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From: "Marc-André Lureau" <marcandre.lureau@gmail.com>
To: edk2-devel@lists.01.org
Cc: Chao Zhang <chao.b.zhang@intel.com>,
	Laszlo Ersek <lersek@redhat.com>,
	 michael.d.kinney@intel.com, Paolo Bonzini <pbonzini@redhat.com>
Subject: TCG MOR and processor caches
Date: Thu, 27 Sep 2018 14:59:17 +0400	[thread overview]
Message-ID: <CAJ+F1C+83xPvG=uOq07JyiRz5+u_i-Ar0CTLxf2mJxo9yRYfrQ@mail.gmail.com> (raw)

Hi,

According to "TCG Platform Reset Attack Mitigation Specification", if
MOR bit is set, "it must initiate a vendor-specific method that
overwrites all of system memory and the processor caches"

In QuarkPlatformPkg/Platform/Pei/PlatformInit/MemoryCallback.c and
QuarkPlatformPkg/Platform/Pei/PlatformInit/MrcWrapper.c, there is some
code to clear RAM, however I don't see code that would clear the
processor caches.

For edk2/qemu, Paolo suggested it may be simpler to clear the cache
unconditionally. How would you implement that? Using
EFI_CPU_ARCH_PROTOCOL.FlushDataCache? (or direct AsmWbinvd call)

thanks

-- 
Marc-André Lureau


             reply	other threads:[~2018-09-27 10:59 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-27 10:59 Marc-André Lureau [this message]
2018-09-27 11:45 ` TCG MOR and processor caches Laszlo Ersek
2018-09-27 15:21   ` Laszlo Ersek

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