From patchwork Tue Nov 26 23:22:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Denis Mukhin via B4 Relay X-Patchwork-Id: 13886428 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 53F36D66B9A for ; Tue, 26 Nov 2024 23:38:34 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.844355.1259921 (Exim 4.92) (envelope-from ) id 1tG58X-0003qG-7b; Tue, 26 Nov 2024 23:38:29 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 844355.1259921; Tue, 26 Nov 2024 23:38:29 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tG58X-0003q9-4H; Tue, 26 Nov 2024 23:38:29 +0000 Received: by outflank-mailman (input) for mailman id 844355; Tue, 26 Nov 2024 23:38:27 +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 1tG4sn-0000At-E0 for xen-devel@lists.xenproject.org; Tue, 26 Nov 2024 23:22:13 +0000 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 3dbddc90-ac4d-11ef-99a3-01e77a169b0f; Wed, 27 Nov 2024 00:22:02 +0100 (CET) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id BDF735C5D37; Tue, 26 Nov 2024 23:21:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id E73D3C4CED3; Tue, 26 Nov 2024 23:21:56 +0000 (UTC) Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB2FED66B94; Tue, 26 Nov 2024 23:21:56 +0000 (UTC) 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: 3dbddc90-ac4d-11ef-99a3-01e77a169b0f X-Custom-Connection: eyJyZW1vdGVpcCI6IjEzOS4xNzguODQuMjE3IiwiaGVsbyI6ImRmdy5zb3VyY2Uua2VybmVsLm9yZyJ9 X-Custom-Transaction: eyJpZCI6IjNkYmRkYzkwLWFjNGQtMTFlZi05OWEzLTAxZTc3YTE2OWIwZiIsInRzIjoxNzMyNjYzMzIzLjE4OTI5Niwic2VuZGVyIjoiZGV2bnVsbCtkbXVraGluLmZvcmQuY29tQGtlcm5lbC5vcmciLCJyZWNpcGllbnQiOiJ4ZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcifQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1732663317; bh=Msd9ALOQsKWgqYjqZp3vEbU4YxKp+IL/6j5doF/TX4s=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=EjGuXXXvARbSkfc9IeVFfmDHBQewfsHXB2SXcmmGhSEvXVTaV5iWWdnXzabgyJMwH +B5r5Dapx/vEoY/eyz5JhORRlBsB0xnQ2a8FoW5puADacIjjtYIyGkiLIhNX0HjDVC FGkTol8ab/a+6vKnUS41q9cGlMb7mjKysuc2cBgm3N4lzTYJX30pRJko+rhXJfcGYt Jj4SZkbqShKLlqH01xPdfnHWxkxZmXo8hYKCjcawD/AMa7gR9MxMJ7XEfM0gASX3E7 dNFMElmgkVxhKRPxT/vr/jXLwNXBsQBhZsjfCtbRCdQY63rpKkATQiAhj3RupE5tkt rldH3hv+7xf/Q== From: Denis Mukhin via B4 Relay Date: Tue, 26 Nov 2024 15:22:12 -0800 Subject: [PATCH 22/36] xen/console: introduce console_set_owner() MIME-Version: 1.0 Message-Id: <20241126-vuart-ns8250-v1-v1-22-87b9a8375b7a@ford.com> References: <20241126-vuart-ns8250-v1-v1-0-87b9a8375b7a@ford.com> In-Reply-To: <20241126-vuart-ns8250-v1-v1-0-87b9a8375b7a@ford.com> To: Jan Beulich , Andrew Cooper , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , "Daniel P. Smith" , Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Rahul Singh , Volodymyr Babchuk , Alistair Francis , Bob Eshleman , Connor Davis , Oleksii Kurochko , Shawn Anastasio , Anthony PERARD , Juergen Gross , Christian Lindig , David Scott , =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= Cc: xen-devel@lists.xenproject.org, Denis Mukhin X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1732663312; l=6105; i=dmukhin@ford.com; s=20241125; h=from:subject:message-id; bh=LaoLtTtPVB803Wx66ywoNWCuGefL+9P7BcXWkOi4Ttw=; b=4lK/8BHVyfy3woSRpKh5PM02ENnqP+ItqkfEgYigMPj6lRFJWcPJsSQvqyG1yASQpUrz6O30O flL6r/RmuUgA0bIlRawQx23oGAn7Yvbn6WD6FIZY6jvjVBKaIN+E4lv X-Developer-Key: i=dmukhin@ford.com; a=ed25519; pk=SsDZ9p39s0fqcpUKQuqKqrbn0rq6EtEAClvpOpzx6+U= X-Endpoint-Received: by B4 Relay for dmukhin@ford.com/20241125 with auth_id=287 X-Original-From: Denis Mukhin Reply-To: dmukhin@ford.com From: Denis Mukhin console_set_owner() is introduced for setting the new console owner. Switches console owner to domain ID vs range of integer numbers mapped to domain IDs. This a public API to console driver, will be used in the follow on code change. Signed-off-by: Denis Mukhin --- xen/drivers/char/console.c | 122 ++++++++++++++++++++++++++------------------- xen/include/xen/console.h | 1 + 2 files changed, 71 insertions(+), 52 deletions(-) diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index 8cbac54c66044ae8581e486a782102b75c8bfaa9..52cf64dbf6fd18d599cb88835d03501a23b3e3c4 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -463,82 +463,100 @@ static void cf_check dump_console_ring_key(unsigned char key) /* * CTRL- changes input direction, rotating among Xen, Dom0, - * and the DomUs started from Xen at boot. + * and the DomUs. */ #define switch_code (opt_conswitch[0]-'a'+1) + /* - * console_owner=0 => input to xen - * console_owner=1 => input to dom0 (or the sole shim domain) - * console_owner=N => input to dom(N-1) + * Current console owner domain ID: either Xen or domain w/ d->is_console == + * true. + * + * Initialized in console_endboot(). */ -static unsigned int __read_mostly console_owner = 0; +static domid_t __read_mostly console_owner; -#define max_console_rx (max_init_domid + 1) +static struct domain *rcu_lock_domain_console_by_id(domid_t domid) +{ + struct domain *d; + + d = rcu_lock_domain_by_id(domid); + + if ( d == NULL ) + return NULL; + + if ( d->is_console ) + return d; + + rcu_unlock_domain(d); + + return NULL; +} -#ifdef CONFIG_SBSA_VUART_CONSOLE /* Make sure to rcu_unlock_domain after use */ struct domain *rcu_lock_domain_console_owner(void) { - if ( console_owner == 0 ) - return NULL; - return rcu_lock_domain_by_id(console_owner - 1); + return rcu_lock_domain_console_by_id(console_owner); } -#endif -static void console_find_owner(void) +static bool console_owner_possible(domid_t domid) { - unsigned int next_rx = console_owner; - - /* - * Rotate among Xen, dom0 and boot-time created domUs while skipping - * switching serial input to non existing domains. - */ - for ( ; ; ) - { - domid_t domid; - struct domain *d; - - if ( next_rx++ >= max_console_rx ) - { - console_owner = 0; - printk("*** Serial input to Xen"); - break; - } - - if ( consoled_is_enabled() && next_rx == 1 ) - domid = get_initial_domain_id(); - else - domid = next_rx - 1; - - d = rcu_lock_domain_by_id(domid); - if ( d == NULL ) - continue; - - if ( d->is_console ) - { - rcu_unlock_domain(d); - console_owner = next_rx; - printk("*** Serial input to DOM%u", domid); - break; - } + struct domain *d; + d = rcu_lock_domain_console_by_id(domid); + if ( d != NULL ) rcu_unlock_domain(d); - } + + return d != NULL; +} + +int console_set_owner(domid_t domid) +{ + if ( domid == DOMID_XEN ) + printk("*** Serial input to Xen"); + else if ( console_owner_possible(domid) ) + printk("*** Serial input to DOM%u", domid); + else + return -ENOENT; + + console_owner = domid; if ( switch_code ) printk(" (type 'CTRL-%c' three times to switch input)", opt_conswitch[0]); printk("\n"); + + return 0; +} + +/* + * Switch console input focus. + * Rotates input focus among Xen, dom0 and boot-time created domUs while + * skipping switching serial input to non existing domains. + */ +static void console_find_owner(void) +{ + domid_t i, n = max_init_domid + 1; + + if ( console_owner == DOMID_XEN ) + i = get_initial_domain_id(); + else + i = console_owner + 1; + + for ( ; i < n; i++ ) + if ( !console_set_owner(i) ) + break; + if ( i == n ) + console_set_owner(DOMID_XEN); } static void __serial_rx(char c) { switch ( console_owner ) { - case 0: + case DOMID_XEN: return handle_keypress(c, false); - case 1: + case 0: /* * Deliver input to the hardware domain buffer, unless it is * already full. @@ -556,7 +574,7 @@ static void __serial_rx(char c) #ifdef CONFIG_SBSA_VUART_CONSOLE default: { - struct domain *d = rcu_lock_domain_by_id(console_owner - 1); + struct domain *d = rcu_lock_domain_by_id(console_owner); /* * If we have a properly initialized vpl011 console for the @@ -567,7 +585,7 @@ static void __serial_rx(char c) vpl011_rx_char_xen(d, c); else printk("Cannot send chars to Dom%d: no UART available\n", - console_owner - 1); + console_owner); if ( d != NULL ) rcu_unlock_domain(d); @@ -1126,7 +1144,7 @@ void __init console_endboot(void) * a useful 'how to switch' message. */ if ( opt_conswitch[1] == 'x' ) - console_owner = max_console_rx; + console_owner = DOMID_XEN; register_keyhandler('w', dump_console_ring_key, "synchronously dump console ring buffer (dmesg)", 0); diff --git a/xen/include/xen/console.h b/xen/include/xen/console.h index 0e211e44d9703c804e18f52c9743916f8d2a9d4e..57c482cfbf2da15b011e64841ea086e779f4588d 100644 --- a/xen/include/xen/console.h +++ b/xen/include/xen/console.h @@ -32,6 +32,7 @@ void console_start_log_everything(void); void console_end_log_everything(void); struct domain *rcu_lock_domain_console_owner(void); +int console_set_owner(domid_t); /* * Steal output from the console. Returns +ve identifier, else -ve error.