From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1Uqrxt-0007jn-0y for mharc-qemu-trivial@gnu.org; Sun, 23 Jun 2013 17:36:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37027) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uqrxp-0007j8-39 for qemu-trivial@nongnu.org; Sun, 23 Jun 2013 17:36:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uqrxn-0004Zo-AJ for qemu-trivial@nongnu.org; Sun, 23 Jun 2013 17:36:49 -0400 Received: from gate.crashing.org ([63.228.1.57]:58756) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uqrxn-0004Za-1H; Sun, 23 Jun 2013 17:36:47 -0400 Received: from [127.0.0.1] (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.13.8) with ESMTP id r5NLaT8e014256; Sun, 23 Jun 2013 16:36:30 -0500 Message-ID: <1372023385.3944.108.camel@pasglop> From: Benjamin Herrenschmidt To: "Michael S. Tsirkin" Date: Mon, 24 Jun 2013 07:36:25 +1000 In-Reply-To: <20130623140736.GB20842@redhat.com> References: <1371737338-25148-1-git-send-email-aik@ozlabs.ru> <874ncshh67.fsf@codemonkey.ws> <51C39578.6020204@ozlabs.ru> <20130623140736.GB20842@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 63.228.1.57 Cc: Anthony Liguori , Alexey Kardashevskiy , qemu-devel@nongnu.org, Alexander Graf , qemu-trivial@nongnu.org, Alex Williamson , qemu-ppc@nongnu.org, Paolo Bonzini , Paul Mackerras , David Gibson Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH] RFC kvm irqfd: add directly mapped MSI IRQ support X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Jun 2013 21:36:51 -0000 On Sun, 2013-06-23 at 17:07 +0300, Michael S. Tsirkin wrote: > Yes I think that's fine really. > > Basically devices all speak MSIMessage as they should - > this is what the PCI spec says. > On all normal systems guests also speak MSIMessage so > the API which uses these makes sense for kvm. > Except, ppc architecture in its wisdom decided to hide this > in firmware. QEMU does not have firmware so the translation > has to be maintained in QEMU powerpc code. It is still not enough. There is nothing that says that an MSI address/message is unique. On pseries (among others I'm sure), this is a per-host-bridge concept since the MSIs are decoded by the PHB and turned into standard fabric interrupts there. So at least the bus needs to be passed as well. Cheers, Ben. From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37069) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uqrxu-0007ll-B7 for qemu-devel@nongnu.org; Sun, 23 Jun 2013 17:36:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uqrxt-0004b3-CU for qemu-devel@nongnu.org; Sun, 23 Jun 2013 17:36:54 -0400 Message-ID: <1372023385.3944.108.camel@pasglop> From: Benjamin Herrenschmidt Date: Mon, 24 Jun 2013 07:36:25 +1000 In-Reply-To: <20130623140736.GB20842@redhat.com> References: <1371737338-25148-1-git-send-email-aik@ozlabs.ru> <874ncshh67.fsf@codemonkey.ws> <51C39578.6020204@ozlabs.ru> <20130623140736.GB20842@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] RFC kvm irqfd: add directly mapped MSI IRQ support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Anthony Liguori , Alexey Kardashevskiy , qemu-devel@nongnu.org, Alexander Graf , qemu-trivial@nongnu.org, Alex Williamson , qemu-ppc@nongnu.org, Paolo Bonzini , Paul Mackerras , David Gibson On Sun, 2013-06-23 at 17:07 +0300, Michael S. Tsirkin wrote: > Yes I think that's fine really. > > Basically devices all speak MSIMessage as they should - > this is what the PCI spec says. > On all normal systems guests also speak MSIMessage so > the API which uses these makes sense for kvm. > Except, ppc architecture in its wisdom decided to hide this > in firmware. QEMU does not have firmware so the translation > has to be maintained in QEMU powerpc code. It is still not enough. There is nothing that says that an MSI address/message is unique. On pseries (among others I'm sure), this is a per-host-bridge concept since the MSIs are decoded by the PHB and turned into standard fabric interrupts there. So at least the bus needs to be passed as well. Cheers, Ben.