Re: kexec reboot failed due to commit 75d090fd167ac

From: Kirill A. Shutemov
Date: Tue Aug 29 2023 - 09:01:47 EST


On Tue, Aug 29, 2023 at 08:51:34PM +0800, Aaron Lu wrote:
> On Tue, Aug 29, 2023 at 07:14:59PM +0700, Bagas Sanjaya wrote:
> > On Tue, Aug 29, 2023 at 07:48:16PM +0800, Aaron Lu wrote:
> > > Hi Kirill,
> > >
> > > Ever since v6.5-rc1, I found that I can not use kexec to reboot an Intel
> > > SPR test machine. With git bisect, the first bad commit is 75d090fd167ac
> > > ("x86/tdx: Add unaccepted memory support").
> > >
> > > I have no idea why a tdx change would affect it, I'm not doing anything
> > > related to tdx.
> > >
> > > Any ideas?

Are we talking about bare metal? Or is it kexec in a VM?

> > > The kernel config is attached, let me know if you need any other info.
> >
> > Can you provide system logs (e.g. journalctl output) when attempting to
> > reboot?
>
> ... ...
> Aug 29 19:15:59 be3af2b6059f systemd-shutdown[1]: Syncing filesystems and block devices.
> Aug 29 19:15:59 be3af2b6059f systemd-shutdown[1]: Sending SIGTERM to remaining processes...
> Aug 29 19:16:00 be3af2b6059f systemd-journald[2629]: Journal stopped
> -- Boot 7e5173842b8b4be581886ff25ad0c02f --
> Aug 29 19:24:27 be3af2b6059f kernel: microcode: updated early: 0x2b000161 -> 0x2b000461, date = 2023-03-13
> Aug 29 19:24:27 be3af2b6059f kernel: Linux version 6.3.8-100.fc37.x86_64 (mockbuild@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)
> Aug 29 19:24:27 be3af2b6059f kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-6.3.8-100.fc37.x86_64 root=UUID=4381321e-e0>
>
> First 3 lines are from the first kernel, then I attmpted to kexec reboot
> to 6.4.0-rc5-00009-g75d090fd167a and remote console hanged with the
> reboot message of the first kernel. After a while, I know kexec failed
> so I power cycled the machine to boot into a distro kernel, that is the
> last 3 lines. There is no trace of the failed boot.
>
> I guess the kexeced kernel failed to start early in the boot process
> so the log is probably only available in serial, if any. Unfortunately,
> there is no serial support for this machine.

Could you show dmesg of the first kernel before kexec?

--
Kiryl Shutsemau / Kirill A. Shutemov