From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 08/11] KVM: implement multiple address spaces Date: Wed, 20 May 2015 20:17:29 +0200 Message-ID: <555CCFB9.8090300@redhat.com> References: <1431956923-35602-1-git-send-email-pbonzini@redhat.com> <1431956923-35602-9-git-send-email-pbonzini@redhat.com> <20150519133240.GA32489@potion.brq.redhat.com> <555B6291.1070102@redhat.com> <20150519182810.GA29273@potion.brq.redhat.com> <555C32AD.4040704@redhat.com> <20150520154601.GA2176@potion.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Xiao Guangrong , bdas@redhat.com To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Return-path: In-Reply-To: <20150520154601.GA2176@potion.brq.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 20/05/2015 17:46, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: > I am a bit worried about the explosion that would happen if we wanted= , > for example, per-VCPU address spaces Those would be very expensive. If we were to implement relocatable API= C base, we would have to do it in a different way than with memslots. > My main issue (orthogonal to layering) is that we don't allow a way t= o > let userspace tell us that some slots in different name spaces are th= e > same slot. We're losing information that could be useful in the futu= re > (I can only think of less slot queries for dirty log now). You're right. On the other hand, I think the ship has sailed the momen= t the dirty log was GPA-indexed. > What I like about your solution is that it fits existing code really > well, is easily modified if needs change, and that it already exists. Yes, it does fit existing code really well. Thanks for the discussion! Paolo