From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: Re: [PATCH kvm-unit-tests] arm: fix crash when caches are off Date: Tue, 16 Sep 2014 08:57:31 -0400 (EDT) Message-ID: <1230672875.5036288.1410872251140.JavaMail.zimbra@redhat.com> References: <1410833175-25547-1-git-send-email-drjones@redhat.com> <5417F159.1050501@redhat.com> <198129286.4990140.1410869523048.JavaMail.zimbra@redhat.com> <54182D09.9000700@redhat.com> <1003075385.5021814.1410871383104.JavaMail.zimbra@redhat.com> <5418315B.6020201@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, christoffer dall , marc zyngier To: Paolo Bonzini Return-path: Received: from mx4-phx2.redhat.com ([209.132.183.25]:45463 "EHLO mx4-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753206AbaIPM5g (ORCPT ); Tue, 16 Sep 2014 08:57:36 -0400 In-Reply-To: <5418315B.6020201@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: ----- Original Message ----- > Il 16/09/2014 14:43, Andrew Jones ha scritto: > > I don't think we need to worry about this case. AFAIU, enabling the > > caches for a particular cpu shouldn't require any synchronization. > > So we should be able to do > > > > enable caches > > spin_lock > > start other processors > > spin_unlock > > Ok, I'll test and apply your patch then. > > Once you change the code to enable caches, please consider hanging on > spin_lock with caches disabled. Unfortunately I can't do that without changing spin_lock into a wrapper function. Early setup code calls functions that use spin_locks, e.g. puts(), and we won't want to move the cache enablement into early setup code, as that should be left for unit tests to turn on off as they wish. Thus we either need to be able to change the spin_lock implementation dynamically, or just leave the test/return as is. drew > > Paolo > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >