From nobody Mon Feb 9 16:03:00 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1680546667; cv=none; d=zohomail.com; s=zohoarc; b=WUFK5qq5YQOPT0DAjbso9gEXcSfJkPMYdb4CBKr/81m6BSNiJ/6TVl1ks2/jQncDeN+YnjkjpeY38sewLGFrgCtUg3OAM6sXhWYP+X+66PZn+0Ev+uIj/mq0ySAmYekFNlJBpF9saUnA7BE6ynS+MQK/L7EMSNMEdW6Qt88Naq8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1680546667; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=oL+HrJxL6ytOleAzvmZ4SJ3Zeezd7vV75aui9s0hUdo=; b=LGXPWgS2dkMJJBacmpWK+afqto9dV7ParFSsIYd9RqOYhYTve/r/vzDqGtozkGc8XeAug3Bwpje1/BpCVz9IElRQQA3tTrpJPdiYooDQuTHCWA/zl3SNucaO3MtywyWDsoXh1WGNB1mQZkRLCQfPh2keubvkOuJoLobPkR5PSPA= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1680546667578353.87213781871947; Mon, 3 Apr 2023 11:31:07 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.517552.803069 (Exim 4.92) (envelope-from ) id 1pjOwt-0005JH-TH; Mon, 03 Apr 2023 18:30:35 +0000 Received: by outflank-mailman (output) from mailman id 517552.803069; Mon, 03 Apr 2023 18:30:35 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pjOwt-0005J6-PZ; Mon, 03 Apr 2023 18:30:35 +0000 Received: by outflank-mailman (input) for mailman id 517552; Mon, 03 Apr 2023 18:30:34 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pjOwr-0004HH-VE for xen-devel@lists.xenproject.org; Mon, 03 Apr 2023 18:30:34 +0000 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 9db74a78-d24d-11ed-85db-49a42c6b2330; Mon, 03 Apr 2023 20:30:33 +0200 (CEST) Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-281-cN00YhrQM7uB9EfAu9sSvQ-1; Mon, 03 Apr 2023 14:30:26 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 416D13C10EEF; Mon, 3 Apr 2023 18:30:12 +0000 (UTC) Received: from localhost (unknown [10.39.192.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id 751A6C15BA0; Mon, 3 Apr 2023 18:30:11 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 9db74a78-d24d-11ed-85db-49a42c6b2330 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680546631; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oL+HrJxL6ytOleAzvmZ4SJ3Zeezd7vV75aui9s0hUdo=; b=dI+yjjuDwKKViSZTb1wuclFWGfaAIY4B8fBgPsiEvcqMluIfiN33JcNCj4A5KlkR1WTkz6 vj61EvXAzYx80j80rRhCLyGfHn8Se3lfYfZD51uWRrbQzZRFUUapSK/N67fQDa9wTwq0O3 fum+ALo6iIoQJmuSCHUgxKt8wCcQc9Q= X-MC-Unique: cN00YhrQM7uB9EfAu9sSvQ-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Julia Suvorova , Stefan Hajnoczi , Kevin Wolf , Peter Lieven , Coiby Xu , xen-devel@lists.xenproject.org, Richard Henderson , Stefano Garzarella , , Eduardo Habkost , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Paul Durrant , "Richard W.M. Jones" , "Dr. David Alan Gilbert" , Marcel Apfelbaum , Aarushi Mehta , Stefano Stabellini , Fam Zheng , David Woodhouse , Stefan Weil , Juan Quintela , Xie Yongji , Hanna Reitz , Ronnie Sahlberg , eesposit@redhat.com, "Michael S. Tsirkin" , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Anthony Perard Subject: [PATCH 01/13] virtio-scsi: avoid race between unplug and transport event Date: Mon, 3 Apr 2023 14:29:52 -0400 Message-Id: <20230403183004.347205-2-stefanha@redhat.com> In-Reply-To: <20230403183004.347205-1-stefanha@redhat.com> References: <20230403183004.347205-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1680546669596100015 Content-Type: text/plain; charset="utf-8" Only report a transport reset event to the guest after the SCSIDevice has been unrealized by qdev_simple_device_unplug_cb(). qdev_simple_device_unplug_cb() sets the SCSIDevice's qdev.realized field to false so that scsi_device_find/get() no longer see it. scsi_target_emulate_report_luns() also needs to be updated to filter out SCSIDevices that are unrealized. These changes ensure that the guest driver does not see the SCSIDevice that's being unplugged if it responds very quickly to the transport reset event. Signed-off-by: Stefan Hajnoczi Reviewed-by: Michael S. Tsirkin Reviewed-by: Paolo Bonzini --- hw/scsi/scsi-bus.c | 3 ++- hw/scsi/virtio-scsi.c | 18 +++++++++--------- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index c97176110c..f9bd064833 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -487,7 +487,8 @@ static bool scsi_target_emulate_report_luns(SCSITargetR= eq *r) DeviceState *qdev =3D kid->child; SCSIDevice *dev =3D SCSI_DEVICE(qdev); =20 - if (dev->channel =3D=3D channel && dev->id =3D=3D id && dev->l= un !=3D 0) { + if (dev->channel =3D=3D channel && dev->id =3D=3D id && dev->l= un !=3D 0 && + qatomic_load_acquire(&dev->qdev.realized)) { store_lun(tmp, dev->lun); g_byte_array_append(buf, tmp, 8); len +=3D 8; diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 612c525d9d..000961446c 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -1063,15 +1063,6 @@ static void virtio_scsi_hotunplug(HotplugHandler *ho= tplug_dev, DeviceState *dev, SCSIDevice *sd =3D SCSI_DEVICE(dev); AioContext *ctx =3D s->ctx ?: qemu_get_aio_context(); =20 - if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) { - virtio_scsi_acquire(s); - virtio_scsi_push_event(s, sd, - VIRTIO_SCSI_T_TRANSPORT_RESET, - VIRTIO_SCSI_EVT_RESET_REMOVED); - scsi_bus_set_ua(&s->bus, SENSE_CODE(REPORTED_LUNS_CHANGED)); - virtio_scsi_release(s); - } - aio_disable_external(ctx); qdev_simple_device_unplug_cb(hotplug_dev, dev, errp); aio_enable_external(ctx); @@ -1082,6 +1073,15 @@ static void virtio_scsi_hotunplug(HotplugHandler *ho= tplug_dev, DeviceState *dev, blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL); virtio_scsi_release(s); } + + if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) { + virtio_scsi_acquire(s); + virtio_scsi_push_event(s, sd, + VIRTIO_SCSI_T_TRANSPORT_RESET, + VIRTIO_SCSI_EVT_RESET_REMOVED); + scsi_bus_set_ua(&s->bus, SENSE_CODE(REPORTED_LUNS_CHANGED)); + virtio_scsi_release(s); + } } =20 static struct SCSIBusInfo virtio_scsi_scsi_info =3D { --=20 2.39.2