From patchwork Thu Jun 26 21:35:01 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dexuan Cui X-Patchwork-Id: 4432031 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 51C71BEEAA for ; Thu, 26 Jun 2014 20:37:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6B03720381 for ; Thu, 26 Jun 2014 20:37:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C82520379 for ; Thu, 26 Jun 2014 20:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752450AbaFZUgu (ORCPT ); Thu, 26 Jun 2014 16:36:50 -0400 Received: from p3plsmtps2ded04.prod.phx3.secureserver.net ([208.109.80.198]:39822 "EHLO p3plsmtps2ded04.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752245AbaFZUf1 (ORCPT ); Thu, 26 Jun 2014 16:35:27 -0400 Received: from linuxonhyperv.com ([72.167.245.219]) by p3plsmtps2ded04.prod.phx3.secureserver.net with : DED : id K8bS1o01R4kklxU018bSu1; Thu, 26 Jun 2014 13:35:26 -0700 x-originating-ip: 72.167.245.219 Received: by linuxonhyperv.com (Postfix, from userid 518) id 6E06B19083A; Thu, 26 Jun 2014 14:35:01 -0700 (PDT) From: Dexuan Cui To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, driverdev-devel@linuxdriverproject.org, plagnioj@jcrosoft.com, tomi.valkeinen@ti.com, linux-fbdev@vger.kernel.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com Cc: kys@microsoft.com, haiyangz@microsoft.com Subject: [PATCH v2] video: hyperv: hyperv_fb: refresh the VM screen by force on VM panic Date: Thu, 26 Jun 2014 14:35:01 -0700 Message-Id: <1403818501-15547-1-git-send-email-decui@microsoft.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently the VSC has no chance to notify the VSP of the dirty rectangle on VM panic because the notification work is done in a workqueue, and in panic() the kernel typically ends up in an infinite loop, and a typical kernel config has CONFIG_PREEMPT_VOLUNTARY=y and CONFIG_PREEMPT is not set, so a context switch can't happen in panic() and the workqueue won't have a chance to run. As a result, the VM Connection window can't refresh until it's closed and we re-connect to the VM. We can register a handler on panic_notifier_list: the handler can notify the VSC and switch the framebuffer driver to a "synchronous mode", meaning the VSC flushes any future framebuffer change to the VSP immediately. v2: removed the MS-TFS line in the commit message Signed-off-by: Dexuan Cui Reviewed-by: Haiyang Zhang --- drivers/video/fbdev/hyperv_fb.c | 58 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 3 deletions(-) diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index e23392e..291d171 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -226,11 +226,16 @@ struct hvfb_par { u8 recv_buf[MAX_VMBUS_PKT_SIZE]; }; +static struct fb_info *hvfb_info; + static uint screen_width = HVFB_WIDTH; static uint screen_height = HVFB_HEIGHT; static uint screen_depth; static uint screen_fb_size; +/* If true, the VSC notifies the VSP on every framebuffer change */ +static bool synchronous_fb; + /* Send message to Hyper-V host */ static inline int synthvid_send(struct hv_device *hdev, struct synthvid_msg *msg) @@ -532,6 +537,20 @@ static void hvfb_update_work(struct work_struct *w) schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY); } +static int hvfb_on_panic(struct notifier_block *nb, + unsigned long e, void *p) +{ + if (hvfb_info) + synthvid_update(hvfb_info); + + synchronous_fb = true; + + return NOTIFY_DONE; +} + +static struct notifier_block hvfb_panic_nb = { + .notifier_call = hvfb_on_panic, +}; /* Framebuffer operation handlers */ @@ -582,14 +601,41 @@ static int hvfb_blank(int blank, struct fb_info *info) return 1; /* get fb_blank to set the colormap to all black */ } +static void hvfb_cfb_fillrect(struct fb_info *p, + const struct fb_fillrect *rect) +{ + cfb_fillrect(p, rect); + + if (unlikely(synchronous_fb)) + synthvid_update(p); +} + +static void hvfb_cfb_copyarea(struct fb_info *p, + const struct fb_copyarea *area) +{ + cfb_copyarea(p, area); + + if (unlikely(synchronous_fb)) + synthvid_update(p); +} + +static void hvfb_cfb_imageblit(struct fb_info *p, + const struct fb_image *image) +{ + cfb_imageblit(p, image); + + if (unlikely(synchronous_fb)) + synthvid_update(p); +} + static struct fb_ops hvfb_ops = { .owner = THIS_MODULE, .fb_check_var = hvfb_check_var, .fb_set_par = hvfb_set_par, .fb_setcolreg = hvfb_setcolreg, - .fb_fillrect = cfb_fillrect, - .fb_copyarea = cfb_copyarea, - .fb_imageblit = cfb_imageblit, + .fb_fillrect = hvfb_cfb_fillrect, + .fb_copyarea = hvfb_cfb_copyarea, + .fb_imageblit = hvfb_cfb_imageblit, .fb_blank = hvfb_blank, }; @@ -801,6 +847,9 @@ static int hvfb_probe(struct hv_device *hdev, par->fb_ready = true; + hvfb_info = info; + atomic_notifier_chain_register(&panic_notifier_list, &hvfb_panic_nb); + return 0; error: @@ -820,6 +869,9 @@ static int hvfb_remove(struct hv_device *hdev) struct fb_info *info = hv_get_drvdata(hdev); struct hvfb_par *par = info->par; + atomic_notifier_chain_unregister(&panic_notifier_list, &hvfb_panic_nb); + hvfb_info = NULL; + par->update = false; par->fb_ready = false;