From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40340) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V6IZe-00086u-EN for qemu-devel@nongnu.org; Mon, 05 Aug 2013 07:03:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V6IZV-0003Uu-Tg for qemu-devel@nongnu.org; Mon, 05 Aug 2013 07:03:38 -0400 Received: from mout.web.de ([212.227.15.3]:59386) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V6IZV-0003Uh-KF for qemu-devel@nongnu.org; Mon, 05 Aug 2013 07:03:29 -0400 Received: from mchn199C.mchp.siemens.de ([95.157.58.223]) by smtp.web.de (mrweb102) with ESMTPSA (Nemesis) id 0MLPNm-1V5kL73PZy-000dql for ; Mon, 05 Aug 2013 13:03:28 +0200 Message-ID: <51FF867E.6070906@web.de> Date: Mon, 05 Aug 2013 13:03:26 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <51FCBFCD.5020608@web.de> <51FF71BD.5040400@suse.de> <51FF7ED6.3050101@web.de> <51FF8211.3050509@web.de> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="W5OlcMpLj21HWQpLqk6w2WHwQ0iR0vf4x" Subject: Re: [Qemu-devel] [PATCH 1/2] memory: Provide separate handling of unassigned io ports accesses List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Paolo Bonzini , =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= , Aurelien Jarno , qemu-devel This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --W5OlcMpLj21HWQpLqk6w2WHwQ0iR0vf4x Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 2013-08-05 12:51, Peter Maydell wrote: > On 5 August 2013 11:44, Jan Kiszka wrote: >> On 2013-08-05 12:36, Peter Maydell wrote: >>> On 5 August 2013 11:30, Jan Kiszka wrote: >>>> On 2013-08-05 11:59, Peter Maydell wrote: >>>>> Or do you mean that if we had: >>>>> >>>>> [ system memory region, with its own default read/write ops ] >>>> >>>> I cannot imagine how this could work. The system memory region has n= o >>>> clue about what the regions below it can handle and what not. So it = has >>>> to pass through the io window. >>> >>> The system memory region's just a container, you can add a >>> background region to it at lowest-possible-priority, which >>> then takes accesses which are either (a) not in any subregion >>> or (b) in a subregion but that container doesn't specify >>> its own io ops and nothing in that container handles the >>> access. (Or you could create the system memory region with >>> its own IO ops, which would have the same effect.) >> >> First, we do not render MMIO and IO within the same address space so >> far. >=20 > Is this a statement made because you've checked all the boards > and know that nobody's mapping the system-io memory region into > the system-memory region? (It is technically trivial, you > just need to call memory_region_add_subregion() directly > or indirectly...) I know this because I just recently wrote the patch that enables this trivial step, i.e. converted PIO dispatching to the memory subsystem. Jan --W5OlcMpLj21HWQpLqk6w2WHwQ0iR0vf4x Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlH/hn4ACgkQitSsb3rl5xRXywCfXOx8gscbzteVoNQisM6k8PZ0 LQwAoMibpz6mmSZpUVc/kIrtIFAsxBeQ =CFfg -----END PGP SIGNATURE----- --W5OlcMpLj21HWQpLqk6w2WHwQ0iR0vf4x--