From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758644Ab2FCH26 (ORCPT ); Sun, 3 Jun 2012 03:28:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:31419 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752723Ab2FCH15 (ORCPT ); Sun, 3 Jun 2012 03:27:57 -0400 Date: Sun, 3 Jun 2012 10:27:53 +0300 From: "Michael S. Tsirkin" To: x86@kernel.org, kvm@vger.kernel.org Cc: Ingo Molnar , "H. Peter Anvin" , Avi Kivity , Marcelo Tosatti , gleb@redhat.com, Linus Torvalds , linux-kernel@vger.kernel.org, Thomas Gleixner Subject: [PATCHv6 1/8] kvm: document lapic regs field Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The logic in find_highest_vector looks strange until you realize the reason for the weird memory layout, which is because this is what the CPU microcode expects. Add a comment so this stops tripping people up. Signed-off-by: Michael S. Tsirkin --- arch/x86/kvm/lapic.h | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 6f4ce25..d29da25 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -13,6 +13,11 @@ struct kvm_lapic { u32 divide_count; struct kvm_vcpu *vcpu; bool irr_pending; + /** + * APIC register page. The layout matches the register layout seen by + * the guest 1:1, because it is accessed by the vmx microcode. + * Note: Only one register, the TPR, is used by the microcode. + */ void *regs; gpa_t vapic_addr; struct page *vapic_page; -- MST