From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v8 06/15] ARM: KVM: Hypervisor identity mapping Date: Mon, 18 Jun 2012 16:12:40 +0300 Message-ID: <4FDF2948.20007@redhat.com> References: <20120615190553.24590.18391.stgit@ubuntu> <20120615190747.24590.35933.stgit@ubuntu> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: android-virt@lists.cs.columbia.edu, kvm@vger.kernel.org To: Christoffer Dall Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36471 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915Ab2FRNMs (ORCPT ); Mon, 18 Jun 2012 09:12:48 -0400 In-Reply-To: <20120615190747.24590.35933.stgit@ubuntu> Sender: kvm-owner@vger.kernel.org List-ID: On 06/15/2012 10:07 PM, Christoffer Dall wrote: > Adds support in the identity mapping feature that allows KVM to setup > identity mapping for the Hyp mode with the AP[1] bit set as required by > the specification and also supports freeing created sub pmd's after > finished use. > > These two functions: > - hyp_idmap_add(pgd, addr, end); > - hyp_idmap_del(pgd, addr, end); > are essentially calls to the same function as the non-hyp versions but > with a different argument value. KVM calls these functions to setup > and teardown the identity mapping used to initialize the hypervisor. > > Note, the hyp-version of the _del function actually frees the pmd's > pointed to by the pgd as opposed to the non-hyp version which just > clears them. I asked previously what happens if two data structures share a page, and one of them is removed. Is that handled now? How? Why not just identity map all memory? You can use large pages so it's fast and doesn't consume a lot of page table memory.-- error compiling committee.c: too many arguments to function