On 08/10/17 16:54, Laszlo Ersek wrote: > 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.
Posted a patch (and CC'd you on it): https://lists.01.org/pipermail/edk2-devel/2017-August/013125.html Testing would be appreciated. Instructions are in the linked message. If you reply to edk2-devel, please subscribe first (and wait for the subscription to complete), otherwise the list will drop your email. It's bad and I've tried to change it, but so far I've failed. <https://bugzilla.tianocore.org/show_bug.cgi?id=451> Thanks Laszlo _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
