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From: Andy Lutomirski <luto@amacapital.net>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Marius Hillenbrand <mhillenb@amazon.de>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com, linux-mm@kvack.org,
	Alexander Graf <graf@amazon.de>,
	David Woodhouse <dwmw@amazon.co.uk>,
	the arch/x86 maintainers <x86@kernel.org>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC 00/10] Process-local memory allocations for hiding KVM secrets
Date: Wed, 12 Jun 2019 13:27:04 -0700	[thread overview]
Message-ID: <A542C98B-486C-4849-9DAC-2355F0F89A20@amacapital.net> (raw)
In-Reply-To: <eecc856f-7f3f-ed11-3457-ea832351e963@intel.com>



> On Jun 12, 2019, at 12:55 PM, Dave Hansen <dave.hansen@intel.com> wrote:
> 
>> On 6/12/19 10:08 AM, Marius Hillenbrand wrote:
>> This patch series proposes to introduce a region for what we call
>> process-local memory into the kernel's virtual address space. 
> 
> It might be fun to cc some x86 folks on this series.  They might have
> some relevant opinions. ;)
> 
> A few high-level questions:
> 
> Why go to all this trouble to hide guest state like registers if all the
> guest data itself is still mapped?
> 
> Where's the context-switching code?  Did I just miss it?
> 
> We've discussed having per-cpu page tables where a given PGD is only in
> use from one CPU at a time.  I *think* this scheme still works in such a
> case, it just adds one more PGD entry that would have to context-switched.

Fair warning: Linus is on record as absolutely hating this idea. He might change his mind, but it’s an uphill battle.

  reply	other threads:[~2019-06-12 20:27 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-12 17:08 [RFC 00/10] Process-local memory allocations for hiding KVM secrets Marius Hillenbrand
2019-06-12 17:08 ` [RFC 01/10] x86/mm/kaslr: refactor to use enum indices for regions Marius Hillenbrand
2019-06-12 17:08 ` [RFC 02/10] x86/speculation, mm: add process local virtual memory region Marius Hillenbrand
2019-06-12 17:08 ` [RFC 03/10] x86/mm, mm,kernel: add teardown for process-local memory to mm cleanup Marius Hillenbrand
2019-06-12 17:08 ` [RFC 04/10] mm: allocate virtual space for process-local memory Marius Hillenbrand
2019-06-12 17:08 ` [RFC 05/10] mm: allocate/release physical pages " Marius Hillenbrand
2019-06-12 17:08 ` [RFC 06/10] kvm/x86: add support for storing vCPU state in " Marius Hillenbrand
2019-06-12 17:08 ` [RFC 07/10] kvm, vmx: move CR2 context switch out of assembly path Marius Hillenbrand
2019-06-12 17:08 ` [RFC 08/10] kvm, vmx: move register clearing " Marius Hillenbrand
2019-06-12 17:08 ` [RFC 09/10] kvm, vmx: move gprs to process local memory Marius Hillenbrand
2019-06-12 17:08 ` [RFC 10/10] kvm, x86: move guest FPU state into " Marius Hillenbrand
2019-06-12 18:25 ` [RFC 00/10] Process-local memory allocations for hiding KVM secrets Sean Christopherson
2019-06-13  7:20   ` Alexander Graf
2019-06-13 10:54   ` Liran Alon
2019-06-12 19:55 ` Dave Hansen
2019-06-12 20:27   ` Andy Lutomirski [this message]
2019-06-12 20:41     ` Dave Hansen
2019-06-12 20:56       ` Andy Lutomirski
2019-06-13  1:30     ` Andy Lutomirski
2019-06-13  1:50       ` Nadav Amit
2019-06-13 16:16         ` Andy Lutomirski
2019-06-13  7:52       ` Alexander Graf
2019-06-13 16:13         ` Andy Lutomirski
2019-06-13 16:20           ` Dave Hansen
2019-06-13 17:29             ` Nadav Amit
2019-06-13 17:49               ` Dave Hansen
2019-06-13 20:05                 ` Sean Christopherson
2019-06-14 14:21     ` Thomas Gleixner
2019-06-16 22:18       ` Andy Lutomirski
2019-06-16 22:28         ` Thomas Gleixner
2019-06-17  7:38       ` Alexander Graf
2019-06-17 15:50         ` Dave Hansen
2019-06-17 15:54           ` Andy Lutomirski
2019-06-17 16:03             ` Dave Hansen
2019-06-17 16:14               ` Andy Lutomirski
2019-06-17 16:53                 ` Nadav Amit
2019-06-17 18:07                   ` Dave Hansen
2019-06-17 18:45                     ` Konrad Rzeszutek Wilk
2019-06-17 18:49                       ` Dave Hansen
2019-06-17 18:53                       ` Andy Lutomirski
2019-06-17 18:50                     ` Nadav Amit
2019-06-17 18:55                       ` Dave Hansen
2019-06-13  7:27   ` Alexander Graf
2019-06-13 14:19     ` Dave Hansen

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