From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D736CC11D3D for ; Thu, 27 Feb 2020 16:54:33 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A1E992469F for ; Thu, 27 Feb 2020 16:54:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BAmTGNqQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A1E992469F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34626 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7MQi-0003S1-TJ for qemu-devel@archiver.kernel.org; Thu, 27 Feb 2020 11:54:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:44644) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7MPy-0002rD-SJ for qemu-devel@nongnu.org; Thu, 27 Feb 2020 11:53:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j7MPx-0002fA-QP for qemu-devel@nongnu.org; Thu, 27 Feb 2020 11:53:46 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:60825 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j7MPx-0002et-Li for qemu-devel@nongnu.org; Thu, 27 Feb 2020 11:53:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582822425; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=klQasuvkB9n35CdkmEbqUV8ZPKnOsqAm2v2UJ8nXL5c=; b=BAmTGNqQ7Xfa3hTiZkK31ILHZjnNclojJ1ZUGlzExAZ2y4uTFY4NyuzroV2OsmX4ZnjTPQ B4akvRt+ZK0X7IYDyASj32FF8WJLnY9hFpeozyUt7JQxKR5UlQNiE2XwoSKe8IelPav8AZ HEtfDmG9k9fR9Dzydd4q8HDOcb6IPbU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-325-YdK3MrCCMSix39ueJVs9Ag-1; Thu, 27 Feb 2020 11:53:41 -0500 X-MC-Unique: YdK3MrCCMSix39ueJVs9Ag-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 29002801E53 for ; Thu, 27 Feb 2020 16:53:40 +0000 (UTC) Received: from [10.36.116.59] (ovpn-116-59.ams2.redhat.com [10.36.116.59]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C87CD5DDA5; Thu, 27 Feb 2020 16:53:33 +0000 (UTC) Subject: Re: [PATCH 1/5] vfio/pci: Disable INTx fast path if using split irqchip To: Peter Xu , qemu-devel@nongnu.org References: <20200226225048.216508-1-peterx@redhat.com> <20200226225048.216508-2-peterx@redhat.com> From: Auger Eric Message-ID: <59815cf7-7fb8-faf6-4bb8-5376c87aa684@redhat.com> Date: Thu, 27 Feb 2020 17:53:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20200226225048.216508-2-peterx@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Alex Williamson , Cornelia Huck Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Peter, On 2/26/20 11:50 PM, Peter Xu wrote: > It's currently broken. Let's use the slow path to at least make it > functional. > > Signed-off-by: Peter Xu > --- > hw/vfio/pci.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > index 5e75a95129..98e0e0c994 100644 > --- a/hw/vfio/pci.c > +++ b/hw/vfio/pci.c > @@ -128,6 +128,18 @@ static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp) > return; > } > > + if (kvm_irqchip_is_split()) { > + /* > + * VFIO INTx is currently not working with split kernel > + * irqchip for level triggered interrupts. Go the slow path > + * as long as split is enabled so we can be at least > + * functional (even with poor performance). > + * > + * TODO: Remove this after all things fixed up. If this patch were to be applied sooner than the other patches as suggested in the cover letter, We may emit a warning message saying that slow path is selected due to split irqchip and this will induce perf downgrade > + */ > + return; > + } > + > /* Get to a known interrupt state */ > qemu_set_fd_handler(irqfd.fd, NULL, NULL, vdev); > vfio_mask_single_irqindex(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX); > Tested with a 5.2-rc1 kernel with reverted "654f1f13ea56 kvm: Check irqchip mode before assign irqfd" and guest booting with nomsi. Without this patch the assigned NIC does not work. This patch fixes the issue. Reviewed-by: Eric Auger Tested-by: Eric Auger Thanks Eric