From nobody Mon Feb 9 06:34:02 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; envelope-from=libvir-list-bounces@redhat.com; helo=mx1.redhat.com; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass(p=none dis=none) header.from=redhat.com Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mx.zohomail.com with SMTPS id 1531211839132717.6751078806088; Tue, 10 Jul 2018 01:37:19 -0700 (PDT) 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 mx1.redhat.com (Postfix) with ESMTPS id CA2A2307D864; Tue, 10 Jul 2018 08:37:17 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 920DF5DD77; Tue, 10 Jul 2018 08:37:17 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 45B38264D3; Tue, 10 Jul 2018 08:37:17 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id w6A8b1w5007801 for ; Tue, 10 Jul 2018 04:37:02 -0400 Received: by smtp.corp.redhat.com (Postfix) id DB8D67C55; Tue, 10 Jul 2018 08:37:01 +0000 (UTC) Received: from angien.brq.redhat.com (unknown [10.43.2.136]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7E7227C51 for ; Tue, 10 Jul 2018 08:37:01 +0000 (UTC) From: Peter Krempa To: libvir-list@redhat.com Date: Tue, 10 Jul 2018 10:44:42 +0200 Message-Id: <55ed40b52005c1d00d393d8bd4980099ae3e742f.1531212176.git.pkrempa@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-loop: libvir-list@redhat.com Subject: [libvirt] [PATCH 2/9] qemu: domain: Reject copy_on_read for read-only disks X-BeenThere: libvir-list@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Development discussions about the libvirt library & tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Tue, 10 Jul 2018 08:37:18 +0000 (UTC) X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" The sectors read from the backing image need to be written to the top level image. If a disk is marked read-only the image can't be written. QEMU handled that by disabling copy_on_read and reporting a warning: -drive file=3D/var/lib/libvirt/images/c,format=3Dqcow2,if=3Dnone, id=3Ddrive-scsi0-0-1,readonly=3Don,copy-on-read=3Don: warning: disabling copy-on-read on read-only drive Signed-off-by: Peter Krempa Reviewed-by: J=EF=BF=BDn Tomko --- src/qemu/qemu_domain.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index e29d01c828..0821ce769b 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -4650,6 +4650,13 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskD= ef *disk, return -1; } + if (disk->src->readonly && disk->copy_on_read =3D=3D VIR_TRISTATE_SWIT= CH_ON) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("copy_on_read is not compatible with read-only di= sk '%s'"), + disk->dst); + return -1; + } + if (disk->geometry.cylinders > 0 && disk->geometry.heads > 0 && disk->geometry.sectors > 0) { --=20 2.16.2 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list