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Date: Mon, 10 Jan 2022 15:22:19 +1000
From: Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH v3 3/6] KVM: PPC: Don't use pr_emerg when mmio emulation
 fails
To: Fabiano Rosas <farosas@linux.ibm.com>, kvm-ppc@vger.kernel.org
References: <20220107210012.4091153-1-farosas@linux.ibm.com>
 <20220107210012.4091153-4-farosas@linux.ibm.com>
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Excerpts from Fabiano Rosas's message of January 8, 2022 7:00 am:
> If MMIO emulation fails we deliver a Program interrupt to the
> guest. This is a normal event for the host, so use pr_info.
>=20
> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
> ---

Should it be rate limited to prevent guest spamming host log? In the=20
case of informational messages it's always good if it gives the=20
administrator some idea of what to do with it. If it's normal
for the host does it even need a message? If yes, then identifying which
guest and adding something like "(this might becaused by a bug in guest=20
driver)" would set the poor admin's mind at rest.

Thanks,
Nick

>  arch/powerpc/kvm/powerpc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 92e552ab5a77..4d7d0d080232 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -308,7 +308,7 @@ int kvmppc_emulate_mmio(struct kvm_vcpu *vcpu)
> =20
>  		kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
>  		/* XXX Deliver Program interrupt to guest. */
> -		pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst);
> +		pr_info("%s: emulation failed (%08x)\n", __func__, last_inst);
>  		r =3D RESUME_HOST;
>  		break;
>  	}
> --=20
> 2.33.1
>=20
>=20

From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicholas Piggin <npiggin@gmail.com>
Date: Mon, 10 Jan 2022 05:22:19 +0000
Subject: Re: [PATCH v3 3/6] KVM: PPC: Don't use pr_emerg when mmio emulation fails
Message-Id: <1641791924.shozt0u4v5.astroid@bobo.none>
List-Id: <kvm-ppc.vger.kernel.org>
References: <20220107210012.4091153-1-farosas@linux.ibm.com>
 <20220107210012.4091153-4-farosas@linux.ibm.com>
In-Reply-To: <20220107210012.4091153-4-farosas@linux.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: Fabiano Rosas <farosas@linux.ibm.com>, kvm-ppc@vger.kernel.org
Cc: aik@ozlabs.ru, linuxppc-dev@lists.ozlabs.org

Excerpts from Fabiano Rosas's message of January 8, 2022 7:00 am:
> If MMIO emulation fails we deliver a Program interrupt to the
> guest. This is a normal event for the host, so use pr_info.
> 
> Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
> ---

Should it be rate limited to prevent guest spamming host log? In the 
case of informational messages it's always good if it gives the 
administrator some idea of what to do with it. If it's normal
for the host does it even need a message? If yes, then identifying which
guest and adding something like "(this might becaused by a bug in guest 
driver)" would set the poor admin's mind at rest.

Thanks,
Nick

>  arch/powerpc/kvm/powerpc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 92e552ab5a77..4d7d0d080232 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -308,7 +308,7 @@ int kvmppc_emulate_mmio(struct kvm_vcpu *vcpu)
>  
>  		kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
>  		/* XXX Deliver Program interrupt to guest. */
> -		pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst);
> +		pr_info("%s: emulation failed (%08x)\n", __func__, last_inst);
>  		r = RESUME_HOST;
>  		break;
>  	}
> -- 
> 2.33.1
> 
>