пн, 15 июн. 2026 г., 16:33 BALATON Zoltan <[email protected]>:

> On Mon, 15 Jun 2026, Andrew Randrianasulu wrote:
> > I also tried to see "info registers" as you showed in another email from
> > 2021 where you tried to use kvm-pr on qemu-emulated G5 and it showed
> >
> > info registers
> >                NIP 0000000000000700   LR 0000000000000000 CTR
> > 0000000000000000 XER 0000000000000000 CPU#0
> > MSR 8000000000000000 HID0 0000000060000000  HF 8000000000000000 iidx 3
> didx
> > 3                      TB 00000000 00000000 DECR 0
> >                                              GPR00 0000000000000000
> > 0000000000000000 0000000000000000 0000000000000000
> > GPR04 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> >                        GPR08 0000000000000000 0000000000000000
> > 0000000000000000 0000000000000000                          GPR12
> > 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> > GPR16 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> >                        GPR20 0000000000000000 0000000000000000
> > 0000000000000000 0000000000000000                          GPR24
> > 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> >                  GPR28 0000000000000000 0000000000000000 0000000000000000
> > 0000000000000000
> > CR 00000000  [ -  -  -  -  -  -  -  -  ]             RES ffffffffffffffff
> >                        FPR00 0000000000000000 0000000000000000
> > 0000000000000000 0000000000000000                          FPR04
> > 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> >                  FPR08 0000000000000000 0000000000000000 0000000000000000
> > 0000000000000000
> > FPR12 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> >                        FPR16 0000000000000000 0000000000000000
> > 0000000000000000 0000000000000000                          FPR20
> > 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> >                  FPR24 0000000000000000 0000000000000000 0000000000000000
> > 0000000000000000                          FPR28 0000000000000000
> > 0000000000000000 0000000000000000 0000000000000000
> > FPSCR 0000000000000000
> >                        SRR0 0000000000000100  SRR1 8000000000080000
> PVR
> > 00000000003c0301 VRSAVE 0000000000000000      SPRG0 0000000000000000
> SPRG1
> > 0000000000000000  SPRG2 0000000000000000  SPRG3 0000000000000000
> SPRG4
> > 0000000000000000 SPRG5 0000000000000000  SPRG6 0000000000000000  SPRG7
> > 0000000000000000
> > SDR1 0000000000000000   DAR 0000000000000000  DSISR 0000000000000000
> >
> > (qemu) q
> >
> > not sure if instruction pointer moved or not ...
> >
> > looking at some scroll buffer in Termux (I ssh into powermac ) it was at
> > 700 all 3 times I typed "info registers" into qemu monitor.
> >
> > but this debug msg
> >
> > [154992.595845] Couldn't emulate instruction 0x00000000 (op 0 xop 0)
> > [154992.595859] kvmppc_exit_pr_progint: emulation at 100 failed
> (00000000)
> >
> >
> > fills logs FAST!
>
> NIP=0x700 is illegal instruction exception due to trying to execute 0
> opcode at 0x100 which is the reset vector but shouldn't it try to start at
> 0xfff00100? Maybe there's some issue with setting up KVM correctly? You
> can trace what is executed in TCG with -d in_asm but that does not work
> for KVM as it's a TCG debug option. I don't know how to trace execution
> with KVM but probably there are some trace points for that. Maybe you get
> some info with -trace enable="kvm*" but I don't know how to understand
> that output.
>

-trace *kvm* (on qemu 6.1.1) ends with

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8080

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8080

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8080

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8080
kvm_vcpu_ioctl cpu_index 0, type 0x84d0ae84, arg 0xe81a7b78

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8018

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8018
kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8018

kvm_vcpu_ioctl cpu_index 0, type 0x8010aeac, arg 0xe81a8018
kvm_failed_spr_set Warning: Unable to set SPR 1013 to KVM: Invalid
argument
kvm_vcpu_ioctl cpu_index 0, type 0x2000ae80, arg (nil)

kvm_vcpu_ioctl cpu_index 0, type 0x2000ae80, arg (nil)

My hack idea  about adding || defined CONFIG_PPC_BOOK3S_64 to two statement
in

arch/powerpc/kvm/emulate.c

also did not improve situation :(

but at least I know I am running with patched kvm_pr module because I
commented this kernel printk about "failed to emulate instruction" and this
line disappeared from dmesg.




> Regards,
> BALATON Zoltan
>

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