From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35378) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d7wlT-000399-As for qemu-devel@nongnu.org; Tue, 09 May 2017 00:28:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d7wlS-00024V-Eq for qemu-devel@nongnu.org; Tue, 09 May 2017 00:28:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54170) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d7wlS-00023z-92 for qemu-devel@nongnu.org; Tue, 09 May 2017 00:28:46 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4157088E60 for ; Tue, 9 May 2017 04:28:45 +0000 (UTC) From: Peter Xu Date: Tue, 9 May 2017 12:28:28 +0800 Message-Id: <1494304108-9805-4-git-send-email-peterx@redhat.com> In-Reply-To: <1494304108-9805-1-git-send-email-peterx@redhat.com> References: <1494304108-9805-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [PATCH 3/3] kvm: irqchip: skip update msi when disabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Michael S . Tsirkin" , Paolo Bonzini , peterx@redhat.com It's possible that one device kept its irqfd/virq there even when MSI/MSIX was disabled globally for that device. One example is virtio-net-pci (see commit f1d0f15a6 and virtio_pci_vq_vector_mask()). It is used as a fast path to avoid allocate/release irqfd/virq frequently when guest enables/disables MSIX. However, this fast path brought a problem to msi_route_list, that the device MSIRouteEntry is still dangling there even if MSIX disabled - then we cannot know which message to fetch, even if we can, the messages are meaningless. In this case, we can just simply ignore this entry. It's safe, since when MSIX is enabled again, we'll rebuild them no matter what. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1448813 Signed-off-by: Peter Xu --- target/i386/kvm.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 55865db..3a85b54 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -3510,12 +3510,16 @@ static void kvm_update_msi_routes_all(void *private, bool global, int cnt = 0; MSIRouteEntry *entry; MSIMessage msg; + PCIDevice *dev; + /* TODO: explicit route update */ QLIST_FOREACH(entry, &msi_route_list, list) { - cnt++; - msg = pci_get_msi_message(entry->dev, entry->vector); - kvm_irqchip_update_msi_route(kvm_state, entry->virq, - msg, entry->dev); + dev = entry->dev; + if (!msix_enabled(dev) && !msi_enabled(dev)) { + continue; + } + msg = pci_get_msi_message(dev, entry->vector); + kvm_irqchip_update_msi_route(kvm_state, entry->virq, msg, dev); } kvm_irqchip_commit_routes(kvm_state); trace_kvm_x86_update_msi_routes(cnt); -- 2.7.4