From patchwork Thu Apr 3 00:06:32 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Denis Mukhin X-Patchwork-Id: 14036618 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A585C36018 for ; Thu, 3 Apr 2025 00:06:52 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.936150.1337476 (Exim 4.92) (envelope-from ) id 1u086S-0002aq-De; Thu, 03 Apr 2025 00:06:40 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 936150.1337476; Thu, 03 Apr 2025 00:06:40 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u086S-0002aj-8e; Thu, 03 Apr 2025 00:06:40 +0000 Received: by outflank-mailman (input) for mailman id 936150; Thu, 03 Apr 2025 00:06:39 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1u086R-000234-AB for xen-devel@lists.xenproject.org; Thu, 03 Apr 2025 00:06:39 +0000 Received: from mail-4316.protonmail.ch (mail-4316.protonmail.ch [185.70.43.16]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 830b6832-101f-11f0-9ffb-bf95429c2676; Thu, 03 Apr 2025 02:06:37 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 830b6832-101f-11f0-9ffb-bf95429c2676 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=lluhb2firrddhpi264e3pc4bsy.protonmail; t=1743638797; x=1743897997; bh=GYrF79Lky+t8pJBLpkLDqHS5mjT9sR3p7CaY+cQEX88=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector:List-Unsubscribe:List-Unsubscribe-Post; b=GjjTpaza1P+1T0MBPu3LhQ4JPYAc/JiUfL5MOerA+xFcmNwv6vGJit7Ht90Kshu/I K3EWULEH/Pz8AaYQAjS3CbXlzavFt5Tbs7ZMFz8aQ7hPSuBcLzyPmo34WFPUxeOZCi Txoy3EEzjK5fGMlwGyc7gTSOSBsj8hwcNJ1nIMueHRWq8OYycYlspL8xCAg6yQMrAV gnp5mtxlebkEZ+/sElzxhJW+TsKkFMlfB1umiEiNlr6hgBGg+VMOhCqdlsv2PMLC7D dc3hguy/FuQ4XnkFitHEOwOrTf7RO0lnHK3MO1wYLIJN4NqoXkPpMIVOj6x6aaa+Ab T8OQvn3y1i2JA== Date: Thu, 03 Apr 2025 00:06:32 +0000 To: xen-devel@lists.xenproject.org From: dmkhn@proton.me Cc: andrew.cooper3@citrix.com, anthony.perard@vates.tech, jbeulich@suse.com, julien@xen.org, michal.orzel@amd.com, roger.pau@citrix.com, sstabellini@kernel.org, dmukhin@ford.com Subject: [PATCH v1 3/3] xen/console: introduce conring_flush() Message-ID: <20250403000604.169619-4-dmukhin@ford.com> In-Reply-To: <20250403000604.169619-1-dmukhin@ford.com> References: <20250403000604.169619-1-dmukhin@ford.com> Feedback-ID: 123220910:user:proton X-Pm-Message-ID: 9f9887882ae5bbc02fc76b68206c9230209cbb57 MIME-Version: 1.0 From: Denis Mukhin Introduce conring_flush() to ensure all messages kept in the internal console ring are sent to all physical consoles (serial, VGA (x86)) after their initialization is completed. Resolves: https://gitlab.com/xen-project/xen/-/issues/184 Signed-off-by: Denis Mukhin --- The patch conflicts with https://lore.kernel.org/xen-devel/20250331230508.440198-7-dmukhin@ford.com/ in console_init_preirq() --- xen/drivers/char/console.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index 2618c2e47d..18eb66df89 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -446,24 +446,22 @@ void console_serial_puts(const char *s, size_t nr) serial_puts(sercon_handle, s, nr); } -static void cf_check dump_console_ring_key(unsigned char key) +/* + * Flush contents of the conring to the physical console devices. + */ +static int conring_flush(void) { uint32_t idx, len, sofar, c; unsigned int order; char *buf; + unsigned long flags; - printk("'%c' pressed -> dumping console ring buffer (dmesg)\n", key); - - /* create a buffer in which we'll copy the ring in the correct - order and NUL terminate */ order = get_order_from_bytes(conring_size + 1); buf = alloc_xenheap_pages(order, 0); if ( buf == NULL ) - { - printk("unable to allocate memory!\n"); - return; - } + return -ENOMEM; + flags = console_lock_recursive_irqsave(); c = conringc; sofar = 0; while ( (c != conringp) ) @@ -478,8 +476,21 @@ static void cf_check dump_console_ring_key(unsigned char key) } console_puts(buf, sofar, CONSOLE_SERIAL | CONSOLE_VIDEO | CONSOLE_PV); + console_unlock_recursive_irqrestore(flags); free_xenheap_pages(buf, order); + + return 0; +} + +static void cf_check conring_dump_keyhandler(unsigned char key) +{ + int rc; + + printk("'%c' pressed -> dumping console ring buffer (dmesg)\n", key); + rc = conring_flush(); + if ( rc ) + printk("failed to dump console ring buffer: %d\n", rc); } /* @@ -1044,6 +1055,9 @@ void __init console_init_preirq(void) serial_set_rx_handler(sercon_handle, serial_rx); pv_console_set_rx_handler(serial_rx); + /* NB: send conring contents to all enabled physical consoles, if any */ + conring_flush(); + /* HELLO WORLD --- start-of-day banner text. */ nrspin_lock(&console_lock); __putstr(xen_banner()); @@ -1134,7 +1148,7 @@ void __init console_endboot(void) if ( opt_conswitch[1] == 'x' ) console_rx = max_console_rx; - register_keyhandler('w', dump_console_ring_key, + register_keyhandler('w', conring_dump_keyhandler, "synchronously dump console ring buffer (dmesg)", 0); register_irq_keyhandler('+', &do_inc_thresh, "increase log level threshold", 0);