From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Kc9q0-00059G-9A for qemu-devel@nongnu.org; Sat, 06 Sep 2008 22:17:16 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Kc9px-00057x-TI for qemu-devel@nongnu.org; Sat, 06 Sep 2008 22:17:15 -0400 Received: from [199.232.76.173] (port=38485 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Kc9px-00057u-Ms for qemu-devel@nongnu.org; Sat, 06 Sep 2008 22:17:13 -0400 Received: from an-out-0708.google.com ([209.85.132.249]:50743) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Kc9px-000874-3O for qemu-devel@nongnu.org; Sat, 06 Sep 2008 22:17:13 -0400 Received: by an-out-0708.google.com with SMTP id d18so162655and.130 for ; Sat, 06 Sep 2008 19:17:12 -0700 (PDT) Message-ID: <48C33977.8070206@codemonkey.ws> Date: Sat, 06 Sep 2008 21:16:23 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Bug with TARGET_PHYS_ADDR_SPACE_BITS References: <48AB070A.1040104@redhat.com> <20080820061558.GB17273@volta.aurel32.net> <48AD801D.5090308@redhat.com> In-Reply-To: <48AD801D.5090308@redhat.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Chris Lalancette wrote: > Aurelien Jarno wrote: > >> On Tue, Aug 19, 2008 at 07:46:50PM +0200, Chris Lalancette wrote: >> >>> Hello, >>> oVirt is currently using straight x86_64 qemu emulation for certain parts >>> of the architecture (we mostly use KVM, but need to use full emulation for a >>> couple of parts). We recently upgraded our userspace package to kvm-72, but >>> found that we could not PXE boot guests when we were doing full emulation (under >>> kvm, we could PXE boot just fine). We also tried using qemu SVN tip, with >>> similar results. We ended up doing a bisect, and tracked down the problem to >>> this commit (from the kvm repo, but pulled from qemu): >>> >>> http://git.kernel.org/?p=linux/kernel/git/amit/kvm-userspace.git;a=commit;h=468f7507339a5236bff8ab339eb0c1b019a95fda >>> >>> The important changes in there in terms of this bug revolves around >>> TARGET_PHYS_ADDR_SPACE_BITS in exec.c. If I change that back to 32 (what it was >>> before this patch for x86_64), the PXE boot succeeds. Also, if I remove >>> TARGET_PHYS_ADDR_SPACE_BITS > 32 conditional code in phys_page_find_alloc(), but >>> leave TARGET_PHYS_ADDR_SPACE_BITS as 42, the PXE boot also works. I can't claim >>> to understand the conditional code I've compiled out, so I'm not sure where the >>> bug would be. Does anyone have an idea what the problem might be? >>> >>> > > Sorry for the delay in responding. > > >> Are you using qemu or qemu-system-x86_64? Could you also build qemu with >> --disable-kqemu? It possible that kqemu support is causing this problem, >> as it is limited to 32 bits. >> > > I'm not sure what the difference between qemu and qemu-system-x86_64 is. Can > you explain? I've been testing with qemu-system-x86_64, for what it's worth. > qemu is really qemu-system-i386 just unfortunately named. This define will differ in the qemu vs qemu-system-x86_64 binaries. Has there been any resolution here? Regards, Anthony Liguori