From patchwork Mon Jul 10 10:07:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13306688 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 3F240EB64DA for ; Mon, 10 Jul 2023 10:09:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qInny-0003r7-EP; Mon, 10 Jul 2023 06:07:42 -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 1qInnx-0003q7-6M for qemu-devel@nongnu.org; Mon, 10 Jul 2023 06:07:41 -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 1qInnv-0004nj-RC for qemu-devel@nongnu.org; Mon, 10 Jul 2023 06:07:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688983659; 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=yu36KmkVuZ8+kaM0iIdbgFGdigReU0ootcpoyySbSIU=; b=QT0IGN1woKXaJN3ytmPS9WrtI9OKyKADmqOej4wK+q7RSwgXWiiDcH7FiFKknitEwF/Kyf mZZH0FcqZLHD1CvsqhRk37BtoYLsH9Mp+oKMVe1ZFy+EU8HyD+NgFIIJqjjXGirkOGvejd c9hFjFaC0FGiRfYCvorJzpahnK4FM04= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-587-I-LOTxRlMA2qUNJtOjt9Sg-1; Mon, 10 Jul 2023 06:07:34 -0400 X-MC-Unique: I-LOTxRlMA2qUNJtOjt9Sg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CB40E101A54E; Mon, 10 Jul 2023 10:07:33 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.194.160]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3FB47111CA01; Mon, 10 Jul 2023 10:07:31 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: David Hildenbrand , Peter Maydell , Paolo Bonzini , Richard Henderson , Eduardo Habkost , "Michael S. Tsirkin" , Marcel Apfelbaum , Igor Mammedov , qemu-arm@nongnu.org, Gavin Shan , Mario Casquero Subject: [PATCH v3 4/7] virtio-md-pci: Handle unplug of virtio based memory devices Date: Mon, 10 Jul 2023 12:07:11 +0200 Message-ID: <20230710100714.228867-5-david@redhat.com> In-Reply-To: <20230710100714.228867-1-david@redhat.com> References: <20230710100714.228867-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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 While we fence unplug requests from the outside, the VM can still trigger unplug of virtio based memory devices, for example, in Linux doing on a virtio-mem-pci device: # echo 0 > /sys/bus/pci/slots/3/power While doing that is not really expected to work without harming the guest OS (e.g., removing a virtio-mem device while it still provides memory), let's make sure that we properly handle it on the QEMU side. We'll add support for unplugging of virtio-mem devices in some configurations next. Signed-off-by: David Hildenbrand --- hw/virtio/virtio-md-pci.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/hw/virtio/virtio-md-pci.c b/hw/virtio/virtio-md-pci.c index e849c3131d..a22a259e2d 100644 --- a/hw/virtio/virtio-md-pci.c +++ b/hw/virtio/virtio-md-pci.c @@ -14,6 +14,7 @@ #include "hw/virtio/virtio-md-pci.h" #include "hw/mem/memory-device.h" #include "qapi/error.h" +#include "qemu/error-report.h" void virtio_md_pci_pre_plug(VirtIOMDPCI *vmd, MachineState *ms, Error **errp) { @@ -74,7 +75,27 @@ void virtio_md_pci_unplug_request(VirtIOMDPCI *vmd, MachineState *ms, void virtio_md_pci_unplug(VirtIOMDPCI *vmd, MachineState *ms, Error **errp) { - /* We don't support hot unplug of virtio based memory devices */ + DeviceState *dev = DEVICE(vmd); + HotplugHandler *bus_handler = qdev_get_bus_hotplug_handler(dev); + MemoryDeviceState *md = MEMORY_DEVICE(vmd); + Error *local_err = NULL; + + /* Unplug the memory device while it is still realized. */ + memory_device_unplug(md, ms); + + if (bus_handler) { + hotplug_handler_unplug(bus_handler, dev, &local_err); + if (local_err) { + /* Not expected to fail ... but still try to recover. */ + memory_device_plug(md, ms); + error_propagate(errp, local_err); + return; + } + } else { + /* Very unexpected, but let's just try to do the right thing. */ + warn_report("Unexpected unplug of virtio based memory device"); + qdev_unrealize(dev); + } } static const TypeInfo virtio_md_pci_info = {