linux-mips
[Top] [All Lists]

Re: [PATCH 00/18] KVM/MIPS32: Support for the new Virtualization ASE (VZ

To: Sanjay Lal <sanjayl@kymasys.com>
Subject: Re: [PATCH 00/18] KVM/MIPS32: Support for the new Virtualization ASE (VZ-ASE)
From: "Maciej W. Rozycki" <macro@linux-mips.org>
Date: Mon, 20 May 2013 19:36:23 +0100 (BST)
Cc: David Daney <ddaney.cavm@gmail.com>, kvm@vger.kernel.org, linux-mips@linux-mips.org, Ralf Baechle <ralf@linux-mips.org>, Gleb Natapov <gleb@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>
In-reply-to: <456B70C6-A896-4B94-B8EF-DE6ED26CE859@kymasys.com>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <n> <1368942460-15577-1-git-send-email-sanjayl@kymasys.com> <519A4640.6060202@gmail.com> <456B70C6-A896-4B94-B8EF-DE6ED26CE859@kymasys.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Alpine 2.03 (LFD 1266 2009-07-14)
On Mon, 20 May 2013, Sanjay Lal wrote:

> (1) Newer versions of the MIPS architecture define scratch registers for 
> just this purpose, but since we have to support standard MIPS32R2 
> processors, we use the DDataLo Register (CP0 Register 28, Select 3) as a 
> scratch register to save k0 and save k1 @ a known offset from EBASE.

 That's rather risky as the implementation of this register (and its 
presence in the first place) is processor-specific.  Do you maintain a 
list of PRId values the use of this register is safe with?

  Maciej

<Prev in Thread] Current Thread [Next in Thread>