From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1M79b7-0006rS-Cy for qemu-devel@nongnu.org; Thu, 21 May 2009 10:50:17 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1M79b3-0006po-Sa for qemu-devel@nongnu.org; Thu, 21 May 2009 10:50:17 -0400 Received: from [199.232.76.173] (port=44668 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1M79b3-0006pk-Ob for qemu-devel@nongnu.org; Thu, 21 May 2009 10:50:13 -0400 Received: from mx2.redhat.com ([66.187.237.31]:34167) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1M79b3-0006mQ-Ai for qemu-devel@nongnu.org; Thu, 21 May 2009 10:50:13 -0400 Date: Thu, 21 May 2009 17:46:34 +0300 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] [PATCH] qemu: msi irq allocation api Message-ID: <20090521144634.GK25309@redhat.com> References: <20090520162130.GA22109@redhat.com> <200905211409.33325.paul@codesourcery.com> <20090521131231.GH25309@redhat.com> <200905211423.20843.paul@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200905211423.20843.paul@codesourcery.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: Carsten Otte , kvm@vger.kernel.org, Rusty Russell , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, Christian Borntraeger , Avi Kivity On Thu, May 21, 2009 at 02:23:20PM +0100, Paul Brook wrote: > > > MSI provides multiple edge triggered interrupts, whereas traditional mode > > > provides a single level triggered interrupt. My guess is most devices > > > will want to treat these differently anyway. > > > > So, is qemu_send_msi better than qemu_set_irq. > > Neither. pci_send_msi, which is a trivial wrapper around stl_phys. I guess I'll start with that. This only works if target_phys_addr_t is a 64 bit field (because MSI addresses are typically outside the 32 bit memory space), I guess the simplest solution is to disable MSI if it's not so. -- MST