From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA0BCC433DF for ; Fri, 15 May 2020 16:47:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96C0F207F9 for ; Fri, 15 May 2020 16:47:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fwXZIv7Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726302AbgEOQr2 (ORCPT ); Fri, 15 May 2020 12:47:28 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:33578 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726023AbgEOQr2 (ORCPT ); Fri, 15 May 2020 12:47:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589561246; 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: in-reply-to:in-reply-to:references:references; bh=+vDoS6rtXmiEsFGa8fr+cErcnWf910dF9m0oUPGIPlo=; b=fwXZIv7ZX1m6jQ/UzVgA0B0vGspjBmUhFNNBx0nHnjwUXQh/QZrR/pDYivQ7mo+rUxtXdy ueen5MW6VW6mHVS4zKu0EVjXnVPe2ylRnKDsIf7Z3lgVtDfAa6e3bl8csm/O9HE+fVyFn6 rSZB+m7Mp17d+op6Kl+H6PFsUu2CK+Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-106-EOXWEmFjMLOHXnoe0r3qXA-1; Fri, 15 May 2020 12:47:23 -0400 X-MC-Unique: EOXWEmFjMLOHXnoe0r3qXA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D5807107AFC6; Fri, 15 May 2020 16:47:21 +0000 (UTC) Received: from work-vm (ovpn-114-149.ams2.redhat.com [10.36.114.149]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ED72C5D9F1; Fri, 15 May 2020 16:47:02 +0000 (UTC) Date: Fri, 15 May 2020 17:46:59 +0100 From: "Dr. David Alan Gilbert" To: David Hildenbrand Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, qemu-s390x@nongnu.org, Richard Henderson , Paolo Bonzini , Eduardo Habkost , "Michael S . Tsirkin" , Igor Mammedov Subject: Re: [PATCH v1 16/17] virtio-mem: Allow notifiers for size changes Message-ID: <20200515164659.GK2954@work-vm> References: <20200506094948.76388-1-david@redhat.com> <20200506094948.76388-17-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200506094948.76388-17-david@redhat.com> User-Agent: Mutt/1.13.4 (2020-02-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org * David Hildenbrand (david@redhat.com) wrote: > We want to send qapi events in case the size of a virtio-mem device > changes. This allows upper layers to always know how much memory is > actually currently consumed via a virtio-mem device. > > Unfortuantely, we have to report the id of our proxy device. Let's provide > an easy way for our proxy device to register, so it can send the qapi > events. Piggy-backing on the notifier infrastructure (although we'll > only ever have one notifier registered) seems to be an easy way. > > Cc: "Michael S. Tsirkin" > Cc: "Dr. David Alan Gilbert" > Cc: Igor Mammedov > Signed-off-by: David Hildenbrand Reviewed-by: Dr. David Alan Gilbert > --- > hw/virtio/virtio-mem.c | 21 ++++++++++++++++++++- > include/hw/virtio/virtio-mem.h | 5 +++++ > 2 files changed, 25 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c > index e25b2c74f2..88a99a0d90 100644 > --- a/hw/virtio/virtio-mem.c > +++ b/hw/virtio/virtio-mem.c > @@ -198,6 +198,7 @@ static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa, > } else { > vmem->size -= size; > } > + notifier_list_notify(&vmem->size_change_notifiers, &vmem->size); > return VIRTIO_MEM_RESP_ACK; > } > > @@ -253,7 +254,10 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem) > return -EBUSY; > } > bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size); > - vmem->size = 0; > + if (vmem->size != 0) { > + vmem->size = 0; > + notifier_list_notify(&vmem->size_change_notifiers, &vmem->size); > + } > > virtio_mem_resize_usable_region(vmem, vmem->requested_size, true); > return 0; > @@ -594,6 +598,18 @@ static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp) > return &vmem->memdev->mr; > } > > +static void virtio_mem_add_size_change_notifier(VirtIOMEM *vmem, > + Notifier *notifier) > +{ > + notifier_list_add(&vmem->size_change_notifiers, notifier); > +} > + > +static void virtio_mem_remove_size_change_notifier(VirtIOMEM *vmem, > + Notifier *notifier) > +{ > + notifier_remove(notifier); > +} > + > static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name, > void *opaque, Error **errp) > { > @@ -705,6 +721,7 @@ static void virtio_mem_instance_init(Object *obj) > VirtIOMEM *vmem = VIRTIO_MEM(obj); > > vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE; > + notifier_list_init(&vmem->size_change_notifiers); > > object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size, > NULL, NULL, NULL, &error_abort); > @@ -743,6 +760,8 @@ static void virtio_mem_class_init(ObjectClass *klass, void *data) > > vmc->fill_device_info = virtio_mem_fill_device_info; > 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; > } > > static const TypeInfo virtio_mem_info = { > diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h > index 27158cb611..5820b5c23e 100644 > --- a/include/hw/virtio/virtio-mem.h > +++ b/include/hw/virtio/virtio-mem.h > @@ -66,6 +66,9 @@ typedef struct VirtIOMEM { > /* block size and alignment */ > uint32_t block_size; > uint32_t migration_block_size; > + > + /* notifiers to notify when "size" changes */ > + NotifierList size_change_notifiers; > } VirtIOMEM; > > typedef struct VirtIOMEMClass { > @@ -75,6 +78,8 @@ typedef struct VirtIOMEMClass { > /* public */ > void (*fill_device_info)(const VirtIOMEM *vmen, VirtioMEMDeviceInfo *vi); > 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); > } VirtIOMEMClass; > > #endif > -- > 2.25.3 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK