From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH 3/3] KVM: Enable MSI-X for KVM assigned device Date: Thu, 12 Feb 2009 14:03:59 +0800 Message-ID: <200902121404.00220.sheng@linux.intel.com> References: <1234339731-3195-1-git-send-email-sheng@linux.intel.com> <1234339731-3195-4-git-send-email-sheng@linux.intel.com> <4992C937.2090708@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mga05.intel.com ([192.55.52.89]:36220 "EHLO fmsmga101.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750764AbZBLGEQ (ORCPT ); Thu, 12 Feb 2009 01:04:16 -0500 In-Reply-To: <4992C937.2090708@redhat.com> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Wednesday 11 February 2009 20:48:55 Avi Kivity wrote: > Sheng Yang wrote: > > This patch finally enable MSI-X. > > > > What we need for MSI-X: > > 1. Intercept one page in MMIO region of device. So that we can get guest > > desired MSI-X table and set up the real one. Now this have been done by > > guest, and transfer to kernel using ioctl KVM_SET_MSIX_NR and > > KVM_SET_MSIX_ENTRY. > > Looking at the patch, you're doing that in userspace. Good. > > > 2. The PCI spec allowed to change MSI-X table dynamically. That means, > > the OS can enable MSI-X, then mask one MSI-X entry, modify it, and unmask > > it. The patch didn't support this, and Linux also don't work in this way. > > What about Windows? Not sure. Don't have Windows driver to test... And only Vista and later support MSI/MSI-X, not sure it would be so aggressive... We can add some debug if such condition happened. -- regards Yang, Sheng