On Wed, 23 Aug 2017 11:05:59 +0200 Christian Borntraeger <borntrae...@de.ibm.com> wrote:
> On 08/23/2017 10:39 AM, Cornelia Huck wrote: > > On Wed, 23 Aug 2017 10:16:27 +0200 > > Paolo Bonzini <pbonz...@redhat.com> wrote: > > > >> On 23/08/2017 10:06, Thomas Huth wrote: > >>> On 23.08.2017 10:00, David Hildenbrand wrote: > >>>> On 23.08.2017 08:53, Christian Borntraeger wrote: > > > >>>>> @@ -6522,6 +6527,20 @@ if test "$target_linux_user" = "yes" -o > >>>>> "$target_bsd_user" = "yes" ; then > >>>>> ldflags="$ldflags $textseg_ldflags" > >>>>> fi > >>>>> > >>>>> +# Newer kernels on s390 check for an S390_PGSTE program header and > >>>>> +# enable the pgste page table extensions in that case. This makes > >>>>> +# the vm.allocate_pgste sysctl unnecessary. We enable this program > >>>>> +# header if > >>>>> +# - we build on s390x > >>>>> +# - we build the system emulation for s390x (qemu-system-s390x) > >>>>> +# - KVM is enabled > >>>>> +# - the linker support --s390-pgste > >>>>> +if test "$TARGET_ARCH" = "s390x" -a "$target_softmmu" = "yes" -a > >>>>> "$ARCH" = "s390x" -a "$kvm" = "yes"; then > >>>> > >>>> Wonder if the "$ARCH" check is really necessary: TARGET_ARCH=s390x with > >>>> kvm=yes should only build on s390x. > >>> > >>> Isn't kvm=yes and TARGET_ARCH=s390x also possible on a x86 host, where > >>> only the x86_64 target is built with CONFIG_KVM=y, but the s390x target > >>> with CONFIG_KVM=n ? > >> > >> Yes. You could use > >> > >> if test "$ARCH" = "s390x" && supported_kvm_target $target; then > >> ... > >> fi > >> > >> Or, in the existing "if supported_kvm_target $target" conditional, add > >> > >> if test "$ARCH" = s390x && ld_has --s390-pgste; then > >> ... > >> fi > > > > That conditional is unfortunately before the setup of ldflags; but I > > like the idea of using supported_kvm_target. > > This is now bike-shedding, no? :-) > I think I prefer to write out the the single statements as is. > I would need to test for supported_kvm_target AND s390 anyway, to prevent > checking ld on x86 as well. I prefer the shorter variant, but I don't mind the exploded one either. > > So unless there are complains, I will provide a v3 with the typo fixed. Fine with me as well.
