From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.openvz.org (mail.openvz.org [69.168.225.77]) by lore.virtuozzo.com (Postfix) with ESMTPS id 1E65A812AD for ; Wed, 4 Nov 2026 20:10:06 +0000 (UTC) Received: from mail.openvz.org (localhost [127.0.0.1]) by mail.openvz.org (8.14.4/8.14.4) with ESMTP id 6A4K8kbv026610; Wed, 4 Nov 2026 23:08:47 +0300 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.openvz.org 6A4K8kbv026610 Authentication-Results: mail.openvz.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=virtuozzo.com header.i=@virtuozzo.com header.b="gYX9SGT/" Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by mail.openvz.org (8.14.4/8.14.4) with ESMTP id 6A4K8i5b026600 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=FAIL) for ; Wed, 4 Nov 2026 23:08:44 +0300 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.openvz.org 6A4K8i5b026600 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-48e011829easo696689f8f.3 for ; Wed, 04 Nov 2026 12:08:44 -0800 (PST) X-Gm-Message-State: APuU4Z/K2eWHv2+mbnoi7FRH0DXGmjFsIzCGjQDjWXZx1MEuvOHSc8yw mcrtOtxbybea45zGmkVQHQaHCOkOV5kmoJOjDkP6BYwG8xElXe2GokkcUOkp+0izW18UbIy7Zn+ gB16jHC8eSj/PcYAZRPUCYIbTVUEBxKweIfhfsHtDJQA/EgjcIidXkA== X-Gm-Gg: AYBFou3nhnChojAvPPLcuVF1u8HUmRb+AXSbCQaEfEkCEpa1yQPV8rlJwTzEMAnfVWE 6Jhy8vJ6gQsFfw+XJFXqjV6+wn7Gfm06cYDq0X+W/i+uJgsjfNgBpKyyvtmUOkn+9UJJ/j4TXKs suebZ8vAefEe50OIgrP+HL2+LiBNvv0vIJZiIlOWlz4vQCYNzF225x+HWH0E69aP4AhAuP/mOWE KIIgyYR4dJHafJPFd+RpNbcz13BwyEiWJXpVl6BuVUjPX/nxzNzUU5Ln76qqj7BE+hs61/Hvu/S 8JDl/y47SN5v5IuDrSjd/Acx8wI8o7CL/IuJw+weUvDpAR+WIgo0Fd0FXKtFzfcNgksBWWttY7h IAkbM4w3s34YWhHRkYQ== X-Received: by 2002:a05:6000:420d:b0:490:a481:7ac8 with SMTP id ffacd0b85a97d-490a4817c00mr3199368f8f.29.1793822923911; Wed, 04 Nov 2026 12:08:43 -0800 (PST) X-Received: by 2002:a05:6000:420d:b0:490:a481:7ac8 with SMTP id ffacd0b85a97d-490a4817c00mr3199339f8f.29.1793822923439; Wed, 04 Nov 2026 12:08:43 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1793822923; cv=none; d=google.com; s=arc-20260327; b=WxkSLDGLDJMSEHJXquxzlME4fRSF95zSeEv5bafl1drNUtiHeYY1E0UuswftJXHERZ KvM39ny+qZ0SjRgspi5MUj2/Jns2nMzp45xrWbVrIXODISCDDw9Xj1XXvnlv5cMTiMsD B4vM+XzSNfL0QCSUfqyZ5xI2h/GDz79+cgwlmyJDjmP/EEvq8R1gy+cfUPqodadlrnd7 ByegK3fSMHA3LXZCAge/bv8KsaxGsfPYDi/YjZ7Z8zkF0n+eMVAxXmPOlrAR2bvPpwG1 mzyyvo3gnoN7ysX1Jc7EMQhAnU4xA5j/7/vjiqUVON6CzKNV72t2uIo9sz9d07gt200b EjNw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=message-id:date:references:in-reply-to:cc:to:from:subject :content-transfer-encoding:mime-version:dkim-signature; bh=bMG4qCFNUk7byJbTK5ZgMbJ1kNcozcOcDf9+QdpxT1g=; fh=5AmFLEo6nHxL6WDW39LXC01IwU+CKjcYMpOuqqVTSIM=; b=YUxJC/iNTzaafgH/jspIMEksRV6ykHUTbmlpRtAsp1+0yihHR8wNll4I/qhZLyKSTO SeqL4nPIh+9qi53U7aozpScx7OzM6PFHK4EYLbIxkakIFKa7+GE3Nhj/Sxk1JsM9SkUi NycNU9ey6fj05PYITPfMKOS15fuDWYt8D4rsEh7/D2r2Y9dh4m42hgLNHPoinNwK+QRW wYotIKhIwBSJJnazIcDkgroJyQVAB+7uIoNfw6MjFfnJE8fUaHzNvm+fsEkJynj0xUmi Yu1V2d6gtgrl5omcaBKqZaQcE0pb/EiWZGNPlDXz5JKtRJvOWkRcd6kamhWALke1meih l92w==; dara=google.com ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b="gYX9SGT/"; spf=pass (google.com: domain of khorenko@virtuozzo.com designates 130.117.225.111 as permitted sender) smtp.mailfrom=khorenko@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com Received: from relay.virtuozzo.com (relay.virtuozzo.com. [130.117.225.111]) by mx.google.com with ESMTPS id ffacd0b85a97d-48fef3f32cesi5246761f8f.312.2026.11.04.12.08.43 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Nov 2026 12:08:43 -0800 (PST) Received-SPF: pass (google.com: domain of khorenko@virtuozzo.com designates 130.117.225.111 as permitted sender) client-ip=130.117.225.111; Authentication-Results: mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b="gYX9SGT/"; spf=pass (google.com: domain of khorenko@virtuozzo.com designates 130.117.225.111 as permitted sender) smtp.mailfrom=khorenko@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Message-Id:Date:From:Subject:Content-Type: MIME-Version; bh=bMG4qCFNUk7byJbTK5ZgMbJ1kNcozcOcDf9+QdpxT1g=; b=gYX9SGT/ptOJ 0KlSj/GVR2cNWuxSo72bDyqIRMPPPylDdikjIy4Zp0OfFS/g/Uswbku4I+Q+MFuLwo3iM7SXJ+Rsk Q2oqg6x5li5ziW8vLUYKKhOzipnWY7trAcq93+lLpUzN72rlYtk3Pkz73TEn7PHu1uYt1eUzryFoD r6/gkyuxLihrdefWrVHOaRH+4oJbGxNbO+UsRX6f/f2tbuPjZjk9KHiMJcrMim2SkpKEW7H2DZlG3 IF0gliW00SaVqFy5Wh2muz6pBjNS+x3w6VdB0aj/cD9l8Q8TjUcrtBaxP3yv2xqdf3hcOr5BHTppU mun82YXK4yeUNF9WwwWg6Q==; Received: from ch-demo-asa.virtuozzo.com ([130.117.225.8] helo=f0.sw.ru) by relay.virtuozzo.com with esmtp (Exim 4.96) (envelope-from ) id 1xOhDp-000aSY-2O; Wed, 04 Nov 2026 21:08:41 +0100 MIME-Version: 1.0 From: Konstantin Khorenko To: Andrey Drobyshev In-Reply-To: <20261030144933.944360-1-andrey.drobyshev@virtuozzo.com> References: <20261030144933.944360-1-andrey.drobyshev@virtuozzo.com> Date: Wed, 04 Nov 2026 21:08:34 +0100 Message-Id: <179382291493.2764784.410820796002692056.b4-review@b4> X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2158; i=khorenko@virtuozzo.com; h=from:subject:message-id; bh=EkxH8bTWzuY/lfU4M7Sc2bAu9RosX8DkD6PslRtXjwY=; b=owEBbQKS/ZANAwAKAVGWCkf5YVwqAcsmYgBq65DJ7isihX+HTOgfQNmcEx9q5CAcTJyQXcSFY faR3vntho2JAjMEAAEKAB0WIQRWD23IPcXT0GO9CCxRlgpH+WFcKgUCauuQyQAKCRBRlgpH+WFc KlzRD/9azl01xi1yp8zKAWpBh0lM760MhbLFd0MsUjC2qY8m52b7eUQpaX2Ob0jaR9jisfOv0Pr VolQ9qkggkxJxevg9YQ6mb+9apS+h1J3CA+9aPr7xT0zKuct7mOMptVnzef+6wWlZDP8Eg0PnQp 7fBcTK+eg0TwrebXR1aNQMPWHnNN1nGPR6Af2pD7tSeDw+tK08sZDXiS4ZRyVOAko2Wg+FlP+mh +KU5LoX3s/PnqfiiNiUUssPdSOyKZQEF119cvNUjowwxyJhALuUoggyAdqEspmgwgOYZ/a7ja+C 3zUWSfo3hbtsHoxqlKQJoBokC/SjTvJyPinYxqZiM/ZmAGUfT2cJPb6/UyCsPDC/PZNx8VRPrgy U48OYX7eLl93ZeVm04FTWh7Uwcx1A6ZXvD+ZWRY84YlBIk1DFAJfHRKSUtjYgBf9rK4pRaWs0su Qefa4jsJeuOZttevP0YZczctMg2Ric16yABC6NGeTlVdSI1iLUt4ZxETBHqyDHkTcl3UjkAhyfI Vja0jtW3tnI5ZQWth3vyPziyBcuIV3aPUYriKlVTIWkIIfzoedTX4ao3TN9PEY6LhDH1zouTb2X LJ79/SdmfjzSLPvaX3FshC5/SN0UXRbdHIm+c+jLTGeu0cLI66cgfrgqRroc3yzrLnrKrMDZIjy xEOCFs9znhotP/Q== X-Developer-Key: i=khorenko@virtuozzo.com; a=openpgp; fpr=560F6DC83DC5D3D063BD082C51960A47F9615C2A X-OZ-Fwd: true Cc: devel@openvz.org Subject: Re: [Devel] [PATCH hci-8.1 0/2] vfio: prevent kvm reference leak on qemu-update X-BeenThere: devel@openvz.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: OpenVZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: devel-bounces@openvz.org Errors-To: devel-bounces@openvz.org I won't apply this version, please send v2 with the changes below. On Fri, 30 Oct 2026 16:49:31 +0200, Andrey Drobyshev wrote: > Andrey Drobyshev (2): > vfio: move an open device's kvm reference when its group gets a new > kvm > KVM: remove the VM's debugfs directory when its fd is released What to change for v2: 1. Patch 1, code and commit message: do not change device->kvm under a driver that still uses it after open_device(). In tree that is KVMGT: it registers its page-track notifier on device->kvm at open and unregisters it from device->kvm at close. Check what the NVIDIA vGPU driver does with vdev->kvm after open and say in the message which driver the change was tested with. 2. Patch 1, code comment and commit message: give the real reason to skip NULL, the lock order (details in the patch reply), and drop "the new kvm, if any, arrives on its own". Update the kernel-doc of vfio_file_set_kvm() too. 3. Patch 1, commit message: add a Fixes tag for 2b48f52f2bff ("vfio: fix deadlock between group lock and kvm lock"). 4. Patch 2, code: at fd release remove only the directory. Keep freeing debugfs_stat_data in kvm_destroy_vm(), moved out from under the IS_ERR(kvm->debugfs_dentry) early return. This version has a use-after-free. 5. Patch 2, commit message: say that the destroy uevent no longer carries STATS_PATH, and that the stats go away for a VM that keeps running on its vcpu fds after the VM fd is closed. 6. Both patches: single space after a period, in the messages and in the new code comments, and add the Feature: line. 7. Cover letter: write one. Say what goes wrong on a live update of a vGPU VM, what each patch does, and how it was tested. In the subject "qemu-update" becomes "live update", and "kvm reference leak" covers patch 1 only. Separate, not needed for v2: 1. Patch 1 should go to mainline too, I created a task for that: https://virtuozzo.atlassian.net/browse/VSTOR-153437 Details on items 1-6 are in the replies to the patches. -- Konstantin Khorenko, Virtuozzo Linux Kernel Team _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel