From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [GIT PULL 00/15] KVM: s390: Features and fixes for next (3.18) Date: Tue, 26 Aug 2014 14:26:59 +0200 Message-ID: <53FC7D13.3050806@redhat.com> References: <1409041707-39938-1-git-send-email-borntraeger@de.ibm.com> <53FC721A.4050202@redhat.com> <53FC76A0.8060007@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Cc: KVM , Gleb Natapov , Alexander Graf , Cornelia Huck , Jens Freimann , linux-s390 , David Hildenbrand To: Christian Borntraeger Return-path: Received: from mx1.redhat.com ([209.132.183.28]:12029 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754650AbaHZM1a (ORCPT ); Tue, 26 Aug 2014 08:27:30 -0400 In-Reply-To: <53FC76A0.8060007@de.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 26/08/2014 13:59, Christian Borntraeger ha scritto: > This patch is more of a cleanup - making clear whats going on. Its not needed for something special. > > It does two things: > - encapsulate the TLB flushing - Yes, a function hiding that would also work. We decided to reuse an existing interface > - serialize the TLB flushing against other control block updates. This is not necessary, it just happens as a consequence of being a request > > Agreed, it will be a bit slower (instead of setting a field we now also set and test a request bit). > Since we only need to do that in rare cases (specific control register updates via userspace and prefix setting) The performance does not matter at all. > > I can take out that patch and redo the tag, or leave it in. Let me know. You can leave it in, I just wanted to understand better. In fact, supporting KVM_REQ_FLUSH_TLB is in general a good thing since generic MMU notifier code refers to it. Paolo