From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 10/18] KVM/MIPS32-VZ: Add API for VZ-ASE Capability Date: Thu, 30 May 2013 19:51:15 +0200 Message-ID: <51A79193.6080908@redhat.com> References: <1368942460-15577-1-git-send-email-sanjayl@kymasys.com> <1368942460-15577-11-git-send-email-sanjayl@kymasys.com> <51A4DC99.7040706@redhat.com> <51A7875F.4080606@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Sanjay Lal , kvm@vger.kernel.org, linux-mips@linux-mips.org, Ralf Baechle , Gleb Natapov , Marcelo Tosatti To: David Daney Return-path: Received: from mx1.redhat.com ([209.132.183.28]:41092 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965904Ab3E3Rvi (ORCPT ); Thu, 30 May 2013 13:51:38 -0400 In-Reply-To: <51A7875F.4080606@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 30/05/2013 19:07, David Daney ha scritto: > On 05/28/2013 09:34 AM, Paolo Bonzini wrote: >> Il 19/05/2013 07:47, Sanjay Lal ha scritto: >>> - Add API to allow clients (QEMU etc.) to check whether the H/W >>> supports the MIPS VZ-ASE. >> >> Why does this matter to userspace? Do the userspace have some way to >> detect if the kernel is unmodified or minimally-modified? >> > > There are (will be) two types of VM presented by MIPS KVM: > > 1) That provided by the initial patch where a faux-MIPS is emulated and > all kernel code must be in the USEG address space. > > 2) Real MIPS, addressing works as per the architecture specification. > > Presumably the user-space client would like to know which of these are > supported, as well as be able to select the desired model. Understood. It's really two different machine types. > I don't know the best way to do this, but I agree that > KVM_CAP_MIPS_VZ_ASE is probably not the best name for it. > > My idea was to have the arg of the KVM_CREATE_VM ioctl specify the > desired style Ok. How complex is it? Do you plan to do this when the patches are "really ready" for Linus' tree? Paolo