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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Laurent Dufour <ldufour@linux.ibm.com>, kvm-ppc@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org
Cc:     paulus@samba.org, linux-kernel@vger.kernel.org,
        Alexey Kardashevskiy <aik@ozlabs.ru>, benh@kernel.crashing.org
Subject: Re: [PATCH] KVM: PPC: Book3S HV: read ibm,secure-memory nodes
In-Reply-To: <20200416162715.45846-1-ldufour@linux.ibm.com>
References: <20200416162715.45846-1-ldufour@linux.ibm.com>
Date:   Tue, 21 Apr 2020 23:34:59 +1000
Message-ID: <87k129gdx8.fsf@mpe.ellerman.id.au>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
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Hi Laurent,

Laurent Dufour <ldufour@linux.ibm.com> writes:
> The newly introduced ibm,secure-memory nodes supersede the
> ibm,uv-firmware's property secure-memory-ranges.

Is either documented in a device tree binding document anywhere?

cheers

> Firmware will no more expose the secure-memory-ranges property so first
> read the new one and if not found rollback to the older one.
>
> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
> ---
>  arch/powerpc/kvm/book3s_hv_uvmem.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
> index 53b88cae3e73..ad950f8996e0 100644
> --- a/arch/powerpc/kvm/book3s_hv_uvmem.c
> +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
> @@ -735,6 +735,20 @@ static u64 kvmppc_get_secmem_size(void)
>  	const __be32 *prop;
>  	u64 size = 0;
>  
> +	/*
> +	 * First try the new ibm,secure-memory nodes which supersede the
> +	 * secure-memory-ranges property.
> +	 * If we found somes, no need to read the deprecated one.
> +	 */
> +	for_each_compatible_node(np, NULL, "ibm,secure-memory") {
> +		prop = of_get_property(np, "reg", &len);
> +		if (!prop)
> +			continue;
> +		size += of_read_number(prop + 2, 2);
> +	}
> +	if (size)
> +		return size;
> +
>  	np = of_find_compatible_node(NULL, NULL, "ibm,uv-firmware");
>  	if (!np)
>  		goto out;
> -- 
> 2.26.1