From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757791Ab3CTK5C (ORCPT ); Wed, 20 Mar 2013 06:57:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33263 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047Ab3CTK47 (ORCPT ); Wed, 20 Mar 2013 06:56:59 -0400 Date: Wed, 20 Mar 2013 12:56:58 +0200 From: Gleb Natapov To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH] x86: let userspace inject interrupts into the local APIC Message-ID: <20130320105657.GC3889@redhat.com> References: <1363708273-19653-1-git-send-email-pbonzini@redhat.com> <20130319181323.GL19292@redhat.com> <5148B0DC.9000609@redhat.com> <20130319185025.GM19292@redhat.com> <5148C909.30103@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5148C909.30103@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 19, 2013 at 09:22:33PM +0100, Paolo Bonzini wrote: > Il 19/03/2013 19:50, Gleb Natapov ha scritto: > > On Tue, Mar 19, 2013 at 07:39:24PM +0100, Paolo Bonzini wrote: > >> 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). > >> > > If it goes through APIC it is. > > Ok, I'll extract KVM_APIC_INIT handling into a separate function and > call it synchronously from KVM_INTERRUPT, with irq = -1 > (KVM_INTERRUPT_INIT, similar to PPC's values of irq). > KVM_INTERRUPT_INIT will be accessible even with in-kernel irqchip. > Why should it be accessible with in-kernel irqchip? The only valid value for mp_state is RUNNING with userspace irqchip. We even validate it in kvm_arch_vcpu_ioctl_set_mpstate() now. > >>> In fact INIT cannot be send using SELF shorthand. > >> > >> Where does the SDM say that? > >> > > Table 10-3. > > Yeah, table 10-6 and 10-7 here. > Hmm, somebody needs to update SDM. Mine is from January 2013. -- Gleb.