From nobody Sun Feb 8 03:39:25 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8BB741487F6; Tue, 3 Jun 2025 21:01:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748984463; cv=none; b=sqNkKVl8Mp4Spsj0VEG46rl2g+aFCnOj3nTuCHLl0Q73kN+ehyaW6IH1RYTWNh1GOUaaYY4D5qndtdhpZZAM2y09qhy+J2rnam/G4qLYOX8hDOoO0EHllfy9vUpc6JmE/IJhx/jpFe7f9HkzNcAiiY2M9psNxlxHzpOPrSKo/5k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748984463; c=relaxed/simple; bh=r3jk8NiwEP5rXMWWtANPKYEXLB8GlSyHB3WwxJIHfhk=; h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=R7+bAO2B3ZJUjKqdPfu58DMhnetjUYCMObfMDoTzJrBV3bVzkZxGlWppI14qDgurWASq6AsreNUyb8ReIWdynNby3LuM2BM3LirrevcFGNuVs3qly2zttwFkzyJBYVeoGh5bKeXlVJPBQ+yIfIeRYPYpsEZXB96g/pBFWgSUflw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=ftezYUWK; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="ftezYUWK" Received: from [100.64.0.138] (unknown [52.148.171.5]) by linux.microsoft.com (Postfix) with ESMTPSA id D578C2115DB5; Tue, 3 Jun 2025 14:01:00 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D578C2115DB5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1748984461; bh=cuvZaG9YZJheHlVoHJF6wkxDezWTkCK93CTFbc8d26I=; h=Date:To:Cc:From:Subject:From; b=ftezYUWKTthPxfuQNVJBa8vgp9KUxg5cFcs59YXTg8F2GN4x8eWQ2Qator7DxCDPd nmHZFT/woaFYmroxb+XhTuavty8Q9XEBBw6Y2XU7AqlvyL4tW2FkTmd+zmNx8W2Fqm OtxYrSz3itJPqK/s7PvuzagHUBMPLiaFgfvskcMo= Message-ID: <096edaf7-cc90-42b6-aff4-c5f088574e1e@linux.microsoft.com> Date: Tue, 3 Jun 2025 14:01:00 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, ssengar@microsoft.com Cc: romank@linux.microsoft.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org, apais@microsoft.com From: Hardik Garg Subject: Subject: [PATCH v2] vmbus: retrieve connection-id from DeviceTree Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: quoted-printable The connection-id determines which hypervisor communication channel the guest should use to talk to the VMBus host. This patch adds support to read this value from the DeviceTree where it exists as a property under the vmbus node with the compatible ID "microsoft,message-connection-id". The property name follows the format , where "vendor": "microsoft" and "field": "message-connection-id" Reading from DeviceTree allows platforms to specify their preferred communication channel, making it more flexible. If the property is not found in the DeviceTree, use the default connection ID (VMBUS_MESSAGE_CONNECTION_ID or VMBUS_MESSAGE_CONNECTION_ID_4 based on protocol version). Signed-off-by: Hardik Garg --- v2: - Rebased on hyperv-next branch as requested by maintainers - Added details about the property name format in the commit message v1:=20 https://lore.kernel.org/all/6acee4bf-cb04-43b9-9476-e8d811d26dfd@linux.micr= osoft.com/ =C2=A0drivers/hv/connection.c |=C2=A0 6 ++++-- =C2=A0drivers/hv/vmbus_drv.c=C2=A0 | 13 +++++++++++++ =C2=A02 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index be490c598785..c444c943c1d4 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -99,12 +99,14 @@ int vmbus_negotiate_version(struct=20 vmbus_channel_msginfo *msginfo, u32 version) =C2=A0=C2=A0=C2=A0=C2=A0 if (version >=3D VERSION_WIN10_V5) { =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 msg->msg_sint =3D VMBUS_M= ESSAGE_SINT; =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 msg->msg_vtl =3D ms_hyper= v.vtl; -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vmbus_connection.msg_conn_id = =3D VMBUS_MESSAGE_CONNECTION_ID_4; =C2=A0=C2=A0=C2=A0=C2=A0 } else { =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 msg->interrupt_page =3D v= irt_to_phys(vmbus_connection.int_page); -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vmbus_connection.msg_conn_id = =3D VMBUS_MESSAGE_CONNECTION_ID; =C2=A0=C2=A0=C2=A0=C2=A0 } +=C2=A0=C2=A0=C2=A0 /* Set default connection ID if not provided via Device= Tree */ +=C2=A0=C2=A0=C2=A0 if (!vmbus_connection.msg_conn_id) +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vmbus_connection.msg_conn_id = =3D (version >=3D VERSION_WIN10_V5) ? +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 VMBUS_M= ESSAGE_CONNECTION_ID_4 : VMBUS_MESSAGE_CONNECTION_ID; =C2=A0=C2=A0=C2=A0=C2=A0 /* =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * shared_gpa_boundary is zero in non-SNP VM= s, so it's safe to always =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * bitwise OR it diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index c236081d0a87..6a886611c448 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -2541,10 +2541,23 @@ static int vmbus_device_add(struct=20 platform_device *pdev) =C2=A0=C2=A0=C2=A0=C2=A0 struct of_range range; =C2=A0=C2=A0=C2=A0=C2=A0 struct of_range_parser parser; =C2=A0=C2=A0=C2=A0=C2=A0 struct device_node *np =3D pdev->dev.of_node; +=C2=A0=C2=A0=C2=A0 unsigned int conn_id; =C2=A0=C2=A0=C2=A0=C2=A0 int ret; =C2=A0=C2=A0=C2=A0=C2=A0 vmbus_root_device =3D &pdev->dev; +=C2=A0=C2=A0=C2=A0 /* +=C2=A0=C2=A0=C2=A0=C2=A0 * Read connection ID from DeviceTree. The propert= y name follows the +=C2=A0=C2=A0=C2=A0=C2=A0 * format , where: +=C2=A0=C2=A0=C2=A0=C2=A0 * - vendor: "microsoft" +=C2=A0=C2=A0=C2=A0=C2=A0 * - field: "message-connection-id" +=C2=A0=C2=A0=C2=A0=C2=A0 */ +=C2=A0=C2=A0=C2=A0 ret =3D of_property_read_u32(np, "microsoft,message-con= nection-id",=20 &conn_id); +=C2=A0=C2=A0=C2=A0 if (!ret) { +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pr_info("VMBus message connecti= on ID: %u\n", conn_id); +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vmbus_connection.msg_conn_id = =3D conn_id; +=C2=A0=C2=A0=C2=A0 } + =C2=A0=C2=A0=C2=A0=C2=A0 ret =3D of_range_parser_init(&parser, np); =C2=A0=C2=A0=C2=A0=C2=A0 if (ret) =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return ret; --=20 2.40.4