From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [RFC PATCH 0/2] KVM: x86: guest exit microoptimization Date: Fri, 1 Jul 2016 18:45:14 +0200 Message-ID: <7399af63-a751-a2dd-d8a4-77aee0bf5996@redhat.com> References: <1466065297-4644-1-git-send-email-pbonzini@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: bsd@redhat.com, rkrcmar@redhat.com To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Return-path: In-Reply-To: <1466065297-4644-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.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