From nobody Tue Feb 10 11:16:07 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1757114875; cv=none; d=zohomail.com; s=zohoarc; b=K1/nIlgg2+1u9RrzFDLcNO64CFoICBpFPVAT+OZLKmUS31HiuUCbX6+3d3N/v2vMs/HPtYUxDHrHsXGRu5xFwD9VvzTwLHrnumjtrSqxhpyj8k1dEcUSMXwPeIu6Y2UdTG+8TIrmrwhrFRIYt2Uu7CRzZNwJyVqdx8CMJ2AHJ+I= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1757114875; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=UmQzHfQSoeUK3EyjGre7Frz+a/7pj0V41RdQZawNalI=; b=JzbJ4txwIdvN50YV0Us++j/HSdhj+pEOsDzE2wbqwKcMqreS0ljCxGdOW/pSpDLkiabMkJ+gycWo+4bOPfn54sUzJXUZ90xcZ2mV79Iar+863O+L8vKjIOcwoye3/YVusAHyHbmCAqDpRtC0iRb/uwveRQxQyEbsCHzU75osz6k= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 17571148756263.223161562486098; Fri, 5 Sep 2025 16:27:55 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1112633.1460873 (Exim 4.92) (envelope-from ) id 1uufq3-0002P9-0T; Fri, 05 Sep 2025 23:27:27 +0000 Received: by outflank-mailman (output) from mailman id 1112633.1460873; Fri, 05 Sep 2025 23:27:26 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uufq2-0002OF-Ss; Fri, 05 Sep 2025 23:27:26 +0000 Received: by outflank-mailman (input) for mailman id 1112633; Fri, 05 Sep 2025 23:27:24 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uufq0-00020R-Ld for xen-devel@lists.xenproject.org; Fri, 05 Sep 2025 23:27:24 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.96) (envelope-from ) id 1uufpz-008AB8-3C; Fri, 05 Sep 2025 23:27:24 +0000 Received: from [19.12.91.86] (helo=localhost) by xenbits.xenproject.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uufpz-0005D6-39; Fri, 05 Sep 2025 23:27:24 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version 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" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From; bh=UmQzHfQSoeUK3EyjGre7Frz+a/7pj0V41RdQZawNalI=; b=R2Ldlmao5TsX5jjH26E1hrRT+N fMqbNTrmUfZ9T+vahssMVk1I9wk0stagNbzZ6DCviCCfeZb4u0t6FBRdOt+tKqkYsqbbru/Llh7DP Fythg9UWdSIP0tz8R34kAsVn6P5yLMoP8nXHDHYMcs+NeC3A5HE/lCra8LrjRjR6T8EA=; From: dmukhin@xen.org To: xen-devel@lists.xenproject.org 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 v6 05/15] emul/ns16x50: implement SCR register Date: Fri, 5 Sep 2025 16:27:04 -0700 Message-ID: <20250905232715.440758-6-dmukhin@ford.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250905232715.440758-1-dmukhin@ford.com> References: <20250905232715.440758-1-dmukhin@ford.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @xen.org) X-ZM-MESSAGEID: 1757114876429116600 Content-Type: text/plain; charset="utf-8" From: Denis Mukhin =20 Add SCR register emulation to the I/O port handler. Firmware (e.g. OVMF) may use SCR during the guest OS boot. Signed-off-by: Denis Mukhin Reviewed-by: Stefano Stabellini --- Changes since v5: - moved earlier in the series to simplify I/O handler population in the follow on patches - Link to v5: https://lore.kernel.org/xen-devel/20250828235409.2835815-11-d= mukhin@ford.com/ --- xen/common/emul/vuart/ns16x50.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/xen/common/emul/vuart/ns16x50.c b/xen/common/emul/vuart/ns16x5= 0.c index 7f479a5be4a2..51ec85e57627 100644 --- a/xen/common/emul/vuart/ns16x50.c +++ b/xen/common/emul/vuart/ns16x50.c @@ -103,6 +103,20 @@ static int ns16x50_io_write8( =20 if ( ns16x50_dlab_get(vdev) && (reg =3D=3D UART_DLL || reg =3D=3D UART= _DLM) ) regs[NS16X50_REGS_NUM + reg] =3D val; + else + { + switch ( reg ) + { + /* NB: Firmware (e.g. OVMF) may rely on SCR presence. */ + case UART_SCR: + regs[UART_SCR] =3D val; + break; + + default: + rc =3D -EINVAL; + break; + } + } =20 return rc; } @@ -165,6 +179,19 @@ static int ns16x50_io_read8( =20 if ( ns16x50_dlab_get(vdev) && (reg =3D=3D UART_DLL || reg =3D=3D UART= _DLM) ) val =3D regs[NS16X50_REGS_NUM + reg]; + else + { + switch ( reg ) + { + case UART_SCR: + val =3D regs[UART_SCR]; + break; + + default: + rc =3D -EINVAL; + break; + } + } =20 *data =3D val; =20 --=20 2.51.0