From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752233AbcGAQpY (ORCPT ); Fri, 1 Jul 2016 12:45:24 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35986 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752134AbcGAQpV (ORCPT ); Fri, 1 Jul 2016 12:45:21 -0400 Subject: Re: [RFC PATCH 0/2] KVM: x86: guest exit microoptimization To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <1466065297-4644-1-git-send-email-pbonzini@redhat.com> Cc: bsd@redhat.com, rkrcmar@redhat.com From: Paolo Bonzini Message-ID: <7399af63-a751-a2dd-d8a4-77aee0bf5996@redhat.com> Date: Fri, 1 Jul 2016 18:45:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <1466065297-4644-1-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/06/2016 10:21, Paolo Bonzini wrote: > This saves about 20 clock cycles per vmexit by avoiding a > local_irq_save/restore pair. The price is that nested VMX will break > with KVM hosts < 3.16, because the "acknowledge interrupt on exit" > feature becomes mandatory. What do you think? I'm pushing these patches. Paolo