From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38336) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPr8J-0002Gp-Mv for qemu-devel@nongnu.org; Fri, 05 Sep 2014 06:52:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XPr8A-0001MU-LP for qemu-devel@nongnu.org; Fri, 05 Sep 2014 06:52:47 -0400 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:45210) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPr8A-0001JH-BT for qemu-devel@nongnu.org; Fri, 05 Sep 2014 06:52:38 -0400 Received: from /spool/local by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 5 Sep 2014 11:52:36 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 250E92190023 for ; Fri, 5 Sep 2014 11:52:15 +0100 (BST) Received: from d06av08.portsmouth.uk.ibm.com (d06av08.portsmouth.uk.ibm.com [9.149.37.249]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s85AqYuq22937676 for ; Fri, 5 Sep 2014 10:52:34 GMT Received: from d06av08.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av08.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s85AqXqX027598 for ; Fri, 5 Sep 2014 04:52:34 -0600 Date: Fri, 5 Sep 2014 12:52:33 +0200 From: Frank Blaschka Message-ID: <20140905105233.GA17325@tuxmaker.boeblingen.de.ibm.com> References: <20140904105223.336503578@de.ibm.com> <20140904105337.081387456@de.ibm.com> <54097466.2090502@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54097466.2090502@suse.de> Subject: Re: [Qemu-devel] [RFC][patch 3/6] KVM: s390: Add GISA support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: linux-s390@vger.kernel.org, frank.blaschka@de.ibm.com, kvm@vger.kernel.org, aik@ozlabs.ru, qemu-devel@nongnu.org, pbonzini@redhat.com On Fri, Sep 05, 2014 at 10:29:26AM +0200, Alexander Graf wrote: > > > On 04.09.14 12:52, frank.blaschka@de.ibm.com wrote: > > From: Frank Blaschka > > > > This patch adds GISA (Guest Interrupt State Area) support > > to s390 kvm. GISA can be used for exitless interrupts. The > > patch provides a set of functions for GISA related operations > > like accessing GISA fields or registering ISCs for alert. > > Exploiters of GISA will follow with additional patches. > > > > Signed-off-by: Frank Blaschka > > That's a nice feature. However, please make sure that you maintain the > abstraction levels. > > What should happen is that you request an irqfd from FLIC. Then you > associate that irqfd with the PCI device. > > Thanks to that association, both parties can now talk to each other and > negotiate their GISA number space and make sure things are connected. > > However, it should always be possible to do things without this direct > IRQ injection. > > So you should be able to receive an irqfd event when an IRQ happened, so > that VFIO user space applications can also handle interrupts for example. > > And the same applies for interrupt injection. We also need to be able to > inject an adapter interrupt from QEMU for emulated devices ;). > OK, assuming we are doing the vfio solution expoiting GISA would be a second step. Will take your feedback into account. THX! > > Alex > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >