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From: Borislav Petkov <bp@alien8.de>
To: Joerg Roedel <joro@8bytes.org>
Cc: x86@kernel.org, Joerg Roedel <jroedel@suse.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Kees Cook <keescook@chromium.org>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	Martin Radev <martin.b.radev@gmail.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 5/5] x86/sev-es: Do not support MMIO to/from encrypted memory
Date: Tue, 27 Oct 2020 12:26:35 +0100	[thread overview]
Message-ID: <20201027112635.GF15580@zn.tnic> (raw)
In-Reply-To: <20201021123938.3696-6-joro@8bytes.org>

On Wed, Oct 21, 2020 at 02:39:38PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
> 
> MMIO memory is usually not mapped encrypted, so there is no reason to
> support emulated MMIO when it is mapped encrypted.
> 
> This prevents a possible hypervisor attack where it maps a RAM page as

"Prevent... "

> an MMIO page in the nested page-table, so that any guest access to it
> will trigger a #VC exception and leak the data on that page to the
						^

"... via the GHCB (like with normal MMIO)... "

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

      reply	other threads:[~2020-10-27 11:26 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-21 12:39 [PATCH v3 0/5] x86/sev-es: Mitigate some HV attack vectors Joerg Roedel
2020-10-21 12:39 ` [PATCH v3 1/5] x86/boot/compressed/64: Introduce sev_status Joerg Roedel
2020-10-26 18:27   ` Borislav Petkov
2020-10-28  8:23     ` Joerg Roedel
2020-10-28 16:50       ` Arvind Sankar
2020-10-28 16:55         ` Joerg Roedel
2020-10-21 12:39 ` [PATCH v3 2/5] x86/boot/compressed/64: Add CPUID sanity check to early #VC handler Joerg Roedel
2020-10-27 10:38   ` Borislav Petkov
2020-10-28  8:31     ` Joerg Roedel
2020-10-21 12:39 ` [PATCH v3 3/5] x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path Joerg Roedel
2020-10-27 11:08   ` Borislav Petkov
2020-10-28  8:38     ` Joerg Roedel
2020-10-27 11:09   ` Borislav Petkov
2020-10-21 12:39 ` [PATCH v3 4/5] x86/head/64: Check SEV encryption before switching to kernel page-table Joerg Roedel
2020-10-27 11:20   ` Borislav Petkov
2020-10-21 12:39 ` [PATCH v3 5/5] x86/sev-es: Do not support MMIO to/from encrypted memory Joerg Roedel
2020-10-27 11:26   ` Borislav Petkov [this message]

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