From patchwork Fri Oct 20 16:15:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 736536 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDD8BC07480 for ; Fri, 20 Oct 2023 16:16:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377804AbjJTQQD (ORCPT ); Fri, 20 Oct 2023 12:16:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229814AbjJTQQB (ORCPT ); Fri, 20 Oct 2023 12:16:01 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB9F8D57; Fri, 20 Oct 2023 09:15:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description; bh=OW6M6axVm5EebrjONkYC4l2vPrYg1mjhksi3LsyyGRs=; b=EMC1XQKNq6loHyWtwUrjbzwmwV cAgfQRMd4tmkJ8vfgqiDsAHkfDsIEKFYNphoGgZltm07MeMmeMyO41dK4BLYlKHBUnL8cqRNJUffv zVUHHvzr6M4MMJHsTleqmotIfBWN5RE5+FHp2NiKmK8ql6L7KcoxAfQIzazUnV+8qIv//5YmJyAH9 OxkBx/FtKdKWlxLO5fHYVYMBiLVYGrhC5A2L6h+uGalAtARfBXqSpuBlQovufA2ZACvU44sInMHHX saBDt/gndB0Jsk/Udp6oA3ydy0qG4OQ/poadbKKrrsFCSauxFUH/o6H3FX9ha6MDCtAaqPZVCLSsN QtrjJRcw==; Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qts9v-00BAsE-0Q; Fri, 20 Oct 2023 16:15:36 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qts9s-001UOW-0m; Fri, 20 Oct 2023 17:15:32 +0100 From: David Woodhouse To: Juergen Gross , xen-devel@lists.xenproject.org Cc: Greg Kroah-Hartman , Jiri Slaby , Roger Pau Monne , Stefano Stabellini , Dawei Li , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Paul Durrant Subject: [PATCH v2 1/3] hvc/xen: fix event channel handling for secondary consoles Date: Fri, 20 Oct 2023 17:15:27 +0100 Message-Id: <20231020161529.355083-2-dwmw2@infradead.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231020161529.355083-1-dwmw2@infradead.org> References: <20231020161529.355083-1-dwmw2@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: David Woodhouse The xencons_connect_backend() function allocates a local interdomain event channel with xenbus_alloc_evtchn(), then calls bind_interdomain_evtchn_to_irq_lateeoi() to bind to that port# on the *remote* domain. That doesn't work very well: (qemu) device_add xen-console,id=con1,chardev=pty0 [ 44.323872] xenconsole console-1: 2 xenbus_dev_probe on device/console/1 [ 44.323995] xenconsole: probe of console-1 failed with error -2 Fix it to use bind_evtchn_to_irq_lateeoi(), which does the right thing by just binding that *local* event channel to an irq. The backend will do the interdomain binding. This didn't affect the primary console because the setup for that is special — the toolstack allocates the guest event channel and the guest discovers it with HVMOP_get_param. Fixes: fe415186b4 ("xen/console: harden hvc_xen against event channel storms") Signed-off-by: David Woodhouse Reviewed-by: Juergen Gross Cc: stable@vger.kernel.org --- drivers/tty/hvc/hvc_xen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 98764e740c07..f24e285b6441 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -433,7 +433,7 @@ static int xencons_connect_backend(struct xenbus_device *dev, if (ret) return ret; info->evtchn = evtchn; - irq = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn); + irq = bind_evtchn_to_irq_lateeoi(evtchn); if (irq < 0) return irq; info->irq = irq; From patchwork Fri Oct 20 16:15:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 736537 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6CB3CDB474 for ; Fri, 20 Oct 2023 16:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229755AbjJTQPz (ORCPT ); Fri, 20 Oct 2023 12:15:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229733AbjJTQPy (ORCPT ); Fri, 20 Oct 2023 12:15:54 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 921C6114; Fri, 20 Oct 2023 09:15:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description; bh=I4hMGAn3CCXbvIhFniLsRuw1X84vM7LzNgk6oVf6hDo=; b=g6XL6KrLFvXCVI21u1A5KeupFv +QFnHNBtXPSX2WGx/qzbR8hAv15UjjS3G7GeUcRbT6Gzod96JethLXROgfY3uc2SU169IvhiZdRGh PQGKjDFv0/nWu/OIs7h5I+YdQjcKmWPq6iD07vRG6QQQEc9KMRwcxd9MEFfDm+JhqgzS/494qQBHg cmRRbbr+caoCft14R2moMfBDrzAlzzoBVVkfYfN3hN7MnKJVzuTCxV7GKaf92411iUcMwW41EdBZu LzyJ/6kNrv4xSgCoDDiOqDloTvQ2En//Zuw6p8kbzieBn/ZS50xuBKNEiKD53bPkfqRtyRa8Wwy2S MoYvVmXQ==; Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qts9u-00E44C-84; Fri, 20 Oct 2023 16:15:34 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qts9s-001UOZ-13; Fri, 20 Oct 2023 17:15:32 +0100 From: David Woodhouse To: Juergen Gross , xen-devel@lists.xenproject.org Cc: Greg Kroah-Hartman , Jiri Slaby , Roger Pau Monne , Stefano Stabellini , Dawei Li , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Paul Durrant Subject: [PATCH v2 2/3] hvc/xen: fix error path in xen_hvc_init() to always register frontend driver Date: Fri, 20 Oct 2023 17:15:28 +0100 Message-Id: <20231020161529.355083-3-dwmw2@infradead.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231020161529.355083-1-dwmw2@infradead.org> References: <20231020161529.355083-1-dwmw2@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: David Woodhouse The xen_hvc_init() function should always register the frontend driver, even when there's no primary console — as there may be secondary consoles. (Qemu can always add secondary consoles, but only the toolstack can add the primary because it's special.) Signed-off-by: David Woodhouse Reviewed-by: Juergen Gross Cc: stable@vger.kernel.org --- drivers/tty/hvc/hvc_xen.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index f24e285b6441..4a768b504263 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -588,7 +588,7 @@ static int __init xen_hvc_init(void) ops = &dom0_hvc_ops; r = xen_initial_domain_console_init(); if (r < 0) - return r; + goto register_fe; info = vtermno_to_xencons(HVC_COOKIE); } else { ops = &domU_hvc_ops; @@ -597,7 +597,7 @@ static int __init xen_hvc_init(void) else r = xen_pv_console_init(); if (r < 0) - return r; + goto register_fe; info = vtermno_to_xencons(HVC_COOKIE); info->irq = bind_evtchn_to_irq_lateeoi(info->evtchn); @@ -622,6 +622,7 @@ static int __init xen_hvc_init(void) } r = 0; + register_fe: #ifdef CONFIG_HVC_XEN_FRONTEND r = xenbus_register_frontend(&xencons_driver); #endif