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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 23/09/26 07:13, Shrikanth Hegde wrote: > > > On 9/23/26 10:39 AM, Christian Zigotzky wrote: >> On 21/09/26 07:12, Shrikanth Hegde wrote: >>> Hi Christian. >>> >>> On 9/20/26 6:34 PM, Christian Zigotzky wrote: >>>> On 09/20/2026 01:49 PM, Christian Zigotzky wrote: >>>>> On 09/18/2026 09:10 AM, Michal Suchánek wrote: >>>>>> On Fri, Sep 18, 2026 at 04:39:57AM +0200, Christian Zigotzky wrote: >>>>>>> On 17/09/26 16:15, Shrikanth Hegde wrote: >>>>>>>> Hi Michal, >>>>>>>> >>>>>>>>>> Give it a try. >>>>>>>>>> >>>>>>>>>> I am suspecting both lockup, stack corruptions are secondary >>>>>>>>>> symptoms here. >>>>>>>>>> While recreate, I have different type of traces. >>>>>>>>> Yes, it does work for the crash I see. >>>>>>>> Thanks. Give me sometime to see further on that. Didn't get any >>>>>>>> time >>>>>>>> today. >>>>>>>> >>>>>>>>> However, we hijacked the report >>>>>>>>> of KVM locking up on FSL Cyrus+, and that is likely a >>>>>>>>> different problem >>>>>>>>> still not addressed. >>>>>>>>> >>>>>>>> Ah, that's what you meant. Yes, i still don't know where FSL >>>>>>>> Cyrus+ is >>>>>>>> stuck. >>>>>>>> >>>>>>>> I would need help from FSL Cyrus+ to get some logs or is there >>>>>>>> a way we >>>>>>>> can spin of >>>>>>>> a QEMU guest of it? We should have the log to start somewhere. >>>>>>>> >>>>>>>> >>>>>>> It's difficult to get a log because it freezes and can't write >>>>>>> any error >>>>>>> messages to the log files. This bug is very old. We had this >>>>>>> issue some >>>>>>> years ago but we was able to disable PREEMPT because we don't >>>>>>> need it. >>>>>> I would expect serial console and sysrq could give something, >>>>>> depending >>>>>> on how much of the kernel is frozen. >>>>>> >>>>>> Thanks >>>>>> >>>>>> Michal >>>>> Here is a serial log: >>>>> https://github.com/user-attachments/files/32433586/e5500_preempt_putty.log >>>>> >>> >>> Thanks Michal for helping to get the traces. >>> >>>> Another serial log with pcie_ports=compat: >>>> https://github.com/user-attachments/files/32434487/e5500_preempt_pcie_ports_compat_putty.log >>>> >>> >>> I see it is mostly busy with printing >>> WARNING: at .enable_kernel_fp+0x30/0x78, CPU#3: qemu-system-ppc/4884 >>> >>> The path seems to be same also. >>> >>> [c000000085ca7700] [c00000000005de84] .kvmppc_load_guest_fp+0x30/0x80 >>> [c000000085ca7780] [c00000000005f2a0] .kvmppc_handle_exit+0x5bc/0x5cc >>> [c000000085ca7830] [c00000000006204c] .kvmppc_resume_host+0xb8/0x10c >>> >>> >>> Does below help to boot or make it stable? >>> --- >>>  arch/powerpc/kvm/booke.c | 9 ++++++++- >>>  1 file changed, 8 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c >>> index 13ad4cf5fa71..d4be7a306bfc 100644 >>> --- a/arch/powerpc/kvm/booke.c >>> +++ b/arch/powerpc/kvm/booke.c >>> @@ -1404,10 +1404,17 @@ int kvmppc_handle_exit(struct kvm_vcpu >>> *vcpu, unsigned int exit_nr) >>>          if (s <= 0) >>>              r = (s << 2) | RESUME_HOST | (r & RESUME_FLAG_NV); >>>          else { >>> -            /* interrupts now hard-disabled */ >>> +            /* >>> +             * interrupts now hard-disabled. i.e EE=0 >>> +             * But irqs_disabled relies on PACA entries >>> +             * and fixup below enables it. >>> +             * So irqs_disabled == false >>> +             */ >>>              kvmppc_fix_ee_before_entry(); >>> +            preempt_disable(); >>>              kvmppc_load_guest_fp(vcpu); >>>              kvmppc_load_guest_altivec(vcpu); >>> +            preempt_enable_no_resched(); >>>          } >>>      } >>> >>> >> Hi, >> >> Thanks a lot for your patch! >> >> I patched the 7.3-rc4 kernel sources with your new patch and compiled >> the kernel again yesterday. [1] >> > > Thanks for trying. > >> Unfortunately, the issue still exists. >> > > Can you share the console log of the kernel with the patch applied? > We need to see where it is stuck now. Has it made forward progress? > >> I tested it with a guest kernel with and without preempt support. >> >> Cheers, >> Christian >> >> [1] >> https://github.com/chzigotzky/kernels/releases/tag/v7.3.0-rc4-2-preempt >> > Here is a new serial log from the patched kernel: https://github.com/user-attachments/files/32570808/e5500_preempt_pcie_ports_compat_patched_putty.log Thanks -- Sent with BrassMonkey 34.3.2.1 (https://github.com/chzigotzky/Web-Browsers-and-Suites-for-Linux-PPC/releases/tag/BrassMonkey_34.3.2.1)