From mboxrd@z Thu Jan 1 00:00:00 1970 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 E4A953ED121 for ; Wed, 22 Apr 2026 16:50:29 +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=1776876631; cv=none; b=u72ow1V0RPv0gsBK/lq6EcgiKlNJbN6L2RBDWLpFY/MEInVsOIQK7bgDSwPZcGHVy00VfkUsKKezk8F6sNx23fJ9+whwZkaGzSHLjmv6t4Lxqyqy1NnAtjixU1H0CIIseRrg05QnKS7YWMfyNJFmyJ4OHS88hGKUIrLVGZJP7eI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776876631; c=relaxed/simple; bh=MhgQZVo5mM+SbMlw3Zh+zIZAyeIMY0fOeD1mJjTbQdk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=NPAVIfmLzd9FUWE65BONRFxsi6fsm+odDwEwzudLKPZjddasBSYZ0BO1Y5OApFbImQMCPZF5EVr81xDapb6LMji1guW8xos10SHoI4LUdK4pdeyR2Fe0FX+IFG2GjcSoB66qONstsbn01/jUmMU+e6DpuyhVRPkDuEbtOW5m+MM= 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=qeG4FwfX; 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="qeG4FwfX" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 7B3241A33B1; Wed, 22 Apr 2026 16:50:28 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 4F6FA5FA8F; Wed, 22 Apr 2026 16:50:28 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 32FCF104609C6; Wed, 22 Apr 2026 18:50:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1776876626; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=YWYQQ4DJG3y5givOnEvKOstRYLRy/YajII17uK3gjZA=; b=qeG4FwfXodwnpLG2EtM8miNOf6msFIFxNXn8Ct8SvO3RpBPJtKHv9TOKYW8wit9v3pOjFm uPkfHVbm+T2OLitxfY2d3/EbiNmOgRwdc+x2hcKUJX8zNDLaJ6whF3kcs9NmmQZYxmSywI sJkkwKZ7BOe2IZz578kUlURUt9VAk0qKRJ/oHGd3EJ0yOysTglouzLEguunU/fhfLNrtyn iSqWDyOC2EDiHrn827z4iKfNj1U1OCpbDnPZlO2BVFvKrAGzy1fEQQhEGtD8F9jwkZV1Ep mrkG3AU8/T0LWk0KG0FrWlNTrkbMSbkBm4yUbLHah5mHwg5IdFyBI2hgKtscUw== From: Louis Chauvet Date: Wed, 22 Apr 2026 18:48:32 +0200 Subject: [PATCH v4 35/37] drm/vkms: Introduce configfs for dynamic connector creation Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260422-vkms-all-config-v4-35-dbb52e9aadc3@bootlin.com> References: <20260422-vkms-all-config-v4-0-dbb52e9aadc3@bootlin.com> In-Reply-To: <20260422-vkms-all-config-v4-0-dbb52e9aadc3@bootlin.com> To: Haneen Mohammed , Simona Vetter , Melissa Wen , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , jose.exposito89@gmail.com, Jonathan Corbet , Shuah Khan , Miguel Ojeda , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt 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 , llvm@lists.linux.dev X-Mailer: b4 0.16-dev 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: José Expósito Signed-off-by: José Expósito Signed-off-by: Louis Chauvet --- Documentation/ABI/testing/configfs-vkms | 14 ++++ Documentation/gpu/vkms.rst | 6 +- drivers/gpu/drm/vkms/vkms_configfs.c | 144 ++++++++++++++++++++++++++++++-- 3 files changed, 155 insertions(+), 9 deletions(-) diff --git a/Documentation/ABI/testing/configfs-vkms b/Documentation/ABI/testing/configfs-vkms index 8215cd3ff466..99911aa36467 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. +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_encoders Date: Nov 2025 Contact: dri-devel@lists.freedesktop.org diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index a7d6a4a3b53b..5c013014c457 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -138,7 +138,7 @@ Last but not least, create one or more connectors:: sudo mkdir /config/vkms/my-vkms/connectors/connector0 -Connectors have 5 configurable attribute: +Connectors have 7 configurable attribute: - 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 property. - edid: Content of the EDID. Ignored if edid_enabled is not set - +- dynamic: Set to 1 while configuring the device to create a dynamic connector. A dynamic + connector can be used to emulate DP MST connectors. +- enabled: For dynamic connector, set it to 1 to create the connector, 0 to remove it. To finish the configuration, link the different pipeline items:: diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c index cf388851910b..e7752ac1cd51 100644 --- a/drivers/gpu/drm/vkms/vkms_configfs.c +++ b/drivers/gpu/drm/vkms/vkms_configfs.c @@ -1147,6 +1147,12 @@ static ssize_t connector_status_show(struct config_item *item, char *page) return sprintf(page, "%u", status); } +static bool connector_is_enabled(struct vkms_config_connector *connector_cfg) +{ + 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) { @@ -1166,7 +1172,7 @@ static ssize_t connector_status_store(struct config_item *item, scoped_guard(mutex, &connector->dev->lock) { vkms_config_connector_set_status(connector->config, status); - if (connector->dev->enabled) + if (connector->dev->enabled && connector_is_enabled(connector->config)) vkms_trigger_connector_hotplug(connector->dev->config->dev); } @@ -1227,7 +1233,7 @@ static ssize_t connector_type_store(struct config_item *item, } scoped_guard(mutex, &connector->dev->lock) { - if (connector->dev->enabled) + if (connector->dev->enabled && connector_is_enabled(connector->config)) return -EBUSY; vkms_config_connector_set_type(connector->config, val); @@ -1346,6 +1352,107 @@ static ssize_t connector_edid_store(struct config_item *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 = connector_item_to_vkms_configfs_connector(item); + + scoped_guard(mutex, &connector->dev->lock) + enabled = 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 = connector_item_to_vkms_configfs_connector(item); + connector_cfg = 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 = 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 = -EINVAL; + goto rollback; + } + + if (!was_enabled && enabled) { + // Adding the connector + connector_cfg->connector = vkms_connector_hot_add(connector->dev->config->dev, + connector_cfg); + if (IS_ERR(connector_cfg->connector)) { + count = 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 = connector_item_to_vkms_configfs_connector(item); + + scoped_guard(mutex, &connector->dev->lock) { + enabled = 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 = connector_item_to_vkms_configfs_connector(item); + connector_cfg = 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); + } return count; } @@ -1355,6 +1462,8 @@ 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); static struct configfs_attribute *connector_item_attrs[] = { &connector_attr_status, @@ -1362,19 +1471,28 @@ static struct configfs_attribute *connector_item_attrs[] = { &connector_attr_supported_colorspaces, &connector_attr_edid_enabled, &connector_attr_edid, + &connector_attr_dynamic, + &connector_attr_enabled, NULL, }; static void connector_release(struct config_item *item) { struct vkms_configfs_connector *connector; + struct vkms_config_connector *connector_cfg; struct mutex *lock; connector = connector_item_to_vkms_configfs_connector(item); + connector_cfg = connector->config; lock = &connector->dev->lock; 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); } } @@ -1393,6 +1511,7 @@ static int connector_possible_encoders_allow_link(struct 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; @@ -1400,14 +1519,25 @@ static int connector_possible_encoders_allow_link(struct config_item *src, return -EINVAL; connector = connector_possible_encoders_item_to_vkms_configfs_connector(src); + connector_cfg = connector->config; encoder = encoder_item_to_vkms_configfs_encoder(target); 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 = vkms_connector_hot_attach_encoder(connector->dev->config->dev, + connector->config->connector, + encoder->config->encoder); + if (ret) + return ret; + } ret = vkms_config_connector_attach_encoder(connector->config, encoder->config); + if (ret) + return ret; } return ret; @@ -1448,9 +1578,6 @@ static struct config_group *make_connector_group(struct config_group *group, dev = child_group_to_vkms_configfs_device(group); scoped_guard(mutex, &dev->lock) { - if (dev->enabled) - return ERR_PTR(-EBUSY); - connector = kzalloc(sizeof(*connector), GFP_KERNEL); if (!connector) return ERR_PTR(-ENOMEM); @@ -1464,6 +1591,9 @@ static struct config_group *make_connector_group(struct config_group *group, return ERR_PTR(ret); } + vkms_config_connector_set_dynamic(connector->config, connector->dev->enabled); + vkms_config_connector_set_enabled(connector->config, !connector->dev->enabled); + config_group_init_type_name(&connector->group, name, &connector_item_type); -- 2.54.0