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 AE57DC32774 for ; Tue, 23 Aug 2022 08:17:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242447AbiHWIRp (ORCPT ); Tue, 23 Aug 2022 04:17:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242510AbiHWIL1 (ORCPT ); Tue, 23 Aug 2022 04:11:27 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 541D6E033; Tue, 23 Aug 2022 01:08:34 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id x14-20020a17090a8a8e00b001fb61a71d99so1296657pjn.2; Tue, 23 Aug 2022 01:08:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=rxqK6Y9ADvrz5Qb+wgm4oP/mkFK1hFUakcQeyZkdrjg=; b=qa9kpU15MBZeI3ijyNK+ezq/HuCWZTPrm8SqDeM3OhmYMHlEIsxRQ81auUqgXa5sMk mSPVHEtY8NIBKqYxWij27UCrey7fmy2dFAi7PCbv6LG20nhoh4hOfa3Vh7qnxMl3d0TG FSEn47px272RJY08U2c2gnFCw7LVrAgwXRx5nhKPyAZuOmTZNSM/bCbOrF+x39b1MqXP eEk7ISR6NhbQn/pxqsF8GF1G2PpJITJN+NaU6ZDIqxQ/+akfKBs/DuJY7WKXIy1g2Gj+ JXM2c51DUHfA1hF2pbaDkXRldSoM2MjQ34wC6vcskU22oS5edk4m2hxXuNcL8EaSSrRX 9SCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=rxqK6Y9ADvrz5Qb+wgm4oP/mkFK1hFUakcQeyZkdrjg=; b=kWodTwXudlVoVx6hSRkoM2gJtMKZwz8vTFw8y2MDXm+jeGZe7++045RgIOX9DiEd55 xatckscbLVC1Ysh0Lj52IQIT6FDuPZZeFtJmJHJVaIpEFEXOe4wYuA2D2Xcz1QwHSNEZ 07BJKHwMSUB2u8Wb04TdeW+39wburX8xOUtHS2c/z90L9bTdyrj3qiL4Z95DOc3DfZsz bImRs+SHGjZVA5Mv2Ns8NHBrKOxCK4gdXePKQzhpwUZWnN3cDyPOYwk4P3/kknoy6cow wcOBcXpoeo7PU0O6eRYHWbJPNKBrvleQbwj3Ed2+PDuLoByzUCKoEKJR+9SUG5VGOwXb TlKw== X-Gm-Message-State: ACgBeo1KLxawv+7bWy9yAeIpm506aJnFiE/bANdzGg1rZH1LxlBYrzcl KJVcskYLlVq8z//BYaxXKhk= X-Google-Smtp-Source: AA6agR6N4egFU92pUmyxhcXqsOyU+Q8ywulCC4ChqVABz3U2dM4ePorwqXZKy7WP8jur17QK6kVrAw== X-Received: by 2002:a17:90a:e7c2:b0:1f4:feeb:20ee with SMTP id kb2-20020a17090ae7c200b001f4feeb20eemr2200781pjb.114.1661242113171; Tue, 23 Aug 2022 01:08:33 -0700 (PDT) Received: from localhost ([192.55.55.51]) by smtp.gmail.com with ESMTPSA id p127-20020a625b85000000b00536bbfa4963sm3012743pfb.139.2022.08.23.01.08.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Aug 2022 01:08:32 -0700 (PDT) Date: Tue, 23 Aug 2022 01:08:31 -0700 From: Isaku Yamahata To: Chao Gao Cc: isaku.yamahata@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, isaku.yamahata@gmail.com, Paolo Bonzini , Sean Christopherson , Kai Huang , Will Deacon Subject: Re: [RFC PATCH 12/18] KVM: Do processor compatibility check on cpu online and resume Message-ID: <20220823080831.GE2147148@ls.amr.corp.intel.com> References: <60f9ec74499c673c474e9d909c2f3176bc6711c3.1660974106.git.isaku.yamahata@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 23, 2022 at 03:50:09PM +0800, Chao Gao wrote: > >diff --git a/virt/kvm/kvm_arch.c b/virt/kvm/kvm_arch.c > >index 2ed8de0591c9..20971f43df95 100644 > >--- a/virt/kvm/kvm_arch.c > >+++ b/virt/kvm/kvm_arch.c > >@@ -99,9 +99,15 @@ __weak int kvm_arch_del_vm(int usage_count) > > > > __weak int kvm_arch_online_cpu(unsigned int cpu, int usage_count) > > { > >- if (usage_count) > >- return __hardware_enable(); > >- return 0; > >+ int r; > >+ > >+ if (!usage_count) > >+ return 0; > >+ > >+ r = kvm_arch_check_processor_compat(); > >+ if (r) > >+ return r; > > I think kvm_arch_check_processor_compat() should be called even when > usage_count is 0. Otherwise, compatibility checks may be missing on some > CPUs if no VM is running when those CPUs becomes online. Oh, right. Compatibility check should be done unconditionally. -- Isaku Yamahata