On 08/10/17 14:15, Laszlo Ersek wrote: > So I think it comes down to another toolchain difference between RHEL-7 > and Fedora-26. Likely gcc -- the commit you identified is also related > to a C compiler. In particular: > > - on RHEL-7, the system compiler (gcc-4.8.5) is mapped to the "GCC48" > toolchain settings of edk2, which lack support for LTO (link time > optimization), > > - in the Fedora package's SPEC file, the "GCC49" toolchain settings are > selected for the build in a fixed manner, which also lack support for > LTO, > > - in kraxel's SPEC file, Fedora-26's gcc-7 compiler is mapped to the > "GCC5" toolchain settings, which *enable* LTO (for DEBUG). > > The test you suggested to David elsewhere in this thread confirms that > the Fedora -- well, "virt-preview" -- package, built with GCC49 > settings, works, and that Gerd's package, built with GCC5 settings, > breaks. > > I'll spin up a Fedora-26 guest and build OVMF there.
I confirm that building with gcc-7.1.1 on Fedora-26, using the GCC5 toolchain settings and the DEBUG target (= optimizations enabled), the problem reproduces for me. Keeping everything the same except switching DEBUG to NOOPT (= optimizations disabled) the OVMF binary returns to working state. So, OVMF is being mis-built / mis-optimized by gcc-7.1, with the DEBUG GCC5 settings. I'll try to tweak both the code and the gcc flags. Thanks Laszlo _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
