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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6A6B1C369B2 for ; Mon, 14 Apr 2025 10:57:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u4HV3-0003vB-Cc; Mon, 14 Apr 2025 06:57:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u4HUy-0003uF-JY for qemu-devel@nongnu.org; Mon, 14 Apr 2025 06:57:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u4HUx-0008Nv-5r for qemu-devel@nongnu.org; Mon, 14 Apr 2025 06:57:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744628225; 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:autocrypt:autocrypt; bh=AU/6w6Mt/TK/rtTsO+4KvA3bUXlqruFH2A0OZ7uhg1s=; b=bumz265GMWV/FmDx4Ex8qG66JFtejgr0jofHb8W9kjjhHMvXYdrPI90bhv7/gx3X4Wx19M d7d81FI6On7u8JS2GRdc19c9b/fgCTdh7zo/l7abohybdgcKq2a+8m9e6MfDJty12kA9r+ 9IUrs6QUGQFONTQHpgIaiWffXQDxdio= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-142-AnXymfr4NxCZWlg8iV1D9A-1; Mon, 14 Apr 2025 06:57:04 -0400 X-MC-Unique: AnXymfr4NxCZWlg8iV1D9A-1 X-Mimecast-MFC-AGG-ID: AnXymfr4NxCZWlg8iV1D9A_1744628223 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-39c30f26e31so2820642f8f.3 for ; Mon, 14 Apr 2025 03:57:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744628223; x=1745233023; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=AU/6w6Mt/TK/rtTsO+4KvA3bUXlqruFH2A0OZ7uhg1s=; b=dB4/p9HyvrlHlActThwtQ89Fhqe2pg1vk6cpaNz1++mV/yyX0oWNIPpVcZERPCHbWt aQtg72pqHOouxEH8D6KCgd/Yuh4tBPeWEwjM3t0mAElkOp4LlQBBtSAzkgCB3han6RSC fH5wVH1T+OJxnpIReZaSnRjne7euDWBUXpP+nBfrSv5ixPG6OfEK+IS7mnkO0J+gQLG0 NekdSEZTH9nahpZpX4jL+zejokyYhQdKnJAc7qV8OAPjILH++KDCro35liAU0PLr0Ock b2nbnYqN30PoP5P1RF8fbssNMeGDiMrN+ia/XeQwqI518g0YYEhK9tZ+nnv0cOodjcNg y4LA== X-Forwarded-Encrypted: i=1; AJvYcCWUt11L2RKPzIACKG45/prfAv5iXSx5aSBNDV6YRjJw0hjwABzcuqKSKIC8Jq5SMMTWZxieBX6OVfDM@nongnu.org X-Gm-Message-State: AOJu0YwGHgAVnQZ/ZWTONB3XaAN9WeIH9oLfXjF9qWlrL70WFRoj7JWV YbGapECLtQkGSiAIvbm/uZj+U6lxAXSPjI/KMWBP02kwxSvrqNrDFfPA5jnXm+bFSS1JoWIBoJE z2laCCOpmR+IulABZeu5q2wWM/rZI/zTFATGpmx6GGVs8NUgkQapf X-Gm-Gg: ASbGncvA1cUV7be5aLIMfGnEQCYFxxB3IJU9XA14wM/SfxYI+VvRwVcnriIDCWcyNkZ bSNTcnFqDy7DmX4GPPovS/SLYKcrf9nlBg5f6c2lTtE6Y3UENpXjulboDbkmabdWuLSk7HcV2Vb TQjLhQ9Qfa1gdFa+D8yysoNGpJgmu/xIwR3Yb9iA2baSDk5BQI6gAxtKbBiPNb1v27ylGMzxG7T aZSszSQHLs2gBUz/D/wtQjPUo1w1t906a75aurFSiWuFw5tg0UDyPCfUlub71BbuxR5WON+j+KO GVzVJJZwky2AFao+ X-Received: by 2002:a05:6000:2401:b0:391:212:459a with SMTP id ffacd0b85a97d-39ea521207fmr8616627f8f.22.1744628222855; Mon, 14 Apr 2025 03:57:02 -0700 (PDT) X-Google-Smtp-Source: AGHT+IG6GzRnbYHfsHjcYOVRGfR4i1sVbF1U8JrYq3DmXWXtf7sYpXMq3Kv+uuz1TD7o2eDncPJwTQ== X-Received: by 2002:a05:6000:2401:b0:391:212:459a with SMTP id ffacd0b85a97d-39ea521207fmr8616607f8f.22.1744628222432; Mon, 14 Apr 2025 03:57:02 -0700 (PDT) Received: from [192.168.10.48] ([176.206.109.83]) by smtp.googlemail.com with ESMTPSA id ffacd0b85a97d-39eae96c6b8sm10730213f8f.37.2025.04.14.03.57.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Apr 2025 03:57:01 -0700 (PDT) Message-ID: <4838b44b-49db-4f47-96da-52b9504b4f67@redhat.com> Date: Mon, 14 Apr 2025 12:57:00 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] system/main: transfer replay mutex ownership from main thread to main loop thread To: Pierrick Bouvier , Nicholas Piggin , qemu-devel@nongnu.org Cc: philmd@linaro.org, Stefan Hajnoczi , =?UTF-8?Q?Alex_Benn=C3=A9e?= , Phil Dennis-Jordan References: <20250410225550.46807-1-pierrick.bouvier@linaro.org> <20250410225550.46807-2-pierrick.bouvier@linaro.org> <7e760e04-0571-48f3-9aa7-e71c631dcaff@linaro.org> From: Paolo Bonzini Content-Language: en-US Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: <7e760e04-0571-48f3-9aa7-e71c631dcaff@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 4/12/25 19:24, Pierrick Bouvier wrote: > On 4/11/25 22:30, Nicholas Piggin wrote: >> Do we actually need to hold replay mutex (or even bql) over qemu_init()? >> Both should get dropped before we return here. But as a simple fix, I >> guess this is okay. > > For the bql, I don't know the exact reason. In general it's better to assume that there can be other threads (and therefore you need BQL). Also, Rust code panics if you access a BqlCell or BqlRefCell without holding the lock. Paolo