From nobody Mon Feb 9 09:22:36 2026 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (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 7FC0F354AEC; Wed, 29 Oct 2025 13:31:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761744684; cv=none; b=Bian9L3gNQEihNnWEQBbq/GNM+qxlj9drGcp9WEQ78OZxcyqvznRW6zHkxLF7/LlJCPPRDGxlO4ZBIIlYcIYelHwXfncCF7Joq9iOyrfCeeM/8EeGp3hMqGjDKGeBWHBx3nms201XZ6aZil6w9fUxKBLfSVKbnPoVYtoesOgY+Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761744684; c=relaxed/simple; bh=0c54fSmOm2l+K0LbPt9pg/s8Cgsdy0XFWVvsXyQZpVs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kVlFfeN1e2KY9aTeo9SLlpGHDLu7nWR5nlZVomVQAQ6fTVhjC0dQruimRPdKGPI4TeLNF/axDdNDrnUgIJcG1fni1JvnSJtXZ60/7B2B4sk8Bh8/RfcfRer6fVo2vZKJFxNd3FhwxexFcYeCSkgGMZxyEpc4tucGcyVQpdQ/O2g= 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=gsXeB90T; arc=none smtp.client-ip=185.171.202.116 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="gsXeB90T" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id B89D8C0DB01; Wed, 29 Oct 2025 13:30:59 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 1C933606E8; Wed, 29 Oct 2025 13:31:20 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id DE770117F809E; Wed, 29 Oct 2025 14:31:17 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1761744679; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=SpkB+O9TsCu/AbXZ5AMtN1pcUFMsRO/D92Oon6XNGNc=; b=gsXeB90TW4MFEkUcr/Q9xeBIcxsOm+Rb92bzdWDsde2Z9bqy18mdT5zYXe/d17Vvt2QHGV cYVghI/e3lKi2tcQjP+WdB+QditORMGMiu/RGlqJsCjzNl/sF/VnO1UgM53ZkKobk80ImV VL0o6eQgMk94YyslJct1M2t8hGRAgbszI3pOJWlYW9TWgy6Jla/NhFQZSMrh0FnpVFuYC3 43d8VUubtH7cgG0P2MXxNsGZzkevWPGT+oMe/2i7CXeuLlNPeIX/og1D16QMW1zpSKMBMS rf0PZfbXj4bHwzhn5vHnFSfeLkqY98h/EyIx7VWou94nM53LaWnSu7vjICVZtw== From: Louis Chauvet Date: Wed, 29 Oct 2025 14:30:42 +0100 Subject: [PATCH v2 32/32] 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: <20251029-vkms-all-config-v2-32-be20b9bf146e@bootlin.com> References: <20251029-vkms-all-config-v2-0-be20b9bf146e@bootlin.com> In-Reply-To: <20251029-vkms-all-config-v2-0-be20b9bf146e@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=10022; i=louis.chauvet@bootlin.com; h=from:subject:message-id; bh=0c54fSmOm2l+K0LbPt9pg/s8Cgsdy0XFWVvsXyQZpVs=; b=owEBbQKS/ZANAwAKASCtLsZbECziAcsmYgBpAhbs7JkS7/65uQ2RhYBbB92eyBeYurpxDw6xx r+IRE8dy+iJAjMEAAEKAB0WIQRPj7g/vng8MQxQWQQgrS7GWxAs4gUCaQIW7AAKCRAgrS7GWxAs 4gQfEACqyG2bsUnE+q6UxmOYg/EqOEyZVzhMZPnEweXrZ9y2YnXB+eZLHW39kN1m16RRT+C0aR9 eQD2FO5UsP3a7yGChzYnN5OF3qqFdAhky8DWrbGZoLcNOaUR6S/xW+XrbLTAftAaAmrVy77dna0 mmoJXX2ug6+QvujkgiGVDYenDqvfae/g+zaCCGuhWqiqaWwNuaUfl+ADM0hm4lD+ZjeXqb5e14p bGFjI+TW1lOKUKmli1En3Ongzz3HVhOftLAe4Wzeo6+Lth7wf1pFBAtoFgfGgjwMF1JTotAcZJj pwOucLBMtuqqw/mUhXvIVHryBI89Ce8xW6JQ3vou1HpkMBq2nCnvLCptGYo8MOGksB4ri0Ontf2 h6TnpP2KYM+Iymoz6zdz3XkPniJivfxLbVf+sgGXQFa5mwe5EdTc0KSt/jDO8vxD0kC809DSvUF X77kfbM551CakdXTmPtRNf05HUJUDFOPHd4JJdvekf7EUBxMJ46YBUA/T0h6W403HOM2S7qVkno HwSbR0Gyz0IVM39NPIG7OirJWMqPIJPRGP4zABchgl6zgtkL02sW7eVaIVaxkL+I6grE57/tjH0 ZuhjA9dvjsaT4iTqJL4jAjIQ2uhdjbNri1QOzpdoFSVFT1QAVTlSQkDFxpr8Yx9JEqDjK2llGBe Hpr6AZC2Dvub6Tw== 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/gpu/vkms.rst | 6 +- drivers/gpu/drm/vkms/vkms_configfs.c | 153 +++++++++++++++++++++++++++++++= +--- 2 files changed, 146 insertions(+), 13 deletions(-) diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 0cc7897d7b83..afed12132ae7 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 1843e5d9e1e1..b4315c6cb25c 100644 --- a/drivers/gpu/drm/vkms/vkms_configfs.c +++ b/drivers/gpu/drm/vkms/vkms_configfs.c @@ -1135,6 +1135,12 @@ 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) { @@ -1154,8 +1160,10 @@ static ssize_t connector_status_store(struct config_= item *item, scoped_guard(mutex, &connector->dev->lock) { vkms_config_connector_set_status(connector->config, status); =20 - if (connector->dev->enabled) - vkms_trigger_connector_hotplug(connector->dev->config->dev); + if (connector->dev->enabled) { + if (connector_is_enabled(connector->config)) + vkms_trigger_connector_hotplug(connector->dev->config->dev); + } } =20 return (ssize_t)count; @@ -1215,8 +1223,10 @@ static ssize_t connector_type_store(struct config_it= em *item, } =20 scoped_guard(mutex, &connector->dev->lock) { - if (connector->dev->enabled) - return -EINVAL; + if (connector->dev->enabled) { + if (connector_is_enabled(connector->config)) + return -EBUSY; + } vkms_config_connector_set_type(connector->config, val); } =20 @@ -1332,6 +1342,107 @@ 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; } @@ -1341,6 +1452,8 @@ 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, @@ -1348,19 +1461,28 @@ 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); } } @@ -1379,6 +1501,7 @@ 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 @@ -1386,16 +1509,25 @@ 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 @@ -1433,9 +1565,6 @@ 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); @@ -1448,9 +1577,11 @@ static struct config_group *make_connector_group(str= uct config_group *group, return ERR_CAST(connector->config); } =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 2.51.0