From nobody Fri Nov 7 02:17:59 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; 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 208.118.235.17 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 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1545162667836213.56099103190422; Tue, 18 Dec 2018 11:51:07 -0800 (PST) Received: from localhost ([::1]:54865 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZI7z-0005dV-MS for importer@patchew.org; Tue, 18 Dec 2018 11:21:51 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54757) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZI00-0007Ls-G7 for qemu-devel@nongnu.org; Tue, 18 Dec 2018 11:13:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZHzy-0003Hd-PB for qemu-devel@nongnu.org; Tue, 18 Dec 2018 11:13:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48118) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gZHzw-0003An-Hb for qemu-devel@nongnu.org; Tue, 18 Dec 2018 11:13:32 -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 mx1.redhat.com (Postfix) with ESMTPS id 13F5885541; Tue, 18 Dec 2018 16:13:28 +0000 (UTC) Received: from redhat.com (ovpn-120-67.rdu2.redhat.com [10.10.120.67]) by smtp.corp.redhat.com (Postfix) with SMTP id 022D66012C; Tue, 18 Dec 2018 16:13:26 +0000 (UTC) Date: Tue, 18 Dec 2018 11:13:26 -0500 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20181218161008.3882-25-mst@redhat.com> References: <20181218161008.3882-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181218161008.3882-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 18 Dec 2018 16:13:28 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v2 24/30] hw: i386: Use correct RSDT length for checksum 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: Peter Maydell , Samuel Ortiz , Eduardo Habkost , Igor Mammedov , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Igor Mammedov AcpiRsdpDescriptor describes revision 2 RSDP table so using sizeof(*rsdp) for checksum calculation isn't correct since we are adding extra 16 bytes. But acpi_data_push() zeroes out table, so just by luck we are summing up exta zeros which still yelds correct checksum. Fix it up by explicitly stating table size instead of using pointer arithmetics on stucture. PS: Extra 16 bytes are still wasted, but droping them will break migration for machines older than 2.3 due to size mismatch, for 2.3 and older it's not an issue since they are using resizable memory regions (a1666142d) for ACPI blobs. So keep wasting memory to avoid breaking old machines. Fixes: 72c194f7e (i386: ACPI table generation code from seabios) Signed-off-by: Igor Mammedov Reviewed-by: Samuel Ortiz Signed-off-by: Samuel Ortiz Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/acpi-build.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 35f17d0d91..fb877648ac 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2550,6 +2550,11 @@ build_amd_iommu(GArray *table_data, BIOSLinker *link= er) static void build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned rsdt_tbl_offse= t) { + /* AcpiRsdpDescriptor describes revision 2 RSDP table and as result we + * allocate extra 16 bytes for pc/q35 RSDP rev1 as well. Keep extra 16= bytes + * wasted to make sure we won't breake migration for machine types old= er + * than 2.3 due to size mismatch. + */ AcpiRsdpDescriptor *rsdp =3D acpi_data_push(rsdp_table, sizeof *rsdp); unsigned rsdt_pa_size =3D sizeof(rsdp->rsdt_physical_address); unsigned rsdt_pa_offset =3D @@ -2567,7 +2572,7 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, un= signed rsdt_tbl_offset) =20 /* Checksum to be filled by Guest linker */ bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE, - (char *)rsdp - rsdp_table->data, sizeof *rsdp, + (char *)rsdp - rsdp_table->data, 20 /* ACPI rev 1.0 RSDP size */, (char *)&rsdp->checksum - rsdp_table->data); } =20 --=20 MST