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 058D1C5AD49 for ; Mon, 26 May 2025 12:10:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uJWdY-00066y-8A; Mon, 26 May 2025 08:09:00 -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 1uJWdR-00066Z-Qd for qemu-devel@nongnu.org; Mon, 26 May 2025 08:08:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uJWdP-0007RC-CV for qemu-devel@nongnu.org; Mon, 26 May 2025 08:08:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748261326; 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=Glx3ZE+aEUbK3b+fSAb6UJf7TDKVLgLAXxwK4aNQMnw=; b=YXJkX+EX/HLRlGG3rbHlVkRcDnze2FjdG4NXQmUX5Y5lCRC5xqfjh6dVmtIs4r86Zrv3bT +e9Ma3aAFntphAgNYnQTX/LAZs6+mYrD6jGzXn+bfuE1ncfAz9vM7hJ6KcXIiHiJq60Rz/ G8qY4jgWdVjIVrrLbN1WeldeRV7jrqg= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-349-MdZqG1x2PqWFC9H5nJNNCg-1; Mon, 26 May 2025 08:08:44 -0400 X-MC-Unique: MdZqG1x2PqWFC9H5nJNNCg-1 X-Mimecast-MFC-AGG-ID: MdZqG1x2PqWFC9H5nJNNCg_1748261324 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-441c96c1977so12547205e9.0 for ; Mon, 26 May 2025 05:08:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748261323; x=1748866123; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language: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=Glx3ZE+aEUbK3b+fSAb6UJf7TDKVLgLAXxwK4aNQMnw=; b=sr74YenzoJM8JpD+069QqeO/WE5t37ekcA/iOY4+81k4F0EzfWir6Xdx+kQ4BaoqMY NB9wFUbA/9qfvHKizLBQ9OB2oZcBldtNnj8Qxd7Y0OluYMOF1bjLuf481WlMUUN5Olbk Ujsznb4okbfgAx/kuG4nOVCP803tHCfzgHEn22Npo8XZ+VMiaEEwmizwKEMeOlqL0BfA 9EqBVaLn7zNAWHIFhHohdtx0AS5rnzEdY0aZtZgtFyY9vIEs0Jg5NQnQ3xVllUXBUR+t MtKc6/lTcx2N4pixWx8X3R1Z+RiLVzFeA9X1DtI6NOjmt3fpu4c/JP7xClaZkPkYxHsr c21A== X-Gm-Message-State: AOJu0YwB9J0z0cAFOZW3S+w8SWTKImhBQnFp4cJ7u4YNl8cMolcPTlPQ g2aoONhinkOSU+ReP0Q1sK4dHAepKlIkLGr2At7yp8lqMjPlwMkZHAmxJDB6+TFv+1q+0dyy88v gGBilNDiFPOQVxHqnQBBgSdHkK7RB+Vw/5sLEv/OEfI6abC+HrnbzRROK X-Gm-Gg: ASbGncutq2NSija1Cbxpb9msHcjUC5of/a3ISVx84ox9zKwsH2wrynXSBQezgPeOnde gYYiFf9OQy/xqbLsQ5zJtL5CRhqrGot7kUhOV3RXdG/XgMhlyUp0HQHBQMqmPVEBVVQEgfAzV30 qcC8W0XZGOCu+Q8IWXdw5jI3hrFV6pzdGt09jBYmf/rc9oLNZnycTSg+9hwcMp9BBpx43Patx5P owdH6kx5Goa2KKEWGpXTqHJPeBBw8WtaV0U8PI6SVEFpkVgpkpiK2MQ8RDbr6JYuAkFA1x9IaZS Lwqajfs2M/A/SWa4vMvcQYfVncdWkcBn/45iSBr/dk/3Jick0A== X-Received: by 2002:a05:600c:3ca6:b0:44a:b478:1387 with SMTP id 5b1f17b1804b1-44c9465c97cmr79822505e9.17.1748261323675; Mon, 26 May 2025 05:08:43 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHHkDDaluNpXERncpMYCGszXtZM2cTaqlLKvjdbGEjx6smyvkTBY8ewkQECNK/MxvdYuFayxA== X-Received: by 2002:a05:600c:3ca6:b0:44a:b478:1387 with SMTP id 5b1f17b1804b1-44c9465c97cmr79822045e9.17.1748261323212; Mon, 26 May 2025 05:08:43 -0700 (PDT) Received: from ?IPV6:2a01:e0a:280:24f0:3f78:514a:4f03:fdc0? ([2a01:e0a:280:24f0:3f78:514a:4f03:fdc0]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-447f3dd99edsm233207885e9.36.2025.05.26.05.08.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 26 May 2025 05:08:42 -0700 (PDT) Message-ID: <28e57f32-a7f7-4bb8-af6e-483e72750c0d@redhat.com> Date: Mon, 26 May 2025 14:08:41 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 07/29] vfio: add per-region fd support To: John Levon Cc: qemu-devel@nongnu.org, Alex Williamson , Paolo Bonzini , =?UTF-8?Q?Marc-Andr=C3=A9_Lureau?= , Peter Xu , David Hildenbrand , Stefano Garzarella , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , "Michael S. Tsirkin" , Thanos Makatos References: <20250520150419.2172078-1-john.levon@nutanix.com> <20250520150419.2172078-8-john.levon@nutanix.com> <340d64a0-b85c-422a-ac81-4de6b10c8228@redhat.com> Content-Language: en-US, fr From: =?UTF-8?Q?C=C3=A9dric_Le_Goater?= Autocrypt: addr=clg@redhat.com; keydata= xsFNBFu8o3UBEADP+oJVJaWm5vzZa/iLgpBAuzxSmNYhURZH+guITvSySk30YWfLYGBWQgeo 8NzNXBY3cH7JX3/a0jzmhDc0U61qFxVgrPqs1PQOjp7yRSFuDAnjtRqNvWkvlnRWLFq4+U5t yzYe4SFMjFb6Oc0xkQmaK2flmiJNnnxPttYwKBPd98WfXMmjwAv7QfwW+OL3VlTPADgzkcqj 53bfZ4VblAQrq6Ctbtu7JuUGAxSIL3XqeQlAwwLTfFGrmpY7MroE7n9Rl+hy/kuIrb/TO8n0 ZxYXvvhT7OmRKvbYuc5Jze6o7op/bJHlufY+AquYQ4dPxjPPVUT/DLiUYJ3oVBWFYNbzfOrV RxEwNuRbycttMiZWxgflsQoHF06q/2l4ttS3zsV4TDZudMq0TbCH/uJFPFsbHUN91qwwaN/+ gy1j7o6aWMz+Ib3O9dK2M/j/O/Ube95mdCqN4N/uSnDlca3YDEWrV9jO1mUS/ndOkjxa34ia 70FjwiSQAsyIwqbRO3CGmiOJqDa9qNvd2TJgAaS2WCw/TlBALjVQ7AyoPEoBPj31K74Wc4GS Rm+FSch32ei61yFu6ACdZ12i5Edt+To+hkElzjt6db/UgRUeKfzlMB7PodK7o8NBD8outJGS tsL2GRX24QvvBuusJdMiLGpNz3uqyqwzC5w0Fd34E6G94806fwARAQABzSJDw6lkcmljIExl IEdvYXRlciA8Y2xnQHJlZGhhdC5jb20+wsGRBBMBCAA7FiEEoPZlSPBIlev+awtgUaNDx8/7 7KEFAmTLlVECGwMFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgkQUaNDx8/77KG0eg// S0zIzTcxkrwJ/9XgdcvVTnXLVF9V4/tZPfB7sCp8rpDCEseU6O0TkOVFoGWM39sEMiQBSvyY lHrP7p7E/JYQNNLh441MfaX8RJ5Ul3btluLapm8oHp/vbHKV2IhLcpNCfAqaQKdfk8yazYhh EdxTBlzxPcu+78uE5fF4wusmtutK0JG0sAgq0mHFZX7qKG6LIbdLdaQalZ8CCFMKUhLptW71 xe+aNrn7hScBoOj2kTDRgf9CE7svmjGToJzUxgeh9mIkxAxTu7XU+8lmL28j2L5uNuDOq9vl hM30OT+pfHmyPLtLK8+GXfFDxjea5hZLF+2yolE/ATQFt9AmOmXC+YayrcO2ZvdnKExZS1o8 VUKpZgRnkwMUUReaF/mTauRQGLuS4lDcI4DrARPyLGNbvYlpmJWnGRWCDguQ/LBPpbG7djoy k3NlvoeA757c4DgCzggViqLm0Bae320qEc6z9o0X0ePqSU2f7vcuWN49Uhox5kM5L86DzjEQ RHXndoJkeL8LmHx8DM+kx4aZt0zVfCHwmKTkSTQoAQakLpLte7tWXIio9ZKhUGPv/eHxXEoS 0rOOAZ6np1U/xNR82QbF9qr9TrTVI3GtVe7Vxmff+qoSAxJiZQCo5kt0YlWwti2fFI4xvkOi V7lyhOA3+/3oRKpZYQ86Frlo61HU3r6d9wzOwU0EW7yjdQEQALyDNNMw/08/fsyWEWjfqVhW pOOrX2h+z4q0lOHkjxi/FRIRLfXeZjFfNQNLSoL8j1y2rQOs1j1g+NV3K5hrZYYcMs0xhmrZ KXAHjjDx7FW3sG3jcGjFW5Xk4olTrZwFsZVUcP8XZlArLmkAX3UyrrXEWPSBJCXxDIW1hzwp bV/nVbo/K9XBptT/wPd+RPiOTIIRptjypGY+S23HYBDND3mtfTz/uY0Jytaio9GETj+fFis6 TxFjjbZNUxKpwftu/4RimZ7qL+uM1rG1lLWc9SPtFxRQ8uLvLOUFB1AqHixBcx7LIXSKZEFU CSLB2AE4wXQkJbApye48qnZ09zc929df5gU6hjgqV9Gk1rIfHxvTsYltA1jWalySEScmr0iS YBZjw8Nbd7SxeomAxzBv2l1Fk8fPzR7M616dtb3Z3HLjyvwAwxtfGD7VnvINPbzyibbe9c6g LxYCr23c2Ry0UfFXh6UKD83d5ybqnXrEJ5n/t1+TLGCYGzF2erVYGkQrReJe8Mld3iGVldB7 JhuAU1+d88NS3aBpNF6TbGXqlXGF6Yua6n1cOY2Yb4lO/mDKgjXd3aviqlwVlodC8AwI0Sdu jWryzL5/AGEU2sIDQCHuv1QgzmKwhE58d475KdVX/3Vt5I9kTXpvEpfW18TjlFkdHGESM/Jx IqVsqvhAJkalABEBAAHCwV8EGAECAAkFAlu8o3UCGwwACgkQUaNDx8/77KEhwg//WqVopd5k 8hQb9VVdk6RQOCTfo6wHhEqgjbXQGlaxKHoXywEQBi8eULbeMQf5l4+tHJWBxswQ93IHBQjK yKyNr4FXseUI5O20XVNYDJZUrhA4yn0e/Af0IX25d94HXQ5sMTWr1qlSK6Zu79lbH3R57w9j hQm9emQEp785ui3A5U2Lqp6nWYWXz0eUZ0Tad2zC71Gg9VazU9MXyWn749s0nXbVLcLS0yop s302Gf3ZmtgfXTX/W+M25hiVRRKCH88yr6it+OMJBUndQVAA/fE9hYom6t/zqA248j0QAV/p LHH3hSirE1mv+7jpQnhMvatrwUpeXrOiEw1nHzWCqOJUZ4SY+HmGFW0YirWV2mYKoaGO2YBU wYF7O9TI3GEEgRMBIRT98fHa0NPwtlTktVISl73LpgVscdW8yg9Gc82oe8FzU1uHjU8b10lU XOMHpqDDEV9//r4ZhkKZ9C4O+YZcTFu+mvAY3GlqivBNkmYsHYSlFsbxc37E1HpTEaSWsGfA HQoPn9qrDJgsgcbBVc1gkUT6hnxShKPp4PlsZVMNjvPAnr5TEBgHkk54HQRhhwcYv1T2QumQ izDiU6iOrUzBThaMhZO3i927SG2DwWDVzZltKrCMD1aMPvb3NU8FOYRhNmIFR3fcalYr+9gD uVKe8BVz4atMOoktmt0GWTOC8P4= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -49 X-Spam_score: -5.0 X-Spam_bar: ----- X-Spam_report: (-5.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.903, 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 5/21/25 10:25, John Levon wrote: > On Wed, May 21, 2025 at 10:11:06AM +0200, Cédric Le Goater wrote: > >>> - * Fill in @info with information on the region given by @info->index. >>> + * Fill in @info (and optionally @fd) with information on the region given >>> + * by @info->index. >> >> The whole VFIODeviceIOOps struct needs better documentation. The arguments >> are missing. > > Will add another preparatory patch, thanks. > >>> @@ -29,6 +29,7 @@ typedef struct VFIORegion { >>> uint32_t nr_mmaps; >>> VFIOMmap *mmaps; >>> uint8_t nr; /* cache the region number for debug */ >>> + int fd; /* fd to mmap() region */ >> >> Could you split this change ? I am not sure it is needed. > > The idea was to avoid having every bit of code that needed the region fd having > to remember to do: > >>> @@ -278,7 +283,7 @@ int vfio_region_mmap(VFIORegion *region) >>> region->mmaps[i].mmap = mmap(map_align, region->mmaps[i].size, prot, >>> MAP_SHARED | MAP_FIXED, >>> - region->vbasedev->fd, >>> + region->fd, >> >> Would this work ? >> >> vbasedev->region_fds ? vbasedev->region_fds[region->nr] : vbasedev->fd, > > That is, region->fd is *always* correct, and there is less chance of a bug where > somebody incorrectly uses vbasedev fd instead. IMO "region->fd" is much > cleaner/clearer. maybe. It's only used in one place : vfio_region_mmap(). I think caching the fd value under VFIORegion is overkill. Thanks, C. > > But, if you don't like that, yes, I can drop region->fd in favour of the above. > > thanks > john >