From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH 0/2] arm64: Add support for 48-bit Physical Addresses
Date: Wed, 27 Nov 2013 17:59:41 +0000 [thread overview]
Message-ID: <5296330D.9010801@arm.com> (raw)
In-Reply-To: <CAC8NTUXiMpjNh+GBTGcLDJ2hevskWnD6PE66ZaFxBAdUuy2nbg@mail.gmail.com>
On 27/11/13 15:33, Radha Mohan wrote:
> On Wed, Nov 27, 2013 at 4:34 PM, Marc Zyngier <marc.zyngier@arm•com> wrote:
>> [CC-ing the maintainers - seems odd they were not cc-ed the first place]
>>
>> On 27/11/13 07:34, mohun106 at gmail.com wrote:
>>> From: Radha Mohan Chintakuntla <rchintakuntla@cavium•com>
>>>
>>> This patch series provides an implementation of supporting 48-bit
>>> Physical Addresses for ARMv8 platforms. It is the maximum width that
>>> any ARMv8 based processor can support.
>>>
>>> The implementation extends the existing support of 40-bit PA.The kernel
>>> and user space will now be able to access 128TB each. With 4KB page size
>>> the Linux now will be using 4 levels of page tables by making use of
>>> 'pud'. And with 64KB page size the Linux will be using 3 levels of page
>>> tables.
>>>
>>> The code has been tested with LTP.
>>
>> Aside from finding out whether or not this is a useful change, this
>> breaks KVM, more specifically the way kernel pages are mapped into HYP.
>> Also, guests will still be limited to 40-bit IPAs, and the stage-2
>> output range needs to be addressed as well.
>
> This is useful for platforms (like ours) that will use 48-bit PAs.
> Sooner or later there will
> be such processors.
So should the 4-level page table cost be unconditionally forced onto all
implementations?
> And yes, I haven't checked on KVM.
Yeah, tiny detail... ;-)
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2013-11-27 17:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-27 7:34 [RFC PATCH 0/2] arm64: Add support for 48-bit Physical Addresses mohun106 at gmail.com
2013-11-27 7:34 ` [RFC PATCH 1/2] arm64: Add 48-bit PA support for 4KB page size mohun106 at gmail.com
2013-11-27 11:14 ` Mark Rutland
2013-11-27 16:00 ` Radha Mohan
2013-11-27 7:34 ` [RFC PATCH 2/2] arm64: Add 48-bit PA support for 64KB " mohun106 at gmail.com
2013-11-27 11:30 ` Mark Rutland
2013-11-27 11:04 ` [RFC PATCH 0/2] arm64: Add support for 48-bit Physical Addresses Marc Zyngier
2013-11-27 15:33 ` Radha Mohan
2013-11-27 15:50 ` Will Deacon
2013-11-27 17:59 ` Marc Zyngier [this message]
2013-11-28 2:14 ` Radha Mohan
2013-12-05 14:35 ` Radha Mohan
2013-12-05 15:10 ` Marc Zyngier
2013-12-05 17:30 ` Catalin Marinas
2013-12-10 16:53 ` Radha Mohan
2013-12-10 17:02 ` Catalin Marinas
2013-12-11 9:18 ` Radha Mohan
2013-12-05 16:53 ` Catalin Marinas
2013-11-28 9:29 ` Steve Capper
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