From patchwork Sat Oct 3 10:02:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 11815173 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 020756CA for ; Sat, 3 Oct 2020 10:02:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7BE1206CD for ; Sat, 3 Oct 2020 10:02:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725891AbgJCKC0 convert rfc822-to-8bit (ORCPT ); Sat, 3 Oct 2020 06:02:26 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:29446 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbgJCKCX (ORCPT ); Sat, 3 Oct 2020 06:02:23 -0400 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-378-tgmJOLFBPUuJiiTYcs74xg-1; Sat, 03 Oct 2020 06:02:18 -0400 X-MC-Unique: tgmJOLFBPUuJiiTYcs74xg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E5F43185A0C1; Sat, 3 Oct 2020 10:02:16 +0000 (UTC) Received: from bahia.lan (ovpn-112-192.ams2.redhat.com [10.36.112.192]) by smtp.corp.redhat.com (Postfix) with ESMTP id C57B110013C4; Sat, 3 Oct 2020 10:02:14 +0000 (UTC) Subject: [PATCH v3 3/3] vhost: Don't call log_access_ok() when using IOTLB From: Greg Kurz To: "Michael S. Tsirkin" , Jason Wang Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Laurent Vivier , David Gibson Date: Sat, 03 Oct 2020 12:02:13 +0200 Message-ID: <160171933385.284610.10189082586063280867.stgit@bahia.lan> In-Reply-To: <160171888144.284610.4628526949393013039.stgit@bahia.lan> References: <160171888144.284610.4628526949393013039.stgit@bahia.lan> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=groug@kaod.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kaod.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When the IOTLB device is enabled, the log_guest_addr that is passed by userspace to the VHOST_SET_VRING_ADDR ioctl, and which is then written to vq->log_addr, is a GIOVA. All writes to this address are translated by log_user() to writes to an HVA, and then ultimately logged through the corresponding GPAs in log_write_hva(). No logging will ever occur with vq->log_addr in this case. It is thus wrong to pass vq->log_addr and log_guest_addr to log_access_vq() which assumes they are actual GPAs. Introduce a new vq_log_used_access_ok() helper that only checks accesses to the log for the used structure when there isn't an IOTLB device around. Signed-off-by: Greg Kurz Acked-by: Jason Wang --- drivers/vhost/vhost.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 9d2c225fb518..9ad45e1d27f0 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1370,6 +1370,20 @@ bool vhost_log_access_ok(struct vhost_dev *dev) } EXPORT_SYMBOL_GPL(vhost_log_access_ok); +static bool vq_log_used_access_ok(struct vhost_virtqueue *vq, + void __user *log_base, + bool log_used, + u64 log_addr) +{ + /* If an IOTLB device is present, log_addr is a GIOVA that + * will never be logged by log_used(). */ + if (vq->iotlb) + return true; + + return !log_used || log_access_ok(log_base, log_addr, + vhost_get_used_size(vq, vq->num)); +} + /* Verify access for write logging. */ /* Caller should have vq mutex and device mutex */ static bool vq_log_access_ok(struct vhost_virtqueue *vq, @@ -1377,8 +1391,7 @@ static bool vq_log_access_ok(struct vhost_virtqueue *vq, { return vq_memory_access_ok(log_base, vq->umem, vhost_has_feature(vq, VHOST_F_LOG_ALL)) && - (!vq->log_used || log_access_ok(log_base, vq->log_addr, - vhost_get_used_size(vq, vq->num))); + vq_log_used_access_ok(vq, log_base, vq->log_used, vq->log_addr); } /* Can we start vq? */ @@ -1517,9 +1530,9 @@ static long vhost_vring_set_addr(struct vhost_dev *d, return -EINVAL; /* Also validate log access for used ring if enabled. */ - if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && - !log_access_ok(vq->log_base, a.log_guest_addr, - vhost_get_used_size(vq, vq->num))) + if (!vq_log_used_access_ok(vq, vq->log_base, + a.flags & (0x1 << VHOST_VRING_F_LOG), + a.log_guest_addr)) return -EINVAL; }