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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 6C352C169C4 for ; Fri, 8 Feb 2019 14:04:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3830620857 for ; Fri, 8 Feb 2019 14:04:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727677AbfBHOEO (ORCPT ); Fri, 8 Feb 2019 09:04:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41352 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726600AbfBHOEO (ORCPT ); Fri, 8 Feb 2019 09:04:14 -0500 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 mx1.redhat.com (Postfix) with ESMTPS id A15C959479; Fri, 8 Feb 2019 14:04:13 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-117-137.ams2.redhat.com [10.36.117.137]) by smtp.corp.redhat.com (Postfix) with ESMTP id A48391048125; Fri, 8 Feb 2019 14:04:10 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id C8EE4A1E3; Fri, 8 Feb 2019 15:04:09 +0100 (CET) From: Gerd Hoffmann To: dri-devel@lists.freedesktop.org, David Airlie Cc: Gerd Hoffmann , David Airlie , Daniel Vetter , virtualization@lists.linux-foundation.org (open list:VIRTIO GPU DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] drm/virtio: do NOT reuse resource ids Date: Fri, 8 Feb 2019 15:04:09 +0100 Message-Id: <20190208140409.15280-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 08 Feb 2019 14:04:14 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bisected guest kernel changes crashing qemu. Landed at "6c1cd97bda drm/virtio: fix resource id handling". Looked again, and noticed we where not only leaking *some* ids, but *all* ids. The old code never ever called virtio_gpu_resource_id_put(). So, commit 6c1cd97bda effectively makes the linux kernel starting re-using IDs after releasing them, and apparently virglrenderer can't deal with that. Oops. This patch puts a temporary stopgap into place for the 5.0 release. Cc: David Airlie Signed-off-by: Gerd Hoffmann --- Notes: Hi Dave, I'll be offline next week, so please commit to drm-next-fixes if you think this patch is acceptable. drivers/gpu/drm/virtio/virtgpu_object.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index f39a183d59..e7e9460350 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -28,10 +28,21 @@ static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev, uint32_t *resid) { +#if 0 int handle = ida_alloc(&vgdev->resource_ida, GFP_KERNEL); if (handle < 0) return handle; +#else + static int handle; + + /* + * FIXME: dirty hack to avoid re-using IDs, virglrenderer + * can't deal with that. Needs fixing in virglrenderer, also + * should figure a better way to handle that in the guest. + */ + handle++; +#endif *resid = handle + 1; return 0; @@ -39,7 +50,9 @@ static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev, static void virtio_gpu_resource_id_put(struct virtio_gpu_device *vgdev, uint32_t id) { +#if 0 ida_free(&vgdev->resource_ida, id - 1); +#endif } static void virtio_gpu_ttm_bo_destroy(struct ttm_buffer_object *tbo) -- 2.9.3