diff options
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/virtio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 8 | ||||
| -rw-r--r-- | drivers/virtio/virtio_debug.c | 114 | ||||
| -rw-r--r-- | drivers/virtio/virtio_mem.c | 1 | ||||
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 7 |
6 files changed, 135 insertions, 6 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index c17193544268..6284538a8184 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -178,4 +178,14 @@ config VIRTIO_DMA_SHARED_BUFFER This option adds a flavor of dma buffers that are backed by virtio resources. +config VIRTIO_DEBUG + bool "Debug facilities" + depends on VIRTIO + help + Enable this to expose debug facilities over debugfs. + This allows to debug features, to see what features the device + advertises and to set filter for features used by driver. + + If unsure, say N. + endif # VIRTIO_MENU diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 73ace62af440..58b2b0489fc9 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o obj-$(CONFIG_VIRTIO_VDPA) += virtio_vdpa.o obj-$(CONFIG_VIRTIO_MEM) += virtio_mem.o obj-$(CONFIG_VIRTIO_DMA_SHARED_BUFFER) += virtio_dma_buf.o +obj-$(CONFIG_VIRTIO_DEBUG) += virtio_debug.o diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 9510c551dce8..b968b2aa5f4d 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -274,6 +274,9 @@ static int virtio_dev_probe(struct device *_d) else dev->features = driver_features_legacy & device_features; + /* When debugging, user may filter some features by hand. */ + virtio_debug_device_filter_features(dev); + /* Transport features always preserved to pass to finalize_features. */ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) if (device_features & (1ULL << i)) @@ -465,6 +468,8 @@ int register_virtio_device(struct virtio_device *dev) /* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); + virtio_debug_device_init(dev); + /* * device_add() causes the bus infrastructure to look for a matching * driver. @@ -496,6 +501,7 @@ void unregister_virtio_device(struct virtio_device *dev) int index = dev->index; /* save for after device release */ device_unregister(&dev->dev); + virtio_debug_device_exit(dev); ida_free(&virtio_index_ida, index); } EXPORT_SYMBOL_GPL(unregister_virtio_device); @@ -590,11 +596,13 @@ static int virtio_init(void) { if (bus_register(&virtio_bus) != 0) panic("virtio bus registration failed"); + virtio_debug_init(); return 0; } static void __exit virtio_exit(void) { + virtio_debug_exit(); bus_unregister(&virtio_bus); ida_destroy(&virtio_index_ida); } diff --git a/drivers/virtio/virtio_debug.c b/drivers/virtio/virtio_debug.c new file mode 100644 index 000000000000..95c8fc7705bb --- /dev/null +++ b/drivers/virtio/virtio_debug.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/debugfs.h> + +static struct dentry *virtio_debugfs_dir; + +static int virtio_debug_device_features_show(struct seq_file *s, void *data) +{ + struct virtio_device *dev = s->private; + u64 device_features; + unsigned int i; + + device_features = dev->config->get_features(dev); + for (i = 0; i < BITS_PER_LONG_LONG; i++) { + if (device_features & (1ULL << i)) + seq_printf(s, "%u\n", i); + } + return 0; +} +DEFINE_SHOW_ATTRIBUTE(virtio_debug_device_features); + +static int virtio_debug_filter_features_show(struct seq_file *s, void *data) +{ + struct virtio_device *dev = s->private; + unsigned int i; + + for (i = 0; i < BITS_PER_LONG_LONG; i++) { + if (dev->debugfs_filter_features & (1ULL << i)) + seq_printf(s, "%u\n", i); + } + return 0; +} +DEFINE_SHOW_ATTRIBUTE(virtio_debug_filter_features); + +static int virtio_debug_filter_features_clear(void *data, u64 val) +{ + struct virtio_device *dev = data; + + if (val == 1) + dev->debugfs_filter_features = 0; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_features_clear_fops, NULL, + virtio_debug_filter_features_clear, "%llu\n"); + +static int virtio_debug_filter_feature_add(void *data, u64 val) +{ + struct virtio_device *dev = data; + + if (val >= BITS_PER_LONG_LONG) + return -EINVAL; + dev->debugfs_filter_features |= BIT_ULL_MASK(val); + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_add_fops, NULL, + virtio_debug_filter_feature_add, "%llu\n"); + +static int virtio_debug_filter_feature_del(void *data, u64 val) +{ + struct virtio_device *dev = data; + + if (val >= BITS_PER_LONG_LONG) + return -EINVAL; + dev->debugfs_filter_features &= ~BIT_ULL_MASK(val); + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(virtio_debug_filter_feature_del_fops, NULL, + virtio_debug_filter_feature_del, "%llu\n"); + +void virtio_debug_device_init(struct virtio_device *dev) +{ + dev->debugfs_dir = debugfs_create_dir(dev_name(&dev->dev), + virtio_debugfs_dir); + debugfs_create_file("device_features", 0400, dev->debugfs_dir, dev, + &virtio_debug_device_features_fops); + debugfs_create_file("filter_features", 0400, dev->debugfs_dir, dev, + &virtio_debug_filter_features_fops); + debugfs_create_file("filter_features_clear", 0200, dev->debugfs_dir, dev, + &virtio_debug_filter_features_clear_fops); + debugfs_create_file("filter_feature_add", 0200, dev->debugfs_dir, dev, + &virtio_debug_filter_feature_add_fops); + debugfs_create_file("filter_feature_del", 0200, dev->debugfs_dir, dev, + &virtio_debug_filter_feature_del_fops); +} +EXPORT_SYMBOL_GPL(virtio_debug_device_init); + +void virtio_debug_device_filter_features(struct virtio_device *dev) +{ + dev->features &= ~dev->debugfs_filter_features; +} +EXPORT_SYMBOL_GPL(virtio_debug_device_filter_features); + +void virtio_debug_device_exit(struct virtio_device *dev) +{ + debugfs_remove_recursive(dev->debugfs_dir); +} +EXPORT_SYMBOL_GPL(virtio_debug_device_exit); + +void virtio_debug_init(void) +{ + virtio_debugfs_dir = debugfs_create_dir("virtio", NULL); +} +EXPORT_SYMBOL_GPL(virtio_debug_init); + +void virtio_debug_exit(void) +{ + debugfs_remove_recursive(virtio_debugfs_dir); +} +EXPORT_SYMBOL_GPL(virtio_debug_exit); diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 6d4dfbc53a66..a3857bacc844 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -21,6 +21,7 @@ #include <linux/bitmap.h> #include <linux/lockdep.h> #include <linux/log2.h> +#include <linux/vmalloc.h> #include <linux/suspend.h> #include <acpi/acpi_numa.h> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 6f7e5010a673..2a972752ff1b 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2782,7 +2782,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize); * * Returns zero or a negative error. * 0: success. - * -EINVAL: vring does not use the dma api, so we can not enable premapped mode. + * -EINVAL: too late to enable premapped mode, the vq already contains buffers. */ int virtqueue_set_dma_premapped(struct virtqueue *_vq) { @@ -2798,11 +2798,6 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq) return -EINVAL; } - if (!vq->use_dma_api) { - END_USE(vq); - return -EINVAL; - } - vq->premapped = true; vq->do_unmap = false; |