{"id":1839911,"url":"http://patchwork.ozlabs.org/api/patches/1839911/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20230926185738.277351-19-david@redhat.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20230926185738.277351-19-david@redhat.com>","list_archive_url":null,"date":"2023-09-26T18:57:38","name":"[v4,18/18] virtio-mem: Mark memslot alias memory regions unmergeable","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"23cfc1af6b565d882d9f36dc6a1c941e7017af88","submitter":{"id":70402,"url":"http://patchwork.ozlabs.org/api/people/70402/?format=json","name":"David Hildenbrand","email":"david@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20230926185738.277351-19-david@redhat.com/mbox/","series":[{"id":374991,"url":"http://patchwork.ozlabs.org/api/series/374991/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=374991","date":"2023-09-26T18:57:23","name":"virtio-mem: Expose device memory through multiple memslots","version":4,"mbox":"http://patchwork.ozlabs.org/series/374991/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/1839911/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/1839911/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=hR12PzKX;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)"],"Received":["from lists.gnu.org (lists.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4Rw8Gw2MZfz1ynX\n\tfor ; Wed, 27 Sep 2023 05:01:28 +1000 (AEST)","from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from )\n\tid 1qlDIJ-0002M2-UY; Tue, 26 Sep 2023 15:00:28 -0400","from eggs.gnu.org ([2001:470:142:3::10])\n by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from ) id 1qlDI8-0001to-8e\n for qemu-devel@nongnu.org; Tue, 26 Sep 2023 15:00:16 -0400","from us-smtp-delivery-124.mimecast.com ([170.10.129.124])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from ) id 1qlDI4-0003Uq-Ix\n for qemu-devel@nongnu.org; Tue, 26 Sep 2023 15:00:15 -0400","from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com\n [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS\n (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id\n us-mta-281-t_nnSmVvNL-nvOoa5tOcxg-1; Tue, 26 Sep 2023 15:00:07 -0400","from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com\n [10.11.54.4])\n (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n (No client certificate requested)\n by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1DE3E811E8E;\n Tue, 26 Sep 2023 19:00:07 +0000 (UTC)","from t14s.fritz.box (unknown [10.39.192.33])\n by smtp.corp.redhat.com (Postfix) with ESMTP id B9B372026D4B;\n Tue, 26 Sep 2023 19:00:02 +0000 (UTC)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1695754811;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:cc:mime-version:mime-version:content-type:content-type:\n content-transfer-encoding:content-transfer-encoding:\n in-reply-to:in-reply-to:references:references;\n bh=jAvglJj91/o8R3ulPUvMP06jx5ezTDNURc+rL2BIGo4=;\n b=hR12PzKXXvgb//rP8/f7FQccH0FZyKQbaawQnhzy2V+TVcxtJRRVw2KKXx+SYqNZOyT8Ro\n 5EE4TTfACEKDkiFVFP0UbCGnrIPUetn+m6flyA9GOQMdfJ+qEczZxyWzHo4ju6C7Z+Qs/v\n KcrmJg5mJ+eLK0qbyMEAxfuXirZxXhg=","X-MC-Unique":"t_nnSmVvNL-nvOoa5tOcxg-1","From":"David Hildenbrand ","To":"qemu-devel@nongnu.org","Cc":"David Hildenbrand , Paolo Bonzini ,\n Igor Mammedov ,\n Xiao Guangrong ,\n \"Michael S. Tsirkin\" , Peter Xu ,\n\t=?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= ,\n Eduardo Habkost ,\n Marcel Apfelbaum ,\n Yanan Wang , Michal Privoznik ,\n\t=?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= ,\n Gavin Shan , Alex Williamson ,\n Stefan Hajnoczi ,\n \"Maciej S . Szmigiero\" , kvm@vger.kernel.org","Subject":"[PATCH v4 18/18] virtio-mem: Mark memslot alias memory regions\n unmergeable","Date":"Tue, 26 Sep 2023 20:57:38 +0200","Message-ID":"<20230926185738.277351-19-david@redhat.com>","In-Reply-To":"<20230926185738.277351-1-david@redhat.com>","References":"<20230926185738.277351-1-david@redhat.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","X-Scanned-By":"MIMEDefang 3.1 on 10.11.54.4","Received-SPF":"pass client-ip=170.10.129.124; envelope-from=david@redhat.com;\n 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,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001,\n SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"Let's mark the memslot alias memory regions as unmergable, such that\nflatview and vhost won't merge adjacent memory region aliases and we can\natomically map/unmap individual aliases without affecting adjacent\nalias memory regions.\n\nThis handles vhost and vfio in multiple-memslot mode correctly (which do\nnot support atomic memslot updates) and avoids the temporary removal of\nlarge memslots, which can be an expensive operation. For example, vfio\nmight have to unpin + repin a lot of memory, which is undesired.\n\nReviewed-by: Philippe Mathieu-Daudé \nSigned-off-by: David Hildenbrand \n---\n hw/virtio/virtio-mem.c | 6 ++++++\n 1 file changed, 6 insertions(+)","diff":"diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c\nindex e1e4250e69..9dc3c61b5a 100644\n--- a/hw/virtio/virtio-mem.c\n+++ b/hw/virtio/virtio-mem.c\n@@ -940,6 +940,12 @@ static void virtio_mem_prepare_memslots(VirtIOMEM *vmem)\n memory_region_init_alias(&vmem->memslots[idx], OBJECT(vmem), name,\n &vmem->memdev->mr, memslot_offset,\n memslot_size);\n+ /*\n+ * We want to be able to atomically and efficiently activate/deactivate\n+ * individual memslots without affecting adjacent memslots in memory\n+ * notifiers.\n+ */\n+ memory_region_set_unmergeable(&vmem->memslots[idx], true);\n }\n }\n \n","prefixes":["v4","18/18"]}