From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] qemu-kvm: fix no gsi routing warning Date: Mon, 21 Sep 2009 22:50:24 +0300 Message-ID: <20090921195024.GA29784@redhat.com> References: <20090921145136.GA29405@redhat.com> <4AB7940D.1030404@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, quintela@redhat.com, hch@lst.de To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:9099 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753579AbZIUTwN (ORCPT ); Mon, 21 Sep 2009 15:52:13 -0400 Content-Disposition: inline In-Reply-To: <4AB7940D.1030404@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Sep 21, 2009 at 05:56:13PM +0300, Avi Kivity wrote: > On 09/21/2009 05:51 PM, Michael S. Tsirkin wrote: >> When running on host kernel which does not let the guest manupulate the >> gsi routing, and user requested MSI-X to be enabled, we get the >> following warnings: >> kvm_msix_add: kvm_get_irq_route_gsi failed: No space left on device >> kvm_msix_update: kvm_update_routing_entry failed: Invalid argument >> >> What really happens is that we report a failure to allocate >> a vector to the guest, it will retry and finally disable MSI. >> >> Make this clearer by checking for gsi capability and warning about >> the error in a readable form. >> >> > > Can we disable msix What we do effectively disables msix. > (or, abort qemu at startup and request that the user > disable msix) if the kernel doesn't provide required features? > It's > better than a runtime error. Note it's a warning, not an error. We have a similar failure mode when we run out of gsi entries, and that can not be checked upfront. I prefer having it fail in the same way, so that this failure path in guest drivers is excercised and tested. > -- > error compiling committee.c: too many arguments to function