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}:$cpu" in >> + arm:arm | aarch64:aarch64 | \ >> + i386:i386 | i386:x86_64 | i386:x32 | \ >> + x86_64:i386 | x86_64:x86_64 | x86_64:x32 | \ > > IIUC, 'x86_64:i386' is claiming that you can run x86_64 > KVM guests on an i386 host. I thought that was impossible, > only 32-on-64 being allowed not 64-on-32.
You can use qemu-system-x86_64 to run i386 KVM guests, by disabling long mode with -cpu. It's not a common scenario though. >> + mips:mips | mipsel:mips | \ >> + ppc:ppc | ppcemb:ppc | ppc64:ppc | \ >> + ppc:ppc64 | ppcemb:ppc64 | ppc64:ppc64 | \ > > Same question here with ppc64:ppc suggesting you can > run 64-bit guest with KVM on a 32-bit host ? I'm not sure about this one, but right now it is allowed so this patch is not changing anything. >> + s390x:s390x) >> + return 0 >> + ;; >> + esac >> + return 1 >> +} >> + >> +supported_xen_target() { >> + test "$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. Paolo