From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40127) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dSKTO-00072Q-6V for qemu-devel@nongnu.org; Tue, 04 Jul 2017 05:50:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dSKTL-000757-36 for qemu-devel@nongnu.org; Tue, 04 Jul 2017 05:50:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57436) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dSKTK-00074j-Pa for qemu-devel@nongnu.org; Tue, 04 Jul 2017 05:50:19 -0400 Date: Tue, 4 Jul 2017 10:50:12 +0100 From: "Daniel P. Berrange" Message-ID: <20170704095012.GG3135@redhat.com> Reply-To: "Daniel P. Berrange" References: <1499099693-22903-1-git-send-email-pbonzini@redhat.com> <1499099693-22903-2-git-send-email-pbonzini@redhat.com> <20170704082805.GA3135@redhat.com> <384f451b-70c6-a6c3-5b90-e87b79aada27@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <384f451b-70c6-a6c3-5b90-e87b79aada27@redhat.com> Subject: Re: [Qemu-devel] [PATCH 01/22] configure: factor out list of supported Xen/KVM/HAX targets List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, rth@twiddle.net, thuth@redhat.com, anthony.xu@intel.com, a.rigo@virtualopensystems.com, yang.zhong@intel.com On Tue, Jul 04, 2017 at 11:44:41AM +0200, Paolo Bonzini wrote: > > > On 04/07/2017 10:28, Daniel P. Berrange wrote: > >> +supported_kvm_target() { > >> + test "$kvm" = "yes" || return 1 > >> + glob "$1" "*-softmmu" || return 1 > >> + case "${1%-softmmu}:$cpu" in > >> + arm:arm | aarch64:aarch64 | \ > >> + i386:i386 | i386:x86_64 | i386:x32 | \ > >> + x86_64:i386 | x86_64:x86_64 | x86_64:x32 | \ > > > > IIUC, 'x86_64:i386' is claiming that you can run x86_64 > > KVM guests on an i386 host. I thought that was impossible, > > only 32-on-64 being allowed not 64-on-32. > > You can use qemu-system-x86_64 to run i386 KVM guests, by disabling long > mode with -cpu. It's not a common scenario though. Wow, obscure :-) > > >> + mips:mips | mipsel:mips | \ > >> + ppc:ppc | ppcemb:ppc | ppc64:ppc | \ > >> + ppc:ppc64 | ppcemb:ppc64 | ppc64:ppc64 | \ > > > > Same question here with ppc64:ppc suggesting you can > > run 64-bit guest with KVM on a 32-bit host ? > > I'm not sure about this one, but right now it is allowed so this patch > is not changing anything. > > >> + s390x:s390x) > >> + return 0 > >> + ;; > >> + esac > >> + return 1 > >> +} > >> + > >> +supported_xen_target() { > >> + test "$xen" = "yes" || return 1 > >> + glob "$1" "*-softmmu" || return 1 > >> + case "${1%-softmmu}:$cpu" in > >> + arm:arm | aarch64:aarch64 | \ > >> + i386:i386 | i386:x86_64 | x86_64:i386 | x86_64:x86_64) > > This again is claiming support for 64-bit guests with Xen on a > > 32-bit host, which AFAIK is impossible. > > 32-bit dom0 with 64-bit guests actually is not only possible, but also > widely used. Oh, i guess I'm missing the distinction between 64-bit hypervisor vs 32-bit dom-0, which still lets you use 64-bit dom-U. In that case, Reviewed-by: Daniel P. Berrange Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|