From nobody Mon Feb 9 18:45:44 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 155049891457139.44860893582245; Mon, 18 Feb 2019 06:08:34 -0800 (PST) Received: from localhost ([127.0.0.1]:59117 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gvjaw-0003As-Ew for importer@patchew.org; Mon, 18 Feb 2019 09:08:30 -0500 Received: from eggs.gnu.org ([209.51.188.92]:59363) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gvjWr-0000Ah-Vy for qemu-devel@nongnu.org; Mon, 18 Feb 2019 09:04:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gvjWq-0004Un-23 for qemu-devel@nongnu.org; Mon, 18 Feb 2019 09:04:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60026) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gvjWi-0004QU-U7; Mon, 18 Feb 2019 09:04:09 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E35F213269C; Mon, 18 Feb 2019 14:04:07 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-116-155.ams2.redhat.com [10.36.116.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id CDBCD1024948; Mon, 18 Feb 2019 14:03:32 +0000 (UTC) From: Stefano Garzarella To: qemu-devel@nongnu.org Date: Mon, 18 Feb 2019 15:02:54 +0100 Message-Id: <20190218140301.197408-4-sgarzare@redhat.com> In-Reply-To: <20190218140301.197408-1-sgarzare@redhat.com> References: <20190218140301.197408-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 18 Feb 2019 14:04:07 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v5 03/10] virtio-blk: add "discard" and "write-zeroes" properties X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Laurent Vivier , Thomas Huth , Eduardo Habkost , qemu-block@nongnu.org, "Michael S. Tsirkin" , Jason Wang , Stefan Hajnoczi , "Dr . David Alan Gilbert" , Max Reitz , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" In order to avoid migration issues, we enable DISCARD and WRITE_ZEROES features only for machine type >=3D 4.0 As discussed with Michael S. Tsirkin and Stefan Hajnoczi on the list [1], DISCARD operation should not have security implications (eg. page cache attacks), so we can enable it by default. [1] https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg00504.html Suggested-by: Dr. David Alan Gilbert Reviewed-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Signed-off-by: Stefano Garzarella --- hw/block/virtio-blk.c | 4 ++++ hw/core/machine.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 7813237756..f7cd322811 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1027,6 +1027,10 @@ static Property virtio_blk_properties[] =3D { DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128), DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, IOThread *), + DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, + VIRTIO_BLK_F_DISCARD, true), + DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features, + VIRTIO_BLK_F_WRITE_ZEROES, true), DEFINE_PROP_END_OF_LIST(), }; =20 diff --git a/hw/core/machine.c b/hw/core/machine.c index 077fbd182a..766ca5899d 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -33,6 +33,8 @@ GlobalProperty hw_compat_3_1[] =3D { { "usb-kbd", "serial", "42" }, { "usb-mouse", "serial", "42" }, { "usb-kbd", "serial", "42" }, + { "virtio-blk-device", "discard", "false" }, + { "virtio-blk-device", "write-zeroes", "false" }, }; const size_t hw_compat_3_1_len =3D G_N_ELEMENTS(hw_compat_3_1); =20 --=20 2.20.1