From patchwork Thu Nov 25 17:44:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 518203 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 5F977C433EF for ; Thu, 25 Nov 2021 17:46:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243657AbhKYRuG (ORCPT ); Thu, 25 Nov 2021 12:50:06 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:24835 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232378AbhKYRsF (ORCPT ); Thu, 25 Nov 2021 12:48:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637862293; 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=e7BvKG8FTSCUywCGOxNtwP0noXjOs1TD9Frr4bEkwQo=; b=LGOR/aRJGcINTJtnI3WCI/stW2mGLxtDtzduwy+Wu14uREu8LHB7hjx94QfxW41ge7DYTf fVx2S845KmNd2A+BxuPBGsTn7xvNSkxnqVJpYztFt69wLSanuUj2OmBDYAYJfquHH2l+E2 4CvRfm2VjCMARsvkshLWqE3j0fQejvk= Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-11-f_nCTLyBOPKCb6UfP8Xb-A-1; Thu, 25 Nov 2021 12:44:52 -0500 X-MC-Unique: f_nCTLyBOPKCb6UfP8Xb-A-1 Received: by mail-ed1-f71.google.com with SMTP id eg20-20020a056402289400b003eb56fcf6easo5950180edb.20 for ; Thu, 25 Nov 2021 09:44:52 -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=e7BvKG8FTSCUywCGOxNtwP0noXjOs1TD9Frr4bEkwQo=; b=hrMnHlFdef3ufvS4yMfJ5l019A+rqpZMCLUBd82sFNmK1+mNdOSrJNEi7cbNTMnH7L LpNmm5LNspXodcgw8icCebZ1B3Sh/QVbfDeqS3yCfT9257uxBFzdf6TGOBORTeMW0pdc 5N4QomG6wEnJnQXwSqr8zPbF7IoRAtd5LL/GX8nWrHAMP4896hJ7HtKM+emKmrEQW1iU ie2b++k/UkK2ImcL7XOasWn1RHg0P1yd4DYE5+vXmZctX+dC88YOFM+GOyS3Jpbb5W5I l//cvYcwC7nHEpi5wJu3CiuamEhLZOD1+KASA3/fDj6kTcgOxxVGRwT+MgY9TKO75J1+ x82g== X-Gm-Message-State: AOAM531ZZ761a1yF76b+ebRatA4nUwxdp0+/nYMdu5GZPCdXnsj4/txd 3uE9nzp5ld+yANH8XCGVQ0COgeuj8awyQIWtp9TTKSnqPe/AxpgSxSTzW3txm8J7Ho7ZzsGsFP6 BMWQwmwdbZUZb0SgVSZ0FarYwOGAq X-Received: by 2002:a05:6402:26c5:: with SMTP id x5mr41644309edd.198.1637862291205; Thu, 25 Nov 2021 09:44:51 -0800 (PST) X-Google-Smtp-Source: ABdhPJwpwEn3VYvVMPaGoZd0qGJp74+cDdsbX2UWjVLjI4yEEPSqkH08d/TIHMG/MWFEShL7tUlQ4g== X-Received: by 2002:a05:6402:26c5:: with SMTP id x5mr41644274edd.198.1637862291043; Thu, 25 Nov 2021 09:44:51 -0800 (PST) Received: from redhat.com ([176.12.197.47]) by smtp.gmail.com with ESMTPSA id og14sm1925383ejc.107.2021.11.25.09.44.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Nov 2021 09:44:50 -0800 (PST) Date: Thu, 25 Nov 2021 12:44:48 -0500 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , linux-bluetooth@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH] Bluetooth: virtio_bt: fix device removal Message-ID: <20211125174200.133230-1-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-bluetooth@vger.kernel.org Device removal is clearly out of virtio spec: it attempts to remove unused buffers from a VQ before invoking device reset. To fix, make open/close NOPs and do all cleanup/setup in probe/remove. The cost here is a single skb wasted on an unused bt device - which seems modest. NB: with this fix in place driver still suffers from a race condition if an interrupt triggers while device is being reset. Work on a fix for that issue is in progress. Signed-off-by: Michael S. Tsirkin --- Note: completely untested, in particular the device isn't supported in QEMU. Please do not queue directly - please help review and test and ack, and I will queue this together with reset fixes. Thanks! drivers/bluetooth/virtio_bt.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/bluetooth/virtio_bt.c b/drivers/bluetooth/virtio_bt.c index 24a9258962fa..aea33ba9522c 100644 --- a/drivers/bluetooth/virtio_bt.c +++ b/drivers/bluetooth/virtio_bt.c @@ -50,8 +50,11 @@ static int virtbt_add_inbuf(struct virtio_bluetooth *vbt) static int virtbt_open(struct hci_dev *hdev) { - struct virtio_bluetooth *vbt = hci_get_drvdata(hdev); + return 0; +} +static int virtbt_open_vdev(struct virtio_bluetooth *vbt) +{ if (virtbt_add_inbuf(vbt) < 0) return -EIO; @@ -61,7 +64,11 @@ static int virtbt_open(struct hci_dev *hdev) static int virtbt_close(struct hci_dev *hdev) { - struct virtio_bluetooth *vbt = hci_get_drvdata(hdev); + return 0; +} + +static int virtbt_close_vdev(struct virtio_bluetooth *vbt) +{ int i; cancel_work_sync(&vbt->rx); @@ -351,8 +358,14 @@ static int virtbt_probe(struct virtio_device *vdev) goto failed; } + virtio_device_ready(vdev); + if (virtbt_open_vdev(vbt)) + goto open_failed; + return 0; +open_failed: + hci_free_dev(hdev); failed: vdev->config->del_vqs(vdev); return err; @@ -365,6 +378,7 @@ static void virtbt_remove(struct virtio_device *vdev) hci_unregister_dev(hdev); vdev->config->reset(vdev); + virtbt_close_vdev(vbt); hci_free_dev(hdev); vbt->hdev = NULL;