From patchwork Mon Jul 10 10:07:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13306684 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 BB51AEB64D9 for ; Mon, 10 Jul 2023 10:08:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qIno3-0003vM-U1; Mon, 10 Jul 2023 06:07:47 -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 1qIno2-0003uI-MX for qemu-devel@nongnu.org; Mon, 10 Jul 2023 06:07:46 -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 1qIno1-0004or-6A for qemu-devel@nongnu.org; Mon, 10 Jul 2023 06:07:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688983664; 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=2RlCAvRjZ5/LfrOrTT8T4Hqv6jYLbdlgGcFAODbrGDM=; b=Ln+1bO9OlPlogXtnOMqigAFMwFrIp1USCj6GVyqPuAiXTgI/MzYROct15P//vug76HRXeC IyYt/WgSY0Brvekfi2vQa/QsxSIO+jRly/t1Qz/BpKBFXA+073dol5dY+xrwle6ZBkD+H4 1CLZ3N9pS5TxH0pM4aA+ty5oDhyq9kE= 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-673-2R8R2_5JOoeXcmIPWK6R2Q-1; Mon, 10 Jul 2023 06:07:39 -0400 X-MC-Unique: 2R8R2_5JOoeXcmIPWK6R2Q-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 B8660800159; Mon, 10 Jul 2023 10:07:38 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.194.160]) by smtp.corp.redhat.com (Postfix) with ESMTP id C8F7C111CA01; Mon, 10 Jul 2023 10:07:36 +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 6/7] virtio-mem: Prepare for device unplug support Date: Mon, 10 Jul 2023 12:07:13 +0200 Message-ID: <20230710100714.228867-7-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 In many cases, blindly unplugging a virtio-mem device is problematic. We can only safely remove a device once: * The guest is not expecting to be able to read unplugged memory (unplugged-inaccessible == on) * The virtio-mem device does not have memory plugged (size == 0) * The virtio-mem device does not have outstanding requests to the VM to plug memory (requested-size == 0) So let's add a callback to the virtio-mem device class to check for that. We'll wire-up virtio-mem-pci next. Signed-off-by: David Hildenbrand --- hw/virtio/virtio-mem.c | 25 +++++++++++++++++++++++++ include/hw/virtio/virtio-mem.h | 1 + 2 files changed, 26 insertions(+) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index ec0ae32589..27b3aac87c 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -1483,6 +1483,30 @@ static void virtio_mem_rdm_unregister_listener(RamDiscardManager *rdm, QLIST_REMOVE(rdl, next); } +static void virtio_mem_unplug_request_check(VirtIOMEM *vmem, Error **errp) +{ + if (vmem->unplugged_inaccessible == ON_OFF_AUTO_OFF) { + /* + * We could allow it with a usable region size of 0, but let's just + * not care about that legacy setting. + */ + error_setg(errp, "virtio-mem device cannot get unplugged while" + " '" VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP "' != 'on'"); + return; + } + + if (vmem->size) { + error_setg(errp, "virtio-mem device cannot get unplugged while" + " '" VIRTIO_MEM_SIZE_PROP "' != '0'"); + return; + } + if (vmem->requested_size) { + error_setg(errp, "virtio-mem device cannot get unplugged while" + " '" VIRTIO_MEM_REQUESTED_SIZE_PROP "' != '0'"); + return; + } +} + static void virtio_mem_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); @@ -1505,6 +1529,7 @@ static void virtio_mem_class_init(ObjectClass *klass, void *data) vmc->get_memory_region = virtio_mem_get_memory_region; vmc->add_size_change_notifier = virtio_mem_add_size_change_notifier; vmc->remove_size_change_notifier = virtio_mem_remove_size_change_notifier; + vmc->unplug_request_check = virtio_mem_unplug_request_check; rdmc->get_min_granularity = virtio_mem_rdm_get_min_granularity; rdmc->is_populated = virtio_mem_rdm_is_populated; diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h index f15e561785..ab0fe2b4f2 100644 --- a/include/hw/virtio/virtio-mem.h +++ b/include/hw/virtio/virtio-mem.h @@ -98,6 +98,7 @@ struct VirtIOMEMClass { MemoryRegion *(*get_memory_region)(VirtIOMEM *vmem, Error **errp); void (*add_size_change_notifier)(VirtIOMEM *vmem, Notifier *notifier); void (*remove_size_change_notifier)(VirtIOMEM *vmem, Notifier *notifier); + void (*unplug_request_check)(VirtIOMEM *vmem, Error **errp); }; #endif