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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED, USER_AGENT_GIT 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 5F84CC28CC5 for ; Wed, 5 Jun 2019 23:44:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3838320717 for ; Wed, 5 Jun 2019 23:44:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="MHtX30vw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726830AbfFEXoi (ORCPT ); Wed, 5 Jun 2019 19:44:38 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:40272 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726808AbfFEXof (ORCPT ); Wed, 5 Jun 2019 19:44:35 -0400 Received: by mail-pg1-f194.google.com with SMTP id d30so213695pgm.7 for ; Wed, 05 Jun 2019 16:44:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=O/rnPOIToTFx5TLEufnCNbUgXKKUEmLsHgR6/mZpdjU=; b=MHtX30vwaCImP+Gi+3ZHA5YFvCgatPC5P2V/vbOYhAkd3uKWFpSwfQdIMqKJ1UN9mn ubpHA9QgM0UPJc143fTWqiXbi4prMSZRarIR96MLM1tgPc563MWE5mRtsemIxnOR/+2i tvCWi/hmoOEQ3lAIw8K9OJ6Tm6wuPY1LbOh44= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=O/rnPOIToTFx5TLEufnCNbUgXKKUEmLsHgR6/mZpdjU=; b=FIlzOWS8UrhY+iVfhj190ucjhDC0t15EPpycmQ0rvF+d0Fkb22uLqYJYX9Szc+nBfG XXkxrEdiMTecBaUMnl6FBjYTv3s2TwCGjxcahPhSLex5AVb2HAn0qi/5eTWAECS7lFFZ pWmPiUHNSXXEOa0uY+Rty/CrpIA5MkeJL4s4EbVcxlCilv9SuSCLQcGhv4Cw7IWHdJw1 UlFpfNZYOWP40b2yBha9l9JKWgpo5v45Y5NRS0rarQYlLKmFoRPD65lfGaHyKk1btvrd CFirkBhJKsP8Blz/zE5o3CDvfkc+htNa6P1ymTcAG9yY1t6dQwP44zjILOCAoWAdjJ8m /88g== X-Gm-Message-State: APjAAAWB7EtKa8Ujp42OGZXHHXfSjGONT/slDiXUIzuhBNwxc/tv2lI6 mqCqNxpnUq6jpoM0y4bZU39HCCscEsU= X-Google-Smtp-Source: APXvYqx3zG9rCLgbcYNCrxQmCKphQkBdlVy6ZRX+tG+qVBLLyEt6Kt8hYiRlUljA7AErFG1Rw0gooQ== X-Received: by 2002:aa7:824b:: with SMTP id e11mr48252024pfn.33.1559778274578; Wed, 05 Jun 2019 16:44:34 -0700 (PDT) Received: from localhost ([2620:15c:202:1:e9ae:bd45:1bd9:e60d]) by smtp.gmail.com with ESMTPSA id n13sm73547pff.59.2019.06.05.16.44.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Jun 2019 16:44:33 -0700 (PDT) From: davidriley@chromium.org To: dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Cc: David Airlie , Gerd Hoffmann , Daniel Vetter , linux-kernel@vger.kernel.org, David Riley Subject: [PATCH 4/4] drm/virtio: Add memory barriers for capset cache. Date: Wed, 5 Jun 2019 16:44:23 -0700 Message-Id: <20190605234423.11348-4-davidriley@chromium.org> X-Mailer: git-send-email 2.22.0.rc1.311.g5d7573a151-goog In-Reply-To: <20190605234423.11348-1-davidriley@chromium.org> References: <20190605234423.11348-1-davidriley@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Riley After data is copied to the cache entry, atomic_set is used indicate that the data is the entry is valid without appropriate memory barriers. Similarly the read side was missing the same memory barries. Signed-off-by: David Riley --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +++ drivers/gpu/drm/virtio/virtgpu_vq.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 88c1ed57a3c5..502f5f7c2298 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -542,6 +542,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, if (!ret) return -EBUSY; + /* is_valid check must proceed before copy of the cache entry. */ + virt_rmb(); + ptr = cache_ent->caps_cache; if (copy_to_user((void __user *)(unsigned long)args->addr, ptr, size)) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index dd5ead2541c2..b974eba4fe7d 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -583,6 +583,8 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev, cache_ent->id == le32_to_cpu(cmd->capset_id)) { memcpy(cache_ent->caps_cache, resp->capset_data, cache_ent->size); + /* Copy must occur before is_valid is signalled. */ + virt_wmb(); atomic_set(&cache_ent->is_valid, 1); break; } -- 2.22.0.rc1.311.g5d7573a151-goog