST) X-Google-Smtp-Source: ABdhPJxKpmIkaYyI1N+J5ZOU1XodqPeFuoNmwqs4aW3Sw/NgHl/VK+y6PQ/FPUfmzNJDpLKJ7aNWYg== X-Received: by 2002:a17:907:3f13:: with SMTP id hq19mr9060257ejc.142.1610718620074; Fri, 15 Jan 2021 05:50:20 -0800 (PST) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id u2sm3461214ejb.65.2021.01.15.05.50.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 Jan 2021 05:50:19 -0800 (PST) Subject: Re: [PATCH v2 2/3] KVM: x86: introduce definitions to support static calls for kvm_x86_ops To: Peter Zijlstra , Jason Baron Cc: seanjc@google.com, kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andrea Arcangeli References: From: Paolo Bonzini Message-ID: <84b2f5ba-1a16-cb01-646c-37e25d659650@redhat.com> Date: Fri, 15 Jan 2021 14:50:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 15/01/21 10:26, Peter Zijlstra wrote: >> +#define KVM_X86_OP(func) \ >> + DEFINE_STATIC_CALL_NULL(kvm_x86_##func, \ >> + *(((struct kvm_x86_ops *)0)->func)); >> +#define KVM_X86_OP_NULL KVM_X86_OP >> +#include >> +EXPORT_STATIC_CALL_GPL(kvm_x86_get_cs_db_l_bits); >> +EXPORT_STATIC_CALL_GPL(kvm_x86_cache_reg); >> +EXPORT_STATIC_CALL_GPL(kvm_x86_tlb_flush_current); > Would something like: > > https://lkml.kernel.org/r/20201110103909.GD2594@hirez.programming.kicks-ass.net > > Be useful? That way modules can call the static_call() but not change > it. > Maybe not in these cases, but in general there may be cases where we later want to change the static_call (for example replacing jump labels with static_calls). Paolo