From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932193AbcBIPGW (ORCPT ); Tue, 9 Feb 2016 10:06:22 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:32924 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752448AbcBIPGU (ORCPT ); Tue, 9 Feb 2016 10:06:20 -0500 Subject: Re: [PATCH 1/3] KVM: APIC: remove unnecessary double checks on APIC existence To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= References: <1454948146-35353-1-git-send-email-pbonzini@redhat.com> <1454948146-35353-2-git-send-email-pbonzini@redhat.com> <20160209135502.GA30378@potion.brq.redhat.com> Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org From: Paolo Bonzini Message-ID: <56BA0069.30606@redhat.com> Date: Tue, 9 Feb 2016 16:06:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <20160209135502.GA30378@potion.brq.redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/02/2016 14:55, Radim Krčmář wrote: > This is most likely going to bug on the following path: > handle_apic_access -> kvm_lapic_set_eoi > > Before the change, handle_apic_access would just drop EOIs that should > have gone to user space ... I'm not sure if we tested it, or the path is > really never taken. cpu_need_virtualize_apic_accesses is needed to set SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES (vmx_secondary_exec_control) and SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES is required to get to handle_apic_access. Paolo