From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1M6s0q-0008V2-OK for qemu-devel@nongnu.org; Wed, 20 May 2009 16:03:40 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1M6s0m-0008T9-SV for qemu-devel@nongnu.org; Wed, 20 May 2009 16:03:40 -0400 Received: from [199.232.76.173] (port=36533 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1M6s0m-0008Sw-MM for qemu-devel@nongnu.org; Wed, 20 May 2009 16:03:36 -0400 Received: from mx2.redhat.com ([66.187.237.31]:48370) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1M6s0m-0003SC-1s for qemu-devel@nongnu.org; Wed, 20 May 2009 16:03:36 -0400 Date: Wed, 20 May 2009 23:02:24 +0300 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] [PATCH] qemu: msi irq allocation api Message-ID: <20090520200224.GA23500@redhat.com> References: <20090520162130.GA22109@redhat.com> <20090520173536.GA22935@redhat.com> <20090520182818.GC22935@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: Carsten Otte , kvm@vger.kernel.org, Rusty Russell , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, Christian Borntraeger , avi@redhat.com On Wed, May 20, 2009 at 09:38:58PM +0300, Blue Swirl wrote: > On 5/20/09, Michael S. Tsirkin wrote: > > On Wed, May 20, 2009 at 08:44:31PM +0300, Blue Swirl wrote: > > > On 5/20/09, Michael S. Tsirkin wrote: > > > > On Wed, May 20, 2009 at 08:21:01PM +0300, Blue Swirl wrote: > > > > > On 5/20/09, Michael S. Tsirkin wrote: > > > > > > define api for allocating/setting up msi-x irqs, and for updating them > > > > > > with msi-x vector information, supply implementation in ioapic. Please > > > > > > comment on this API: I intend to port my msi-x patch to work on top of > > > > > > it. > > > > > > > > > > > > Signed-off-by: Michael S. Tsirkin > > > > > > > > > > Sparc64 also uses packets ("mondos", not implemented yet) for > > > > > interrupt vector data, there the packet size is 8 * 64 bits. > > > > > I think we should aim for a more generic API that covers this case also. > > > > > > > > > > > > Are you sure this is a good idea? MSI is tied to PCI, and PCI only has > > > > MSI, not "mondos". What code would benefit from this abstraction? > > > > > > Sparc64 emulation, of course. I think also the API would be neater. > > > > > > Since "mondos" are not interrupts, why use irqs for them? > > I just said above that they are used for interrupt vector data. What > makes you think they are not interrupts? I'm sorry, I don't really know anything about sparc. All I am saying is that in PCI, interrupts never pass data, so qemu_set_irq as it is now, is a good API to send them. For the sparc feature you describe, you probably want to add a message data parameter to qemu_set_irq, but it's not really useful for MSI. -- MST