On Mon, Aug 22, 2022 at 03:24:53PM +0800, Qu Wenruo wrote: > > > On 2022/8/22 14:25, Greg KH wrote: > > On Mon, Aug 22, 2022 at 09:15:59AM +0800, Qu Wenruo wrote: > > > Hi, > > > > > > When backporting some btrfs specific patches to all LTS kernels, I found > > > v4.14.290 kernel unable to boot as a KVM guest with edk2-ovmf > > > (edk2-ovmf: 202205, qemu 7.0.0, libvirt 1:8.6.0). > > > > > > While all other LTS/stable branches (4.19.x, 5.4.x, 5.10.x, 5.15.x, > > > 5.18.x, 5.19.x) can boot without a hipccup. > > > > > > I tried the following configs, but none of them can even provide an > > > early output: > > > > > > - CONFIG_X86_VERBOSE_BOOTUP > > > - CONFIG_EARLY_PRINTK > > > - CONFIG_EARLY_PRINTK_EFI > > > > > > Is this a known bug or something new? > > > > Has this ever worked properly on this very old kernel tree? If so, can > > you use 'git bisect' to find the offending commit? > > Unfortunately the initial v4.14 from upstream can not even be compiled. Really? Try using an older version of gcc and you should be fine. It did build properly back in 2017 when it was released :) thanks, greg k-h