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 55C2BC6FA82 for ; Sun, 11 Sep 2022 02:51:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229727AbiIKCvA (ORCPT ); Sat, 10 Sep 2022 22:51:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229589AbiIKCu7 (ORCPT ); Sat, 10 Sep 2022 22:50:59 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 556F331DC1; Sat, 10 Sep 2022 19:50:58 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id f24so5419230plr.1; Sat, 10 Sep 2022 19:50:58 -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:subject:date; bh=WOfUBmdbsodFIdF1n3FF4SIyEmSqFy1s8LSqImxsRWM=; b=nlJtZSZEhPJWcaLLK1L8Z+VRzHUljkNLpYXD8KRtpuPPQ6iRxm2HACBdcyt7Aq6Fkb spK6H68e/roRUpgBsjulj2U5gDlC9QluMRDO4q6bx7kM2fVuIIpKGzaAfEiWpn1E+Fkw XJxzkucYJW3BIxuhnxgcwxswjdInlc8/i2qgVkwK2CDyuQgu2GKFnI7LVm0jVdyXikzV h4gp8GuM8Q8sj2GWGpL1YNX5zgZAL1B5HbkfCLF5Y+4ZnVrCRbTV3zm3Geg9Q5f1l10b 2ornV0vei5t7/vbo2yqi9BK3EfdB2EoGSflNhNFXEcm0M2SzFaZOSXX+lOhClV4hal6/ Kvcw== 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:subject:date; bh=WOfUBmdbsodFIdF1n3FF4SIyEmSqFy1s8LSqImxsRWM=; b=lqL5Nn87K4+ZhmWxVzH58zJ5tWeTgHk1b6L0m4w8gS8Yj4Ncm1IITfSMeVQjsGGond gVsYSwxkT0vXDI43hxmlUnH64RgctUlsK0SwZi/cSjWK+BDNMXlVGC+I1/OwpAvXZEjz nudkvmp34lJmWWfbjfeR3lOy1r0jK1rGrL0f+TdTGEdG8nN8kwfIWSzBBwkk98gFHMRD lmwOon844YHRL8HAlVaBjFwUBlSeEH8XNdgihVHdSYZ6WnCd5knTmpSsGXP37vKZw6xm wNHHs1URuUkDsRqp5qC6yeNZoKKhMnkZdZHan81l9U9U9XbpZyeqblSYxyIaxHfAVUW3 0kSg== X-Gm-Message-State: ACgBeo1QuU8vuP0ZP7R+tpMyUoLAmKNRq46YIkMfCSpZPalb3FeAhKw+ ePVhOSHYJ0ZKyr/F4cezYoU= X-Google-Smtp-Source: AA6agR6E781URqVLZUSymEJO/4uB5VIkLpGehxnXgU9n+4dqZMrwK1j7/AMV3riCoURT0xk5HLJqqA== X-Received: by 2002:a17:90a:9295:b0:202:582b:1765 with SMTP id n21-20020a17090a929500b00202582b1765mr16777561pjo.99.1662864657781; Sat, 10 Sep 2022 19:50:57 -0700 (PDT) Received: from localhost ([192.55.55.56]) by smtp.gmail.com with ESMTPSA id x5-20020a628605000000b00540d75197f2sm2493486pfd.143.2022.09.10.19.50.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 10 Sep 2022 19:50:57 -0700 (PDT) Date: Sat, 10 Sep 2022 19:50:56 -0700 From: Isaku Yamahata To: Chao Gao Cc: isaku.yamahata@intel.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Bonzini , Sean Christopherson , Marc Zyngier , Will Deacon , Yuan Yao , isaku.yamahata@gmail.com, Kai Huang , Atish Patra , Shaokun Zhang , Qi Liu , John Garry , Daniel Lezcano , Huang Ying , Huacai Chen Subject: Re: [PATCH v4 13/26] KVM: Add arch hook when VM is added/deleted Message-ID: <20220911025056.GA873583@ls.amr.corp.intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Sep 09, 2022 at 02:08:04PM +0800, Chao Gao wrote: > >+static void kvm_del_vm(void) > >+{ > >+ cpus_read_lock(); > >+ mutex_lock(&kvm_lock); > >+ kvm_arch_del_vm(kvm_usage_count); > >+ mutex_unlock(&kvm_lock); > >+ cpus_read_unlock(); > > kvm_arch_del_vm() is an empty function now. I don't understand why > cpus_read_lock() is needed. Maybe add the lock when you fill up > kvm_arch_del_vm(). The next patch populates it with on_each_cpu(hardware_disable_nolock, NULL, 1); I will move adding lock to the next one. Or revise how adding arch hooks and populating part. -- Isaku Yamahata