From nobody Thu Nov 13 21:53:33 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.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; dkim=fail; spf=pass (zohomail.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 ARC-Seal: i=1; a=rsa-sha256; t=1583216494; cv=none; d=zohomail.com; s=zohoarc; b=SiQRBewUNrxw48YQB1hEsutu9d6g74lbahoxrn4WCI1t2ssGX29nK/wPKhVWF+iZEZfFvskctPp2nkYV+MwaDgN07ARlf6LsKfpXpX5tpoh1lvsQVttgN7C+b8YHs0rCztCFO60R4UIhhPscZiJOilIGkm41kNCpanRXy9EzPWo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1583216494; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:Sender:Subject:To; bh=A/eOvcKb8JVz1ZcZ5FOMoLl1euHQOYoYPOIh0aBaWBY=; b=bd5uyglH+/sav9lVZJMr+x7U9hO8Bv+sJIOJO/h3Z3u2MUT21MkXRzBeWNOsDIaKG25+z1g/KUGU4I0S30NwvOm5E8m+Tumr+H01C8VCGbBWQQyWtEp6+jSmqLTqXbFAO+NBTBgsQA2fB06Bv+sqsOtXdnP+RjCo+xHjEQ2s9D4= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.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 header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1583216494528363.94259262914954; Mon, 2 Mar 2020 22:21:34 -0800 (PST) Received: from localhost ([::1]:42722 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j90vs-0004aV-Lv for importer@patchew.org; Tue, 03 Mar 2020 01:21:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52165) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j90vE-000456-06 for qemu-devel@nongnu.org; Tue, 03 Mar 2020 01:20:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j90v9-0005zW-Pg for qemu-devel@nongnu.org; Tue, 03 Mar 2020 01:20:50 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:39189 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j90v9-0005zM-Ah for qemu-devel@nongnu.org; Tue, 03 Mar 2020 01:20:47 -0500 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-72-q28ttkMLOTeYZIpfM5O6dA-1; Tue, 03 Mar 2020 01:20:44 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7FE2619067E0; Tue, 3 Mar 2020 06:20:43 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-150.ams2.redhat.com [10.36.116.150]) by smtp.corp.redhat.com (Postfix) with ESMTP id 862CC8C09A; Tue, 3 Mar 2020 06:20:40 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id C061417535; Tue, 3 Mar 2020 07:20:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583216446; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=A/eOvcKb8JVz1ZcZ5FOMoLl1euHQOYoYPOIh0aBaWBY=; b=ZalNwXMJliBmThI6t/QNIKpyjI/gPBdh/Gh9U6auKr2K8DgUw+6IkwfpASNr26Q9X38idn h6UW9hlSZnkNEYVrTr09Ws/c5vk0pUnRAjKVOeSULbFIlUphvPmsLCRGGz6Ms/zg0m3/2r UgkT56cuI071rwZ+pzlc4Iwnx042+JI= X-MC-Unique: q28ttkMLOTeYZIpfM5O6dA-1 From: Gerd Hoffmann To: qemu-devel@nongnu.org Subject: [PATCH] bochs-display: add dummy mmio handler Date: Tue, 3 Mar 2020 07:20:39 +0100 Message-Id: <20200303062039.26941-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alistair Francis , Gerd Hoffmann Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The bochs-display mmio bar has some sub-regions with the actual hardware registers. What happens when the guest access something outside those regions depends on the archirecture. On x86 those reads succeed (and return 0xff I think). On risc-v qemu aborts. This patch adds handlers for the parent region, to make the wanted behavior explicit and to make things consistent across architectures. Cc: Alistair Francis Signed-off-by: Gerd Hoffmann --- hw/display/bochs-display.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/hw/display/bochs-display.c b/hw/display/bochs-display.c index 62085f9fc063..e93e838243b8 100644 --- a/hw/display/bochs-display.c +++ b/hw/display/bochs-display.c @@ -151,6 +151,26 @@ static const MemoryRegionOps bochs_display_qext_ops = =3D { .endianness =3D DEVICE_LITTLE_ENDIAN, }; =20 +static uint64_t dummy_read(void *ptr, hwaddr addr, unsigned size) +{ + return -1; +} + +static void dummy_write(void *ptr, hwaddr addr, + uint64_t val, unsigned size) +{ +} + +static const MemoryRegionOps dummy_ops =3D { + .read =3D dummy_read, + .write =3D dummy_write, + .valid.min_access_size =3D 1, + .valid.max_access_size =3D 4, + .impl.min_access_size =3D 1, + .impl.max_access_size =3D 1, + .endianness =3D DEVICE_LITTLE_ENDIAN, +}; + static int bochs_display_get_mode(BochsDisplayState *s, BochsDisplayMode *mode) { @@ -284,8 +304,8 @@ static void bochs_display_realize(PCIDevice *dev, Error= **errp) memory_region_init_io(&s->qext, obj, &bochs_display_qext_ops, s, "qemu extended regs", PCI_VGA_QEXT_SIZE); =20 - memory_region_init(&s->mmio, obj, "bochs-display-mmio", - PCI_VGA_MMIO_SIZE); + memory_region_init_io(&s->mmio, obj, &dummy_ops, NULL, + "bochs-display-mmio", PCI_VGA_MMIO_SIZE); memory_region_add_subregion(&s->mmio, PCI_VGA_BOCHS_OFFSET, &s->vbe); memory_region_add_subregion(&s->mmio, PCI_VGA_QEXT_OFFSET, &s->qext); =20 --=20 2.18.2