From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58349) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VlKpT-00054d-Ui for qemu-devel@nongnu.org; Tue, 26 Nov 2013 10:45:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VlKpN-0006Wh-8c for qemu-devel@nongnu.org; Tue, 26 Nov 2013 10:45:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34451) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VlKpM-0006Wd-WB for qemu-devel@nongnu.org; Tue, 26 Nov 2013 10:45:29 -0500 Date: Tue, 26 Nov 2013 17:48:40 +0200 From: "Michael S. Tsirkin" Message-ID: <20131126154840.GA22903@redhat.com> References: <1384775449-6693-1-git-send-email-mst@redhat.com> <1384775449-6693-2-git-send-email-mst@redhat.com> <52945802.2010309@redhat.com> <20131126091014.GA18777@redhat.com> <1385463651.10163.10.camel@nilsson.home.kraxel.org> <20131126140455.GD21803@redhat.com> <5294AEA4.7030308@redhat.com> <1385480536.10163.28.camel@nilsson.home.kraxel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1385480536.10163.28.camel@nilsson.home.kraxel.org> Subject: Re: [Qemu-devel] [PULL for-1.8 1/2] pc: disable pci-info List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: Eduardo Habkost , "Jordan Justen (Intel address)" , qemu-devel@nongnu.org, Anthony Liguori , Igor Mammedov , Laszlo Ersek On Tue, Nov 26, 2013 at 04:42:16PM +0100, Gerd Hoffmann wrote: > Hi, > > > This doesn't clamp the w32.begin value into [0x80000000, 0xe0000000], > > which seems wrong. > > Why? In a 1G guest you can map pci bars at 0x40000000 just fine. > > _CRS in acpi should declare the area where you can map pci bars, and > that happens to be end-of-ram -> ioapci base. > > Firmware can choose to use a smaller area. Both seabios and ovmf will > not map anyting below 0x80000000. That is just fine. As long as all > pci bars get mapped inside the region declared in _CRS things will work. > > While thinking about it: There is one possible reason to not do it: > Guest bugs. IIRC windows doesn't like the 64bit pci window being larger > than 2G. > Possibly that is an issue with the 32bit window too. If that > is the case we should indeed not use w32.begin values smaller than > 0x8000000. Igor, any clue? I think the issues are all around 64 bit. It's not hard to test. > > Guys, I'm confused and annoyed out of my brains by the divergence here. > > In my perception Michael, Igor, and Gerd are all proposing different > > things, and my ideas are either rejected or ignored (even though they > > occasionally overlap with ideas from others). > > Hmm, as far as I can see there is an agreement that it is qemu's fault, > the acpi tables need fixing, and ovmf should not need changes any > changes. > > Mimicing seabios/qemu logic in ovmf can be used as temporary stopgap > while details are sorted on the qemu side. > > cheers, > Gerd >