Re: [PATCH v3 14/16] powerpc/32: implement fast entry for syscalls on BOOKE

[Christophe Leroy]

On 05/28/2019 05:03 PM, Christophe Leroy wrote:
> Michael Ellerman <mpe@xxxxxxxxxxxxxx> a ÃcritÂ:
>
> > Christophe Leroy <christophe.leroy@xxxxxx> writes:
> > > Le 23/05/2019 Ã 09:00, Christophe Leroy a ÃcritÂ:
> > >
> > > [...]
> > >
> > > > > arch/powerpc/kernel/head_fsl_booke.o: In function `SystemCall':
> > > > > arch/powerpc/kernel/head_fsl_booke.S:416: undefined reference to
> > > > > `kvmppc_handler_BOOKE_INTERRUPT_SYSCALL_SPRN_SRR1'
> > > > > Makefile:1052: recipe for target 'vmlinux' failed
> > > > >
> > > > > > +.macro SYSCALL_ENTRY trapno intno
> > > > > > +ÂÂÂ mfsprÂÂÂ r10, SPRN_SPRG_THREAD
> > > > > > +#ifdef CONFIG_KVM_BOOKE_HV
> > > > > > +BEGIN_FTR_SECTION
> > > > > > +ÂÂÂ mtsprÂÂÂ SPRN_SPRG_WSCRATCH0, r10
> > > > > > +ÂÂÂ stwÂÂÂ r11, THREAD_NORMSAVE(0)(r10)
> > > > > > +ÂÂÂ stwÂÂÂ r13, THREAD_NORMSAVE(2)(r10)
> > > > > > +ÂÂÂ mfcrÂÂÂ r13ÂÂÂÂÂÂÂÂÂÂÂ /* save CR in r13 for nowÂÂÂÂÂÂ */
> > > > > > +ÂÂÂ mfsprÂÂÂ r11, SPRN_SRR1
> > > > > > +ÂÂÂ mtocrfÂÂÂ 0x80, r11ÂÂÂ /* check MSR[GS] without clobbering 
> > > > > > reg */
> > > > > > +ÂÂÂ bfÂÂÂ 3, 1975f
> > > > > > +ÂÂÂ bÂÂÂ kvmppc_handler_BOOKE_INTERRUPT_\intno\()_SPRN_SRR1
> > > > >
> > > > > It seems to me that the "_SPRN_SRR1" on the end of this line
> > > > > isn't meant to be there... However, it still fails to link with that
> > > > > removed.
> > >
> > > It looks like I missed the macro expansion.
> > >
> > > The called function should be kvmppc_handler_8_0x01B
> > >
> > > Seems like kisskb doesn't build any config like this.
> >
> > I thought we did, ie:
> >
> > http://kisskb.ellerman.id.au/kisskb/buildresult/13817941/
>
> That's a ppc64 config it seems. The problem was on booke32.
>
> Christophe
>
> > But clearly something is missing to trigger the bug.

I was able to trigger the bug with mpc85xx_defconfig + 
CONFIG_VIRTUALIZATION + CONFIG_PPC_E500MC

The bug pops up when CONFIG_KVM_BOOKE_HV is set.

Christophe

> > cheers