From 224de6f886f8184fd448700a6d78f216694de948 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 14 Aug 2024 13:22:26 +0800 Subject: virtio: allow driver to disable the configure change notification Sometime, it would be useful to disable the configure change notification from the driver. So this patch allows this by introducing a variable config_change_driver_disabled and only allow the configure change notification callback to be triggered when it is allowed by both the virtio core and the driver. It is set to false by default to hold the current semantic so we don't need to change any drivers. The first user for this would be virtio-net. Cc: Venkat Venkatsubra Cc: Gia-Khanh Nguyen Acked-by: Michael S. Tsirkin Signed-off-by: Jason Wang Link: https://patch.msgid.link/20240814052228.4654-3-jasowang@redhat.com Signed-off-by: Jakub Kicinski --- drivers/virtio/virtio.c | 39 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 6b692b0fa578..b9095751e43b 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -127,10 +127,12 @@ static void __virtio_config_changed(struct virtio_device *dev) { struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); - if (!dev->config_core_enabled) + if (!dev->config_core_enabled || dev->config_driver_disabled) dev->config_change_pending = true; - else if (drv && drv->config_changed) + else if (drv && drv->config_changed) { drv->config_changed(dev); + dev->config_change_pending = false; + } } void virtio_config_changed(struct virtio_device *dev) @@ -143,6 +145,38 @@ void virtio_config_changed(struct virtio_device *dev) } EXPORT_SYMBOL_GPL(virtio_config_changed); +/** + * virtio_config_driver_disable - disable config change reporting by drivers + * @dev: the device to reset + * + * This is only allowed to be called by a driver and disabling can't + * be nested. + */ +void virtio_config_driver_disable(struct virtio_device *dev) +{ + spin_lock_irq(&dev->config_lock); + dev->config_driver_disabled = true; + spin_unlock_irq(&dev->config_lock); +} +EXPORT_SYMBOL_GPL(virtio_config_driver_disable); + +/** + * virtio_config_driver_enable - enable config change reporting by drivers + * @dev: the device to reset + * + * This is only allowed to be called by a driver and enabling can't + * be nested. + */ +void virtio_config_driver_enable(struct virtio_device *dev) +{ + spin_lock_irq(&dev->config_lock); + dev->config_driver_disabled = false; + if (dev->config_change_pending) + __virtio_config_changed(dev); + spin_unlock_irq(&dev->config_lock); +} +EXPORT_SYMBOL_GPL(virtio_config_driver_enable); + static void virtio_config_core_disable(struct virtio_device *dev) { spin_lock_irq(&dev->config_lock); @@ -156,7 +190,6 @@ static void virtio_config_core_enable(struct virtio_device *dev) dev->config_core_enabled = true; if (dev->config_change_pending) __virtio_config_changed(dev); - dev->config_change_pending = false; spin_unlock_irq(&dev->config_lock); } -- cgit v1.2.3