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References: <20200717040958.70561-1-ravi.bangoria@linux.ibm.com> <20200717040958.70561-5-ravi.bangoria@linux.ibm.com>
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From:   Jordan Niethe <jniethe5@gmail.com>
Date:   Fri, 17 Jul 2020 14:23:03 +1000
Message-ID: <CACzsE9py0x7wFyG-FgjK-cF8L02OQyOKbqDzP6agFt-Dxc4ejg@mail.gmail.com>
Subject: Re: [PATCH v4 04/10] powerpc/watchpoint: Enable watchpoint
 functionality on power10 guest
To:     Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc:     Michael Ellerman <mpe@ellerman.id.au>, mikey@neuling.org,
        apopple@linux.ibm.com, Paul Mackerras <paulus@samba.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Christophe Leroy <christophe.leroy@c-s.fr>,
        naveen.n.rao@linux.vnet.ibm.com, peterz@infradead.org,
        jolsa@kernel.org, oleg@redhat.com, fweisbec@gmail.com,
        mingo@kernel.org, pedromfc@br.ibm.com, miltonm@us.ibm.com,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
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On Fri, Jul 17, 2020 at 2:10 PM Ravi Bangoria
<ravi.bangoria@linux.ibm.com> wrote:
>
> CPU_FTR_DAWR is by default enabled for host via CPU_FTRS_DT_CPU_BASE
> (controlled by CONFIG_PPC_DT_CPU_FTRS). But cpu-features device-tree
> node is not PAPR compatible and thus not yet used by kvm or pHyp
> guests. Enable watchpoint functionality on power10 guest (both kvm
> and powervm) by adding CPU_FTR_DAWR to CPU_FTRS_POWER10. Note that
> this change does not enable 2nd DAWR support.
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
I ran the ptrace-hwbreak selftest successfully within a power10 kvm guest.
Tested-by: Jordan Niethe <jniethe5@gmail.com>
> ---
>  arch/powerpc/include/asm/cputable.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> index bac2252c839e..e506d429b1af 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -478,7 +478,7 @@ static inline void cpu_feature_keys_init(void) { }
>             CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
>             CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_ARCH_207S | \
>             CPU_FTR_TM_COMP | CPU_FTR_ARCH_300 | CPU_FTR_PKEY | \
> -           CPU_FTR_ARCH_31)
> +           CPU_FTR_ARCH_31 | CPU_FTR_DAWR)
>  #define CPU_FTRS_CELL  (CPU_FTR_LWSYNC | \
>             CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
>             CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \
> --
> 2.26.2
>