From nobody Mon Feb 9 07:23:51 2026 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75D8A320CCE; Mon, 22 Dec 2025 10:12:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766398377; cv=none; b=qgZNCxOQa9KEWiIYqQ3v6s52hRnIs60iaaR10ejMx15PCB7+sdsJqZ9ceAy6DdmxhM4kOTLRHq2aPBS18cEq5VLqTfg4VRMxPHqZ2trObS6mbo9BEoXCoiwothLGTXae/wqkqPkOjmSU0uIm8Yp6NXgVhnY+QmhB99FKTvdQJKA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766398377; c=relaxed/simple; bh=CQ0/S/9cst10jdT1raGe+Cbx3RfiJmqTSkt4++S4h+c=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PYodNnh1TQJwobJ8ig8gzuqFzSRjgsGEyZBSTDTNlx37f65vIa5AJ6kBpC8WkpRJ8iu39CCNZnaQ2z5XenhK+Oxw0TeTv38A9/HjflQg/8EP0RJxKTaP4V2uFkEaUn3bp14POP7OwCRBBEuSZqJp8EhnjrsBzfcsTAtp6r9do6A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=01U2YD76; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="01U2YD76" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 9043F1A2375; Mon, 22 Dec 2025 10:12:53 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 66AAE606C1; Mon, 22 Dec 2025 10:12:53 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 05F5B10AB0194; Mon, 22 Dec 2025 11:12:50 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1766398372; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=q2BZJOx9U840k1P5Q6/3KlepJkyEYaoPhkPZJmzsmow=; b=01U2YD76sGykg2VkPzEGsjuemDKyUX/nOij7eFZ21tH0L1TzDOi/ZztllnW904/iDICeDd nO6Q4fYAIxhQYCZlQyZAiSJlUrfI0gByiRVeU/WMCqUNk02WWJPM9xw5heFCgX8kUmjiwy tbdRcF/6Be/AUuXWC0t9fXeIiOwN5zrZ7sqQku0uzx5856ha2e5/+fU2QOvmAC92zBgVOC 9p7P+/A8mIVF7uX6art4XZGNZJD2THccnqLz1MtlLoVPUTlH0XVlJjO9ClI8rSA3ASHkQk f5CIq9O19U+hQELqt+qYeR4JNkq/h1YI9gEtyiYsPW995Z0ONJphyV+4PCCnLQ== From: Louis Chauvet Date: Mon, 22 Dec 2025 11:11:35 +0100 Subject: [PATCH v3 33/33] drm/vkms: Introduce configfs for dynamic connector creation Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20251222-vkms-all-config-v3-33-ba42dc3fb9ff@bootlin.com> References: <20251222-vkms-all-config-v3-0-ba42dc3fb9ff@bootlin.com> In-Reply-To: <20251222-vkms-all-config-v3-0-ba42dc3fb9ff@bootlin.com> To: Haneen Mohammed , Simona Vetter , Melissa Wen , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , jose.exposito89@gmail.com, Jonathan Corbet Cc: victoria@system76.com, sebastian.wick@redhat.com, victoria@system76.com, airlied@gmail.com, thomas.petazzoni@bootlin.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Louis Chauvet X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=10962; i=louis.chauvet@bootlin.com; h=from:subject:message-id; bh=CQ0/S/9cst10jdT1raGe+Cbx3RfiJmqTSkt4++S4h+c=; b=owEBiQJ2/ZANAwAIASCtLsZbECziAcsmYgBpSRlEw/pra8T5+J3MllZF8PGGe07wusZVgV3rr A8zyNI3r4eJAk8EAAEIADkWIQRPj7g/vng8MQxQWQQgrS7GWxAs4gUCaUkZRBsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMSwyLDIACgkQIK0uxlsQLOKdLRAAv21o8SPMt0Z47ubtncuoajRboLFBK6V t9KY8+WUbkd5wf6ipRnLbrilFFR5kKj5RrIUnqwxabgYrpKQZ6Be2opJeVhzW95mzFz2dqm4+TT GQxMMrG6qHl9qyw34cjJZu2d1PFuN6wpM4bCcEVhqfd2/wJTvgM48XOO5GUgJoK6ZeZ0KRetxnl STIh3WAo7GKDgWxkrC3540ecsXBHaPBTcUm358RCh0eLJJkXhq4nY9jMxz8LG6r3d1Q34kUc90+ ejA+Lijs3FBC8Fueb59UzHnFxvi7b1GvePRSY/ozw+Al0PeiLZcx7JRwqZ6/eY4QYSETYRtSgLp AMAqymzT9bVNNcDIpe+Xul7Bd15GPTsd1eR0igqnIzqgStwXvY9m8AYOuZtT5ik9vW/5Gd50+VR Dz/DJJcC13MwXEd9Xj+6UcMcRKDEFGAg0neM1msfHoDeBJS8qcJNHdSjlQgnq2FmErd/XghlS1O AzghHX5CbH+xnnqoQOM4W6Pihm9o5h90fJe0WS+/XWFE/RyU5mgUFvjqRZelvZmPBMrez75s4P5 18CqMh/ikmY14o9zOykQUz7MqqWTlDPn+jvqsSwAzcVNNOB0HuqRd0T5VIYadIQp6TU0B9W++v5 p5EB/wSROBo/LCZAJ1JxoB/omMxIjR1gbNM1NjRjygeqvtaeGMSg= X-Developer-Key: i=louis.chauvet@bootlin.com; a=openpgp; fpr=8B7104AE9A272D6693F527F2EC1883F55E0B40A5 X-Last-TLS-Session-Version: TLSv1.3 DRM allows the connector to be created after the device. To allows emulating this, add two configfs attributes to connector to allows this. Using the dynamic attribute you can set if a connector will be dynamic or not. Using the enabled attribute, you can set at runtime if a dynamic connector is present or not. Co-developed-by: Jos=C3=A9 Exp=C3=B3sito Signed-off-by: Jos=C3=A9 Exp=C3=B3sito Signed-off-by: Louis Chauvet --- Documentation/ABI/testing/configfs-vkms | 14 +++ Documentation/gpu/vkms.rst | 6 +- drivers/gpu/drm/vkms/vkms_configfs.c | 146 ++++++++++++++++++++++++++++= ++-- 3 files changed, 155 insertions(+), 11 deletions(-) diff --git a/Documentation/ABI/testing/configfs-vkms b/Documentation/ABI/te= sting/configfs-vkms index 4061ada5d88b..a7fce35fcf91 100644 --- a/Documentation/ABI/testing/configfs-vkms +++ b/Documentation/ABI/testing/configfs-vkms @@ -62,6 +62,20 @@ Description: Content of the EDID for this connector. Ignored if edid_enabled is not set. =20 +What: /sys/kernel/config/vkms//connectors//dynamic +Date: Nov 2025 +Contact: dri-devel@lists.freedesktop.org +Description: + Set to 1 to create a dynamic connector (emulates DP MST). + Value: 1 - dynamic, 0 - static. + +What: /sys/kernel/config/vkms//connectors//enabled +Date: Nov 2025 +Contact: dri-devel@lists.freedesktop.org +Description: + For dynamic connectors, set to 1 to create the connector, + 0 to remove it. Value: 1 - enabled, 0 - disabled. + What: /sys/kernel/config/vkms//connectors//possible_en= coders Date: Nov 2025 Contact: dri-devel@lists.freedesktop.org diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 60367fd1bd65..fce229fbfc7c 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -138,7 +138,7 @@ Last but not least, create one or more connectors:: =20 sudo mkdir /config/vkms/my-vkms/connectors/connector0 =20 -Connectors have 5 configurable attribute: +Connectors have 7 configurable attribute: =20 - status: Connection status: 1 connected, 2 disconnected, 3 unknown (same = values as those exposed by the "status" property of a connector) @@ -150,7 +150,9 @@ Connectors have 5 configurable attribute: - edid_enabled: Enable or not EDID for this connector. Some connectors may= not have an EDID but just a list of modes, this attribute allows to disable EDID pro= perty. - edid: Content of the EDID. Ignored if edid_enabled is not set - +- dynamic: Set to 1 while configuring the device to create a dynamic conne= ctor. A dynamic + connector can be used to emulate DP MST connectors. +- enabled: For dynamic connector, set it to 1 to create the connector, 0 t= o remove it. =20 To finish the configuration, link the different pipeline items:: =20 diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vk= ms_configfs.c index 20f5150e8b24..657381a8a4c2 100644 --- a/drivers/gpu/drm/vkms/vkms_configfs.c +++ b/drivers/gpu/drm/vkms/vkms_configfs.c @@ -1144,6 +1144,12 @@ static ssize_t connector_status_show(struct config_i= tem *item, char *page) return sprintf(page, "%u", status); } =20 +static bool connector_is_enabled(struct vkms_config_connector *connector_c= fg) +{ + return !connector_cfg->dynamic || + (connector_cfg->dynamic && connector_cfg->enabled); +} + static ssize_t connector_status_store(struct config_item *item, const char *page, size_t count) { @@ -1163,7 +1169,7 @@ static ssize_t connector_status_store(struct config_i= tem *item, scoped_guard(mutex, &connector->dev->lock) { vkms_config_connector_set_status(connector->config, status); =20 - if (connector->dev->enabled) + if (connector->dev->enabled && connector_is_enabled(connector->config)) vkms_trigger_connector_hotplug(connector->dev->config->dev); } =20 @@ -1224,7 +1230,7 @@ static ssize_t connector_type_store(struct config_ite= m *item, } =20 scoped_guard(mutex, &connector->dev->lock) { - if (connector->dev->enabled) + if (connector->dev->enabled && connector_is_enabled(connector->config)) return -EBUSY; =20 vkms_config_connector_set_type(connector->config, val); @@ -1343,6 +1349,107 @@ static ssize_t connector_edid_store(struct config_i= tem *item, connector_status_disconnected) vkms_trigger_connector_hotplug(connector->dev->config->dev); } + return count; +} + +static ssize_t connector_enabled_show(struct config_item *item, char *page) +{ + struct vkms_configfs_connector *connector; + bool enabled; + + connector =3D connector_item_to_vkms_configfs_connector(item); + + scoped_guard(mutex, &connector->dev->lock) + enabled =3D vkms_config_connector_is_enabled(connector->config); + + return sprintf(page, "%d\n", enabled); +} + +static ssize_t connector_enabled_store(struct config_item *item, + const char *page, size_t count) +{ + struct vkms_configfs_connector *connector; + struct vkms_config_connector *connector_cfg; + bool enabled, was_enabled; + + connector =3D connector_item_to_vkms_configfs_connector(item); + connector_cfg =3D connector->config; + + if (kstrtobool(page, &enabled)) + return -EINVAL; + scoped_guard(mutex, &connector->dev->lock) { + if (!connector->dev->enabled) { + vkms_config_connector_set_enabled(connector_cfg, enabled); + } else { + // Only dynamic connector can be enabled/disabled at runtime + if (!connector_cfg->dynamic) + return -EBUSY; + + was_enabled =3D vkms_config_connector_is_enabled(connector_cfg); + vkms_config_connector_set_enabled(connector_cfg, enabled); + + // Resulting configuration is invalid (missing encoder for example) + // Early return to avoid drm core issue + if (!vkms_config_is_valid(connector->dev->config)) { + count =3D -EINVAL; + goto rollback; + } + + if (!was_enabled && enabled) { + // Adding the connector + connector_cfg->connector =3D vkms_connector_hot_add(connector->dev->co= nfig->dev, + connector_cfg); + if (IS_ERR(connector_cfg->connector)) { + count =3D PTR_ERR(connector_cfg->connector); + goto rollback; + } + } else if (was_enabled && !enabled) { + vkms_connector_hot_remove(connector->dev->config->dev, + connector_cfg->connector); + } + } + } + return count; + +rollback: + vkms_config_connector_set_enabled(connector_cfg, was_enabled); + return count; +} + +static ssize_t connector_dynamic_show(struct config_item *item, char *page) +{ + struct vkms_configfs_connector *connector; + bool enabled; + + connector =3D connector_item_to_vkms_configfs_connector(item); + + scoped_guard(mutex, &connector->dev->lock) { + enabled =3D vkms_config_connector_is_dynamic(connector->config); + } + + return sprintf(page, "%d\n", enabled); +} + +static ssize_t connector_dynamic_store(struct config_item *item, + const char *page, size_t count) +{ + struct vkms_configfs_connector *connector; + struct vkms_config_connector *connector_cfg; + bool dynamic; + + connector =3D connector_item_to_vkms_configfs_connector(item); + connector_cfg =3D connector->config; + + if (kstrtobool(page, &dynamic)) + return -EINVAL; + + scoped_guard(mutex, &connector->dev->lock) { + // Can't change the dynamic status when the device is activated + if (connector->dev->enabled) + return -EBUSY; + + vkms_config_connector_set_dynamic(connector_cfg, dynamic); + } =20 return count; } @@ -1352,6 +1459,8 @@ CONFIGFS_ATTR(connector_, type); CONFIGFS_ATTR(connector_, supported_colorspaces); CONFIGFS_ATTR(connector_, edid_enabled); CONFIGFS_ATTR(connector_, edid); +CONFIGFS_ATTR(connector_, dynamic); +CONFIGFS_ATTR(connector_, enabled); =20 static struct configfs_attribute *connector_item_attrs[] =3D { &connector_attr_status, @@ -1359,19 +1468,28 @@ static struct configfs_attribute *connector_item_at= trs[] =3D { &connector_attr_supported_colorspaces, &connector_attr_edid_enabled, &connector_attr_edid, + &connector_attr_dynamic, + &connector_attr_enabled, NULL, }; =20 static void connector_release(struct config_item *item) { struct vkms_configfs_connector *connector; + struct vkms_config_connector *connector_cfg; struct mutex *lock; =20 connector =3D connector_item_to_vkms_configfs_connector(item); + connector_cfg =3D connector->config; lock =3D &connector->dev->lock; =20 scoped_guard(mutex, lock) { + if (connector->dev->enabled && connector_cfg->dynamic && connector_cfg->= enabled) + vkms_connector_hot_remove(connector->dev->config->dev, + connector_cfg->connector); + vkms_config_destroy_connector(connector->config); + kfree(connector); } } @@ -1390,6 +1508,7 @@ static int connector_possible_encoders_allow_link(str= uct config_item *src, struct config_item *target) { struct vkms_configfs_connector *connector; + struct vkms_config_connector *connector_cfg; struct vkms_configfs_encoder *encoder; int ret; =20 @@ -1397,16 +1516,26 @@ static int connector_possible_encoders_allow_link(s= truct config_item *src, return -EINVAL; =20 connector =3D connector_possible_encoders_item_to_vkms_configfs_connector= (src); + connector_cfg =3D connector->config; encoder =3D encoder_item_to_vkms_configfs_encoder(target); =20 scoped_guard(mutex, &connector->dev->lock) { - if (connector->dev->enabled) - return -EBUSY; + if (connector->dev->enabled && connector_cfg->enabled) { + if (!connector_cfg->dynamic) + return -EBUSY; + + ret =3D vkms_connector_hot_attach_encoder(connector->dev->config->dev, + connector->config->connector, + encoder->config->encoder); + if (ret) + return ret; + } =20 ret =3D vkms_config_connector_attach_encoder(connector->config, encoder->config); + if (ret) + return ret; } - return ret; } =20 @@ -1445,9 +1574,6 @@ static struct config_group *make_connector_group(stru= ct config_group *group, dev =3D child_group_to_vkms_configfs_device(group); =20 scoped_guard(mutex, &dev->lock) { - if (dev->enabled) - return ERR_PTR(-EBUSY); - connector =3D kzalloc(sizeof(*connector), GFP_KERNEL); if (!connector) return ERR_PTR(-ENOMEM); @@ -1461,9 +1587,11 @@ static struct config_group *make_connector_group(str= uct config_group *group, return ERR_PTR(ret); } =20 + vkms_config_connector_set_dynamic(connector->config, connector->dev->ena= bled); + vkms_config_connector_set_enabled(connector->config, !connector->dev->en= abled); + config_group_init_type_name(&connector->group, name, &connector_item_type); - config_group_init_type_name(&connector->possible_encoders_group, "possible_encoders", &connector_possible_encoders_group_type); --=20 2.51.2