From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53328) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YgCzW-0001OM-M4 for qemu-devel@nongnu.org; Thu, 09 Apr 2015 09:59:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YgCzS-0000K0-Ch for qemu-devel@nongnu.org; Thu, 09 Apr 2015 09:59:34 -0400 Received: from mail-ig0-f182.google.com ([209.85.213.182]:36374) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YgCzS-0000Jl-5v for qemu-devel@nongnu.org; Thu, 09 Apr 2015 09:59:30 -0400 Received: by igblo3 with SMTP id lo3so67038105igb.1 for ; Thu, 09 Apr 2015 06:59:29 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150409155119.0cf5bc94@nial.brq.redhat.com> References: <1428055432-12120-1-git-send-email-zhaoshenglong@huawei.com> <1428055432-12120-11-git-send-email-zhaoshenglong@huawei.com> <877ftl1n4j.fsf@linaro.org> <20150409151718.5eb49015@nial.brq.redhat.com> <20150409155119.0cf5bc94@nial.brq.redhat.com> From: Peter Maydell Date: Thu, 9 Apr 2015 14:59:09 +0100 Message-ID: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v4 10/20] hw/arm/virt-acpi-build: Generate RSDT table List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: hangaohuai@huawei.com, "Michael S. Tsirkin" , Alexander Spyridakis , Shannon Zhao , Claudio Fontana , QEMU Developers , "Huangpeng (Peter)" , =?UTF-8?B?QWxleCBCZW5uw6ll?= , Hanjun Guo , Mark Salter , Paolo Bonzini , Laszlo Ersek , Christoffer Dall , Shannon Zhao On 9 April 2015 at 14:51, Igor Mammedov wrote: > On Thu, 9 Apr 2015 14:27:58 +0100 > Peter Maydell wrote: > >> On 9 April 2015 at 14:17, Igor Mammedov wrote: >> > On Thu, 09 Apr 2015 13:50:52 +0100 >> > Alex Benn=C3=A9e wrote: >> > >> >> >> >> Shannon Zhao writes: >> >> > + for (i =3D 0; i < table_offsets->len; ++i) { >> >> > + /* rsdt->table_offset_entry to be filled by Guest linker *= / >> >> > + bios_linker_loader_add_pointer(linker, >> >> > + ACPI_BUILD_TABLE_FILE, >> >> > + ACPI_BUILD_TABLE_FILE, >> >> > + table_data, &rsdt->table_of= fset_entry[i], >> >> > + sizeof(uint32_t)); >> >> >> >> Why are these pointers always 32 bit? Can they ever be 64 bit? >> > Laszlo, can you confirm that UEFI puts APCI tables below 4G address sp= ace? >> >> In the general case you can't guarantee that there will >> be any RAM at all below the 4G point. (The virt board >> isn't like that, obviously, but I believe there's real >> hardware out there that's designed that way.) I don't >> think we should have any 32 bit assumptions in the >> code at all -- pointer values should always be 64 bits >> everywhere. > > then that forces us to use xsdt instead of 32-bit rsdt Does that matter much? -- PMM