Date: Wed, 14 Jun 2017 18:07:54 +0200
From: Borislav Petkov <bp@alien8.de>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
        kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org,
        kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        iommu@lists.linux-foundation.org, Rik van Riel <riel@redhat.com>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Toshimitsu Kani <toshi.kani@hpe.com>, Arnd Bergmann <arnd@arndb.de>,
        Jonathan Corbet <corbet@lwn.net>,
        Matt Fleming <matt@codeblueprint.co.uk>,
        "Michael S. Tsirkin" <mst@redhat.com>, Joerg Roedel <joro@8bytes.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Larry Woodman <lwoodman@redhat.com>,
        Brijesh Singh <brijesh.singh@amd.com>, Ingo Molnar <mingo@redhat.com>,
        Andy Lutomirski <luto@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dave Young <dyoung@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH v6 20/34] x86, mpparse: Use memremap to map the mpf and
 mpc data
Message-ID: <20170614160754.c4ywbf5ktqwgc4ij@pd.tnic>
References: <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net>
 <20170607191643.28645.91679.stgit@tlendack-t1.amdoffice.net>
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On Wed, Jun 07, 2017 at 02:16:43PM -0500, Tom Lendacky wrote:
> The SMP MP-table is built by UEFI and placed in memory in a decrypted
> state. These tables are accessed using a mix of early_memremap(),
> early_memunmap(), phys_to_virt() and virt_to_phys(). Change all accesses
> to use early_memremap()/early_memunmap(). This allows for proper setting
> of the encryption mask so that the data can be successfully accessed when
> SME is active.
> 
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>  arch/x86/kernel/mpparse.c |   98 ++++++++++++++++++++++++++++++++-------------
>  1 file changed, 70 insertions(+), 28 deletions(-)

...

> @@ -515,6 +516,12 @@ void __init default_get_smp_config(unsigned int early)
>  	if (acpi_lapic && acpi_ioapic)
>  		return;
>  
> +	mpf = early_memremap(mpf_base, sizeof(*mpf));
> +	if (!mpf) {
> +		pr_err("MPTABLE: mpf early_memremap() failed\n");

If you're going to introduce new prefixes then add:

#undef pr_fmt
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

at the beginning of the file so that they all say "mpparse:" instead.

And pls make that message more user-friendly: "Error mapping MP table"
or so.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.