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 37D46C433EF for ; Tue, 30 Nov 2021 11:29:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238480AbhK3Lc7 (ORCPT ); Tue, 30 Nov 2021 06:32:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232569AbhK3Lc6 (ORCPT ); Tue, 30 Nov 2021 06:32:58 -0500 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E43B7C061574; Tue, 30 Nov 2021 03:29:38 -0800 (PST) Received: by mail-ed1-x535.google.com with SMTP id g14so85339322edb.8; Tue, 30 Nov 2021 03:29:38 -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=4ZJYK5Pyg6M1OZI8R6OhktHvKj8jONfwxsgyqS7zKVw=; b=hS3xdsuhLh825Zy5CyXqy8kdkjallgGS9ThnPKsUscIhTlNXuE6CejEfZljPIGaRuS oc7ADJYJNccl+iIS+fb435+kT+Wo5w123ioG7scg6MMSsuz6aHhDoNbNX8jXCces5K0F PYjM4g+cfZ2gNNcIqQh/s9hcryBHhQBsIb49ziFJEAIx5EXi74/YY3XfzUiXOe18ECIo bu7Egs9Ck/npOx62zHI52FWVmY9ihQKPeevV9cXirPD/e+LgPMqRaWL+kLq51qPSTFOA wxTvZBWNXewy9P/5UDCdMpWexvKVyhoS29YHyJi/92EVrkOB80KkptXB1ZoBj2CZavVE mxxw== 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=4ZJYK5Pyg6M1OZI8R6OhktHvKj8jONfwxsgyqS7zKVw=; b=xTONBY5nwMsWrvwhuPxG8aLxc3FSYm2OaE8PyJvsqykWjePuvE8jp6ciD9lPpU3aiQ ktCYGCV3VEYJgdZmaJESegJxGTOY2oE0ZmBS79h+cLuh2U/66enfMu/sNQd3I3AwI/Gc Tv1L5mIh//PCvNh3rXFO7C7WCUn7+2G9moTRJDKFeM8yNT234t+t22uoBULuxWbfHdK5 dqHLLEOoFiGaT7YxG6uqszGYUhRzwV2XUXVK56+YiamjB+t5J6Rnd38TeXo5B0FLlAd1 MhYG6l0M2Zo2ASDlTxm+bYIsheQnZsj+4yYsOcV4bQHn7VxUm1RL4B57X1aSJ6PgpQ65 UxhA== X-Gm-Message-State: AOAM531141JdUtFgWB3UjEkvtasMeemuo+Rs/A2bisbehlWHxaiY0Opy M2TmF/BveIXzMAb65wHZLPGm/kGbDT4= X-Google-Smtp-Source: ABdhPJxWSSekJtGQrdd4lB7tQwJ9KjEr5N4mPYhMxXVyQrmrgXJrf5XZQFVeleF2doedUDkfSYSvQQ== X-Received: by 2002:a17:906:1697:: with SMTP id s23mr68766522ejd.60.1638271777525; Tue, 30 Nov 2021 03:29:37 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.googlemail.com with ESMTPSA id he14sm8981167ejc.55.2021.11.30.03.29.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 Nov 2021 03:29:37 -0800 (PST) Sender: Paolo Bonzini Message-ID: Date: Tue, 30 Nov 2021 12:29:36 +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 27/28] KVM: x86/mmu: Do remote TLB flush before dropping RCU in TDP MMU resched Content-Language: en-US To: Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Hou Wenlong , Ben Gardon References: <20211120045046.3940942-1-seanjc@google.com> <20211120045046.3940942-28-seanjc@google.com> From: Paolo Bonzini In-Reply-To: <20211120045046.3940942-28-seanjc@google.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 11/20/21 05:50, Sean Christopherson wrote: > if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { > - rcu_read_unlock(); > - > if (flush) > kvm_flush_remote_tlbs(kvm); > > + rcu_read_unlock(); > + Couldn't this sleep in kvm_make_all_cpus_request, whilst in an RCU read-side critical section? Paolo