On Sat, 2018-05-26 at 20:45 -0700, Guenter Roeck wrote:
>
> I already have a patch, or at least one that does the trick for me.
> Getting qemu patched was not the problem. I just want to be sure that
> the problem is indeed a qemu problem.
Hey Guenter !
It's not quite the right patch though. The PCR is a hypervisor
priviledged register, your patch makes it supervisor accessible.
I don't have all my stuff at hand to provide a "proper" or tested patch
but it should look like
spr_register_hv(env, SPR_PCR, "PCR",
SPR_NOACCESS, SPR_NOACCESS,
SPR_NOACCESS, SPR_NOACCESS,
&spr_read_generic, &spr_write_generic, 0);
Additionally the TCG ppc instruction decoder should be made to check
the PCR for varous instructions (that or use a specific write callback
that affects the CPU flags) but that's less urgent.
Cheers,
Ben.
> Thanks,
> Guenter
>
> ---
> > From 1617bac264b4c49d817b6947611affa9b73318f6 Mon Sep 17 00:00:00 2001
>
> From: Guenter Roeck <li...@roeck-us.net>
> Date: Fri, 25 May 2018 06:38:40 -0700
> Subject: [PATCH] PowerPC: Permit privileged access to SPR_PCR for POWER7+
>
> Without this access, Linux mainline bails out.
>
> Signed-off-by: Guenter Roeck <li...@roeck-us.net>
> ---
> target/ppc/translate_init.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> index 391b94b..3b09c49 100644
> --- a/target/ppc/translate_init.c
> +++ b/target/ppc/translate_init.c
> @@ -7953,11 +7953,12 @@ static void gen_spr_power6_common(CPUPPCState *env)
> #endif
> /*
> * Register PCR to report POWERPC_EXCP_PRIV_REG instead of
> - * POWERPC_EXCP_INVAL_SPR.
> + * POWERPC_EXCP_INVAL_SPR in userspace. Permit privileged
> + * access.
> */
> spr_register(env, SPR_PCR, "PCR",
> SPR_NOACCESS, SPR_NOACCESS,
> - SPR_NOACCESS, SPR_NOACCESS,
> + &spr_read_generic, &spr_write_generic,
> 0x00000000);
> }
>
