From nobody Tue Jun 30 13:54:46 2026 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 AD091C433F5 for ; Fri, 14 Jan 2022 21:43:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229927AbiANVnf (ORCPT ); Fri, 14 Jan 2022 16:43:35 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:34679 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229903AbiANVnd (ORCPT ); Fri, 14 Jan 2022 16:43:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1642196613; 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; bh=H65UNYpk1YgIkr6+F7jbPWFp6tYbCp821iY0zXAi0/8=; b=R7S67hf8tcGNk03u8H4xDibZtHhRcUfnwtlbv0FaLLxpF0Z+PNqMoDpwmxHno4SpGl1AEC hCR1k33Kk8TCctht9GTsX3fLtJ5ui3eo+2R3Kw7w8C4njWHIhLVOJ3ooPrkgS7q5wek4Cc nPypzHAPP5IrI8q6wcyEPBAYZpcISzU= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-81-MFEb3JWwN3OwKU56qgvwjQ-1; Fri, 14 Jan 2022 16:43:31 -0500 X-MC-Unique: MFEb3JWwN3OwKU56qgvwjQ-1 Received: by mail-ed1-f72.google.com with SMTP id z8-20020a056402274800b003f8580bfb99so9268681edd.11 for ; Fri, 14 Jan 2022 13:43:31 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=H65UNYpk1YgIkr6+F7jbPWFp6tYbCp821iY0zXAi0/8=; b=A307Y/hXf1pnCsHeWN6NXAWj6yhhWDZEg2Vu821jvyB00UCUaZdYXh5xEkq/9vypYv FzgXmWbSkpUoBaR71BHmGMAAoblgL8Y3S+4c40OR0PcF7hIzX/XsDKhTHXSMIaXxp+NX +oV+1557ThlVDGpGeaX09Mwpk7beAUllNx7ZvewgLfl6vvFhNz1vQjE67k3Hv+ep1guH 06cTeqLPYh9v0ZYhDCSO2Q5SfD8lgXtpY0qcRYTaw1WIybrfocCrOZmWuEDozTtQvM3Z 1VdUi6OAeap7pfkZmdCTSDbVNvxEmoI2jNbmCN253/INn9W4uTce9n4JbGSzJad9zs+Q SzWw== X-Gm-Message-State: AOAM530pDaHDgn6kkK0XayILbJlzsZ4ovb4st6eaUMXoUQx2yMVfbQvy DwLG8HTvbvwmt8f7FTeL3BDaozXvTp3UpiFFcLahYlodj1ZlCZevQ1HTNUDuUR0uzlWkuihukg8 Pa+gjFkzSuOd1SSWradx4Tbu6uiT5OYzvrpEgS8iCwm2if6dDL44b3UM35hL9ze0ACGKBwA== X-Received: by 2002:a05:6402:27d1:: with SMTP id c17mr10483759ede.128.1642196609916; Fri, 14 Jan 2022 13:43:29 -0800 (PST) X-Google-Smtp-Source: ABdhPJwX+X4YHjBMDl2PYMvPClJyagNr+C+tepnu7ca8BYRhvwykdVnYrSL9WI3b0URVZRj1HoAt8A== X-Received: by 2002:a05:6402:27d1:: with SMTP id c17mr10483746ede.128.1642196609685; Fri, 14 Jan 2022 13:43:29 -0800 (PST) Received: from redhat.com ([2.55.154.210]) by smtp.gmail.com with ESMTPSA id c19sm2755020ede.47.2022.01.14.13.43.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Jan 2022 13:43:29 -0800 (PST) Date: Fri, 14 Jan 2022 16:43:26 -0500 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Jason Wang , virtualization@lists.linux-foundation.org Subject: [PATCH] virtio_mem: break device on remove Message-ID: <20220114214324.239444-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" A common pattern for device reset is currently: vdev->config->reset(vdev); .. cleanup .. reset prevents new interrupts from arriving and waits for interrupt handlers to finish. However if - as is common - the handler queues a work request which is flushed during the cleanup stage, we have code adding buffers / trying to get buffers while device is reset. Not good. This was reproduced by running modprobe virtio_console modprobe -r virtio_console in a loop, and this reasoning seems to apply to virtio mem though I could not reproduce it there. Fix this up by calling virtio_break_device + flush before reset. Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_mem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 38becd8d578c..33b8a118a3ae 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -2888,6 +2888,8 @@ static void virtio_mem_remove(struct virtio_device *v= dev) virtio_mem_deinit_hotplug(vm); =20 /* reset the device and cleanup the queues */ + virtio_break_device(vdev); + flush_work(&vm->wq); virtio_reset_device(vdev); vdev->config->del_vqs(vdev); =20 --=20 MST