From nobody Sat May 18 11:26:06 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1582710335; cv=none; d=zohomail.com; s=zohoarc; b=TcNcoi/VIyIJe0KwiaY1Gx48D6L635uAO/5r6x4OtaUkQ4rNmWp5Q3+ueAviXLe6LPi8+65qwsaiLPbUjauN7oc81hwQoC754rQeC2HMCsJO9IfSTIUl7IBqF2UEpfNaTvjFaNCJRaiJGqY7z85g0MPCz/Ujaxx2bM2FV2HBf98= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1582710335; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To; bh=jTBdS1JLqqCvuybDhiFI6N2Egv85tKQ0QzmPjiOJZVU=; b=nonSisKrhHNdvpmhKufIWchdgBUiHOwDIG0W9Z0XjwGX5Fw7fBJY1U/MiWalL+9lMQPNTSTbTUWAx1k/6H+LocV6tlHraT+hmF/hTBGn0rCeDGRUKQ/HsZCopAP08ZgTfsVoveXXu6HaN84QF5yJGN2k3V4/XbC3AUBE61irC6s= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1582710335964213.267535942942; Wed, 26 Feb 2020 01:45:35 -0800 (PST) Received: from localhost ([::1]:41108 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6tG2-0005K1-Hx for importer@patchew.org; Wed, 26 Feb 2020 04:45:34 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:55911) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6tFE-0004WO-0w for qemu-devel@nongnu.org; Wed, 26 Feb 2020 04:44:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j6tFA-0004EX-Vv for qemu-devel@nongnu.org; Wed, 26 Feb 2020 04:44:41 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:46941 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j6tFA-0004DO-RN for qemu-devel@nongnu.org; Wed, 26 Feb 2020 04:44:40 -0500 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-34-FM4SGMMON1yeJr4IPdPiwg-1; Wed, 26 Feb 2020 04:44:38 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2E1B313F9; Wed, 26 Feb 2020 09:44:37 +0000 (UTC) Received: from jason-ThinkPad-X1-Carbon-6th.redhat.com (ovpn-13-217.pek2.redhat.com [10.72.13.217]) by smtp.corp.redhat.com (Postfix) with ESMTP id 611A25C545; Wed, 26 Feb 2020 09:44:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582710280; 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; bh=jTBdS1JLqqCvuybDhiFI6N2Egv85tKQ0QzmPjiOJZVU=; b=DwDbckHZYJ5U+blu2SrMaw4PwlVQky31icgll/K27VetCeTSN46qpU/pxAYrX1Siys2hk4 PG0UhOf7/LtB89zJUWSyMixqvK3VoFoDBlNO6FYImS2vMkNBZ6u1YVbDXeJuQZgBrDn34I UDoeoPI5weS8u5YISs4dpjekL+eMSF0= X-MC-Unique: FM4SGMMON1yeJr4IPdPiwg-1 From: Jason Wang To: mst@redhat.com, qemu-devel@nongnu.org Subject: [PATCH V2] vhost: correctly turn on VIRTIO_F_IOMMU_PLATFORM Date: Wed, 26 Feb 2020 17:43:57 +0800 Message-Id: <20200226094357.25061-1-jasowang@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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: pasic@linux.ibm.com, Jason Wang , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" We turn on device IOTLB via VIRTIO_F_IOMMU_PLATFORM unconditionally on platform without IOMMU support. This can lead unnecessary IOTLB transactions which will damage the performance. Fixing this by check whether the device is backed by IOMMU and disable device IOTLB. Reported-by: Halil Pasic Fixes: c471ad0e9bd46 ("vhost_net: device IOTLB support") Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang Reviewed-by: Halil Pasic Tested-by: Halil Pasic --- Changes from V1: - do not check acked_features - reuse vhost_dev_has_iommu() --- hw/virtio/vhost.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 9edfadc81d..9182a00495 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -290,7 +290,14 @@ static int vhost_dev_has_iommu(struct vhost_dev *dev) { VirtIODevice *vdev =3D dev->vdev; =20 - return virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); + /* + * For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support + * incremental memory mapping API via IOTLB API. For platform that + * does not have IOMMU, there's no need to enable this feature + * which may cause unnecessary IOTLB miss/update trnasactions. + */ + return vdev->dma_as !=3D &address_space_memory && + virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); } =20 static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr, @@ -765,6 +772,9 @@ static int vhost_dev_set_features(struct vhost_dev *dev, if (enable_log) { features |=3D 0x1ULL << VHOST_F_LOG_ALL; } + if (!vhost_dev_has_iommu(dev)) { + features &=3D ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM); + } r =3D dev->vhost_ops->vhost_set_features(dev, features); if (r < 0) { VHOST_OPS_DEBUG("vhost_set_features failed"); --=20 2.19.1