Re: [Qemu-devel] 3.1.0-rc{0,1} doesn't start

[balducci@units.it]

hi

thanks for taking the time to reply

Dr. David Alan Gilbert writes:
> > I suspect that this might be some problem on my side, as I couldn't
> > find any similar report (apart some old (qemu-2.8.50) threads, that
> > didn't help)
>
> Not necessarily; can you tell me:
>   a) At what point does it fail - immediately when booting the guest?
>      Some time during the boot? Later?
>   b) What guest does it happen on?

a) the error happens almost immediately; I mean: when I run qemu from an
   xterm, it doesn't even popup its window: it just dumps the error
   message to the terminal and stops
b) the guest is an old windows XP OS; but, as I say above, all goes as
   if qemu doesn't even load the OS image (at least this is my
   impression)

Meantime, I have tried to (quick&dirty) disable the error
catching/asserting in i386/kvm.c:

install:41> diff ./qemu-3.1.0-rc1/target/i386/kvm.c.MSR_HACK ./qemu-3.1.0-rc1/target/i386/kvm.c
2205c2205
<     if (ret < cpu->kvm_msr_buf->nmsrs) {
---
>     if (1==0) {
2211c2211
<     assert(ret == cpu->kvm_msr_buf->nmsrs);
---
>     assert(1==1);
2524c2524
<     if (ret < cpu->kvm_msr_buf->nmsrs) {
---
>     if (1==0) {
2530c2530
<     assert(ret == cpu->kvm_msr_buf->nmsrs);
---
>     assert(1==1);

and that makes qemu start and work without apparent problems.
Of course, that is a crude and risky (I guess) workaround...

thanks again

ciao
-gabriele