From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbbEFQtu (ORCPT ); Wed, 6 May 2015 12:49:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37339 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750965AbbEFQtq (ORCPT ); Wed, 6 May 2015 12:49:46 -0400 From: Bandan Das To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, rkrcmar@redhat.com, guangrong.xiao@linux.intel.com, Yang Zhang , wanpeng.li@linux.intel.com Subject: Re: [PATCH 06/13] KVM: x86: pass the whole hflags field to emulator and back References: <1430393772-27208-1-git-send-email-pbonzini@redhat.com> <1430393772-27208-7-git-send-email-pbonzini@redhat.com> <5548ECEB.3090900@redhat.com> Date: Wed, 06 May 2015 12:49:39 -0400 In-Reply-To: <5548ECEB.3090900@redhat.com> (Paolo Bonzini's message of "Tue, 05 May 2015 18:16:43 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paolo Bonzini writes: > On 05/05/2015 17:47, Bandan Das wrote: >> > The hflags field will contain information about system management mode >> > and will be useful for the emulator. Pass the entire field rather than >> > just the guest-mode information. >> >> With respect to maintaining maximum isolation between vcpu internals and >> the emulator, > > Isolation is maintained. hflags are simply parts of the processor state > that are not visible to the guest, you can choose to include them as > separate flags or in a single one. Bundling them in a single flag makes > it a bit faster to pass around many of them. > > While we do not need all of them in the emulator, that's in some cases a > limitation of the emulator. For example, if we wanted to emulate > CLGI/STGI we would need either HF_GIF_MASK or another . Likewise, > HF_NMI_MASK could replace emulator_set_nmi_mask (especially in v2 of the > series, which will add kvm_set_hflags). > > However, if you prefer, I can change it to "bool smm_mode" + a new > smm_exit emulator callback. No, this makes sense. It's better to just pass hflags then to pass bits individually. > Paolo > >> why not just "bool smm_mode" ? >>