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From:   Richard Hughes <hughsient@gmail.com>
Date:   Fri, 19 Jun 2020 17:47:42 +0100
Message-ID: <CAD2FfiHVyt2hWBqcgtxbBaLEuxuzz6yAe1+8sK5J0SYWVEr5qQ@mail.gmail.com>
Subject: Re: [PATCH] Ability to read the MKTME status from userspace
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Borislav Petkov <bp@alien8.de>,
        Daniel Gutson <daniel@eclypsium.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, Arnd Bergmann <arnd@arndb.de>,
        Peter Zijlstra <peterz@infradead.org>,
        "David S. Miller" <davem@davemloft.net>,
        Rob Herring <robh@kernel.org>, Tony Luck <tony.luck@intel.com>,
        Rahul Tanwar <rahul.tanwar@linux.intel.com>,
        Xiaoyao Li <xiaoyao.li@intel.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Fri, 19 Jun 2020 at 17:41, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> > Yes. I want to show the user *why* TME is not available.
> So even if it is "available" that's fine, even if it is not being used?

No, it's just one more thing we can check and report. For instance,
"Full memory encryption: NO [firmware-disabled, unencrypted-swap, EFI
memory map incomplete]

> And how can you ever tell if a BIOS disables a CPU feature, yet the chip
> still has it?

Isn't that what the "x86/tme: enabled by BIOS" kernel log entry is for?

Richard.