From patchwork Thu Jan 28 14:41:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 12053835 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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 B0FDEC433E0 for ; Thu, 28 Jan 2021 14:51:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DEE564DE9 for ; Thu, 28 Jan 2021 14:51:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231859AbhA1Ovj (ORCPT ); Thu, 28 Jan 2021 09:51:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33934 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231428AbhA1OnL (ORCPT ); Thu, 28 Jan 2021 09:43:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611844904; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=M3vss1A+o8qGBdSHXfpKJnMfjABPVIgXN4y+fS2IFHc=; b=TsLyNmc15S5Vhtvpk2kmrp/Q3KkQ7WMW1Zetmj3F9sZRuoM9hQahFerpXf2edQxXBlfzDh eicdd8+H+hviUAqT9HgCabZHOLK6Rq1AIQas1qBsH0ChpvIa7wWkcqsTPkwsBAY6GPwoBA m2l9OIWm7m6Uq5M7S7D/jD4pVTeLD8I= 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-327-RVybKE0iNBiFO21dpPwxnw-1; Thu, 28 Jan 2021 09:41:42 -0500 X-MC-Unique: RVybKE0iNBiFO21dpPwxnw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A1414EC1A1; Thu, 28 Jan 2021 14:41:41 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-113-219.ams2.redhat.com [10.36.113.219]) by smtp.corp.redhat.com (Postfix) with ESMTP id 720B760875; Thu, 28 Jan 2021 14:41:39 +0000 (UTC) From: Stefano Garzarella To: virtualization@lists.linux-foundation.org Cc: Xie Yongji , "Michael S. Tsirkin" , Stefano Garzarella , Laurent Vivier , Stefan Hajnoczi , linux-kernel@vger.kernel.org, Max Gurtovoy , Jason Wang , kvm@vger.kernel.org Subject: [PATCH RFC v2 02/10] vringh: add 'iotlb_lock' to synchronize iotlb accesses Date: Thu, 28 Jan 2021 15:41:19 +0100 Message-Id: <20210128144127.113245-3-sgarzare@redhat.com> In-Reply-To: <20210128144127.113245-1-sgarzare@redhat.com> References: <20210128144127.113245-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Usually iotlb accesses are synchronized with a spinlock. Let's request it as a new parameter in vringh_set_iotlb() and hold it when we navigate the iotlb in iotlb_translate() to avoid race conditions with any new additions/deletions of ranges from the ioltb. Signed-off-by: Stefano Garzarella Acked-by: Jason Wang --- include/linux/vringh.h | 6 +++++- drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 ++- drivers/vhost/vringh.c | 9 ++++++++- 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/include/linux/vringh.h b/include/linux/vringh.h index 59bd50f99291..9c077863c8f6 100644 --- a/include/linux/vringh.h +++ b/include/linux/vringh.h @@ -46,6 +46,9 @@ struct vringh { /* IOTLB for this vring */ struct vhost_iotlb *iotlb; + /* spinlock to synchronize IOTLB accesses */ + spinlock_t *iotlb_lock; + /* The function to call to notify the guest about added buffers */ void (*notify)(struct vringh *); }; @@ -258,7 +261,8 @@ static inline __virtio64 cpu_to_vringh64(const struct vringh *vrh, u64 val) #if IS_REACHABLE(CONFIG_VHOST_IOTLB) -void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb); +void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb, + spinlock_t *iotlb_lock); int vringh_init_iotlb(struct vringh *vrh, u64 features, unsigned int num, bool weak_barriers, diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c index 2183a833fcf4..53238989713d 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -284,7 +284,8 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr) goto err_iommu; for (i = 0; i < dev_attr->nvqs; i++) - vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu); + vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu, + &vdpasim->iommu_lock); ret = iova_cache_get(); if (ret) diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 85d85faba058..f68122705719 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -1074,6 +1074,8 @@ static int iotlb_translate(const struct vringh *vrh, int ret = 0; u64 s = 0; + spin_lock(vrh->iotlb_lock); + while (len > s) { u64 size, pa, pfn; @@ -1103,6 +1105,8 @@ static int iotlb_translate(const struct vringh *vrh, ++ret; } + spin_unlock(vrh->iotlb_lock); + return ret; } @@ -1262,10 +1266,13 @@ EXPORT_SYMBOL(vringh_init_iotlb); * vringh_set_iotlb - initialize a vringh for a ring with IOTLB. * @vrh: the vring * @iotlb: iotlb associated with this vring + * @iotlb_lock: spinlock to synchronize the iotlb accesses */ -void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb) +void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb, + spinlock_t *iotlb_lock) { vrh->iotlb = iotlb; + vrh->iotlb_lock = iotlb_lock; } EXPORT_SYMBOL(vringh_set_iotlb);