From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4F2191A05C5 for ; Tue, 23 Feb 2016 06:02:28 +1100 (AEDT) Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 22 Feb 2016 12:02:26 -0700 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 8D2151FF0023 for ; Mon, 22 Feb 2016 11:50:32 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u1MJ2MVd29884464 for ; Mon, 22 Feb 2016 12:02:22 -0700 Received: from d03av02.boulder.ibm.com (localhost [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u1MJ2M9R030650 for ; Mon, 22 Feb 2016 12:02:22 -0700 Reply-To: manoj@linux.vnet.ibm.com Subject: Re: Fwd: [PATCH v4 08/18] cxl: IRQ allocation for guests References: <1455658751-16970-9-git-send-email-fbarrat@linux.vnet.ibm.com> <56CA2CB1.5030105@linux.vnet.ibm.com> <56CA3A6F.9060402@linux.vnet.ibm.com> <56CB1F5C.9000608@linux.vnet.ibm.com> To: Frederic Barrat Cc: Ian Munsie , michael.neuling@au1.ibm.com, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org From: Manoj Kumar Message-ID: <56CB5B50.8010106@linux.vnet.ibm.com> Date: Mon, 22 Feb 2016 13:02:40 -0600 MIME-Version: 1.0 In-Reply-To: <56CB1F5C.9000608@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 2/22/2016 8:46 AM, Frederic Barrat wrote: > Le 21/02/2016 23:30, Manoj Kumar a écrit : >>> Subject: [PATCH v4 08/18] cxl: IRQ allocation for guests >>> Date: Tue, 16 Feb 2016 22:39:01 +0100 >>> From: Frederic Barrat >>> To: imunsie@au1.ibm.com, michael.neuling@au1.ibm.com, >>> mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org >>> >>> The PSL interrupt is not going to be multiplexed in a guest, so an >>> interrupt will be allocated for it for each context. >> >> Not clear why this is the case. Why cannot the CXL later still >> multiplex this in a guest? Is this a design choice, an >> architectural issue, or the complexity of implementation did >> not warrant this? From an API perspective it would have been >> preferable to not cascade this change down to all consumers, >> and have consumers aware whether they are working in a >> bare-metal or a guest environment. > > > It was a design choice made by pHyp. We cannot multiplex the PSL > interrupt with the current pHyp implementation. If that is the case, perhaps the commit message should be re-worded. As currently written, it seems like it was a choice made by this patch. The PSL interrupt cannot be multiplexed in a guest, because blah... -- Manoj Kumar