From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757363Ab3CSSj3 (ORCPT ); Tue, 19 Mar 2013 14:39:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2450 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757316Ab3CSSj2 (ORCPT ); Tue, 19 Mar 2013 14:39:28 -0400 Message-ID: <5148B0DC.9000609@redhat.com> Date: Tue, 19 Mar 2013 19:39:24 +0100 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130219 Thunderbird/17.0.3 MIME-Version: 1.0 To: Gleb Natapov CC: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH] x86: let userspace inject interrupts into the local APIC References: <1363708273-19653-1-git-send-email-pbonzini@redhat.com> <20130319181323.GL19292@redhat.com> In-Reply-To: <20130319181323.GL19292@redhat.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 19/03/2013 19:13, Gleb Natapov ha scritto: >> > There is no way for userspace to inject interrupts into a VCPU's >> > local APIC, which is important in order to inject INITs coming from >> > the chipset. KVM_INTERRUPT is currently disabled when the in-kernel >> > local APIC is used, so we can repurpose it. The shorthand destination >> > field must contain APIC_DEST_SELF, which has a double effect: first, >> > the ICR2 register is not used and the 32-bit field of KVM_INTERRUPT is >> > enough; second, it ensures that the valid range of the irq field is >> > distinct in the userspace-APIC and kernel-APIC cases. >> > > Init coming from triggering INIT# line should not be modeled as INIT coming from > APIC. Then Jan's patch was wrong, and INIT should not have been an apic event (perhaps SIPI should). > In fact INIT cannot be send using SELF shorthand. Where does the SDM say that? Paolo > If APIC code will be fixed to check for that this code will break.