From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [Patch v5] x86: irq_comm: Add check for RH bit in kvm_set_msi_irq Date: Tue, 21 Apr 2015 14:18:26 +0200 Message-ID: <55364012.2040004@redhat.com> References: <5502FEDB.3030606@gmail.com> <20150318225225.GA8702@amt.cnet> <550A1F6A.6030602@gmail.com> <20150319010932.GA18338@amt.cnet> <20150319130015.GA16070@potion.brq.redhat.com> <550B5309.1090805@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, gleb@kernel.org To: James Sullivan , =?UTF-8?B?UmFkaW0gS3LEjW0=?= =?UTF-8?B?w6HFmQ==?= , Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47797 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752992AbbDUMSb (ORCPT ); Tue, 21 Apr 2015 08:18:31 -0400 In-Reply-To: <550B5309.1090805@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On 19/03/2015 23:51, James Sullivan wrote: > I played around with native_compose_msi_msg and discovered the following: > > * dm=0, rh=0 => Physical Destination Mode > * dm=0, rh=1 => Failed delivery > * dm=1, rh=0 => Logical Destination Mode, No Redirection > * dm=1, rh=1 => Logical Destination Mode, Redirection > > So it seems to be the case that logical destination mode is used whenever > DM=1, regardless of RH. Furthermore, the case where DM=0 and RH=1 is > undefined, as was indicated in the closing response to the thread in > https://software.intel.com/en-us/forums/topic/288883 : So this means this patch is not necessary, right? Paolo