On Mon, 27 Oct 2025 12:39:48 -0500, Daniel Jurgens <[email protected]> wrote: > Currently querying and setting capabilities is restricted to a single > capability and contained within the virtio PCI driver. However, each > device type has generic and device specific capabilities, that may be > queried and set. In subsequent patches virtio_net will query and set > flow filter capabilities. > > Signed-off-by: Daniel Jurgens <[email protected]> > Reviewed-by: Parav Pandit <[email protected]>
Reviewed-by: Xuan Zhuo <[email protected]> > > --- > v4: Moved this logic from virtio_pci_modern to new file > virtio_admin_commands. > --- > drivers/virtio/Makefile | 2 +- > drivers/virtio/virtio_admin_commands.c | 90 ++++++++++++++++++++++++++ > include/linux/virtio_admin.h | 80 +++++++++++++++++++++++ > include/uapi/linux/virtio_pci.h | 7 +- > 4 files changed, 176 insertions(+), 3 deletions(-) > create mode 100644 drivers/virtio/virtio_admin_commands.c > create mode 100644 include/linux/virtio_admin.h > > diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile > index eefcfe90d6b8..2b4a204dde33 100644 > --- a/drivers/virtio/Makefile > +++ b/drivers/virtio/Makefile > @@ -1,5 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0 > -obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o > +obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o virtio_admin_commands.o > obj-$(CONFIG_VIRTIO_ANCHOR) += virtio_anchor.o > obj-$(CONFIG_VIRTIO_PCI_LIB) += virtio_pci_modern_dev.o > obj-$(CONFIG_VIRTIO_PCI_LIB_LEGACY) += virtio_pci_legacy_dev.o > diff --git a/drivers/virtio/virtio_admin_commands.c > b/drivers/virtio/virtio_admin_commands.c > new file mode 100644 > index 000000000000..94751d16b3c4 > --- /dev/null > +++ b/drivers/virtio/virtio_admin_commands.c > @@ -0,0 +1,90 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include <linux/virtio.h> > +#include <linux/virtio_config.h> > +#include <linux/virtio_admin.h> > + > +int virtio_admin_cap_id_list_query(struct virtio_device *vdev, > + struct virtio_admin_cmd_query_cap_id_result > *data) > +{ > + struct virtio_admin_cmd cmd = {}; > + struct scatterlist result_sg; > + > + if (!vdev->config->admin_cmd_exec) > + return -EOPNOTSUPP; > + > + sg_init_one(&result_sg, data, sizeof(*data)); > + cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_CAP_ID_LIST_QUERY); > + cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SELF); > + cmd.result_sg = &result_sg; > + > + return vdev->config->admin_cmd_exec(vdev, &cmd); > +} > +EXPORT_SYMBOL_GPL(virtio_admin_cap_id_list_query); > + > +int virtio_admin_cap_get(struct virtio_device *vdev, > + u16 id, > + void *caps, > + size_t cap_size) > +{ > + struct virtio_admin_cmd_cap_get_data *data; > + struct virtio_admin_cmd cmd = {}; > + struct scatterlist result_sg; > + struct scatterlist data_sg; > + int err; > + > + if (!vdev->config->admin_cmd_exec) > + return -EOPNOTSUPP; > + > + data = kzalloc(sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->id = cpu_to_le16(id); > + sg_init_one(&data_sg, data, sizeof(*data)); > + sg_init_one(&result_sg, caps, cap_size); > + cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_DEVICE_CAP_GET); > + cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SELF); > + cmd.data_sg = &data_sg; > + cmd.result_sg = &result_sg; > + > + err = vdev->config->admin_cmd_exec(vdev, &cmd); > + kfree(data); > + > + return err; > +} > +EXPORT_SYMBOL_GPL(virtio_admin_cap_get); > + > +int virtio_admin_cap_set(struct virtio_device *vdev, > + u16 id, > + const void *caps, > + size_t cap_size) > +{ > + struct virtio_admin_cmd_cap_set_data *data; > + struct virtio_admin_cmd cmd = {}; > + struct scatterlist data_sg; > + size_t data_size; > + int err; > + > + if (!vdev->config->admin_cmd_exec) > + return -EOPNOTSUPP; > + > + data_size = sizeof(*data) + cap_size; > + data = kzalloc(data_size, GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->id = cpu_to_le16(id); > + memcpy(data->cap_specific_data, caps, cap_size); > + sg_init_one(&data_sg, data, data_size); > + cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_DRIVER_CAP_SET); > + cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SELF); > + cmd.data_sg = &data_sg; > + cmd.result_sg = NULL; > + > + err = vdev->config->admin_cmd_exec(vdev, &cmd); > + kfree(data); > + > + return err; > +} > +EXPORT_SYMBOL_GPL(virtio_admin_cap_set); > diff --git a/include/linux/virtio_admin.h b/include/linux/virtio_admin.h > new file mode 100644 > index 000000000000..36df97b6487a > --- /dev/null > +++ b/include/linux/virtio_admin.h > @@ -0,0 +1,80 @@ > +/* SPDX-License-Identifier: GPL-2.0-only > + * > + * Header file for virtio admin operations > + */ > +#include <uapi/linux/virtio_pci.h> > + > +#ifndef _LINUX_VIRTIO_ADMIN_H > +#define _LINUX_VIRTIO_ADMIN_H > + > +struct virtio_device; > + > +/** > + * VIRTIO_CAP_IN_LIST - Check if a capability is supported in the capability > list > + * @cap_list: Pointer to capability list structure containing supported_caps > array > + * @cap: Capability ID to check > + * > + * The cap_list contains a supported_caps array of little-endian 64-bit > integers > + * where each bit represents a capability. Bit 0 of the first element > represents > + * capability ID 0, bit 1 represents capability ID 1, and so on. > + * > + * Return: 1 if capability is supported, 0 otherwise > + */ > +#define VIRTIO_CAP_IN_LIST(cap_list, cap) \ > + (!!(1 & (le64_to_cpu(cap_list->supported_caps[cap / 64]) >> cap % 64))) > + > +/** > + * virtio_admin_cap_id_list_query - Query the list of available capability > IDs > + * @vdev: The virtio device to query > + * @data: Pointer to result structure (must be heap allocated) > + * > + * This function queries the virtio device for the list of available > capability > + * IDs that can be used with virtio_admin_cap_get() and > virtio_admin_cap_set(). > + * The result is stored in the provided data structure. > + * > + * Return: 0 on success, -EOPNOTSUPP if the device doesn't support admin > + * operations or capability queries, or a negative error code on other > failures. > + */ > +int virtio_admin_cap_id_list_query(struct virtio_device *vdev, > + struct virtio_admin_cmd_query_cap_id_result > *data); > + > +/** > + * virtio_admin_cap_get - Get capability data for a specific capability ID > + * @vdev: The virtio device > + * @id: Capability ID to retrieve > + * @caps: Pointer to capability data structure (must be heap allocated) > + * @cap_size: Size of the capability data structure > + * > + * This function retrieves a specific capability from the virtio device. > + * The capability data is stored in the provided buffer. The caller must > + * ensure the buffer is large enough to hold the capability data. > + * > + * Return: 0 on success, -EOPNOTSUPP if the device doesn't support admin > + * operations or capability retrieval, or a negative error code on other > failures. > + */ > +int virtio_admin_cap_get(struct virtio_device *vdev, > + u16 id, > + void *caps, > + size_t cap_size); > + > +/** > + * virtio_admin_cap_set - Set capability data for a specific capability ID > + * @vdev: The virtio device > + * @id: Capability ID to set > + * @caps: Pointer to capability data structure (must be heap allocated) > + * @cap_size: Size of the capability data structure > + * > + * This function sets a specific capability on the virtio device. > + * The capability data is read from the provided buffer and applied > + * to the device. The device may validate the capability data before > + * applying it. > + * > + * Return: 0 on success, -EOPNOTSUPP if the device doesn't support admin > + * operations or capability setting, or a negative error code on other > failures. > + */ > +int virtio_admin_cap_set(struct virtio_device *vdev, > + u16 id, > + const void *caps, > + size_t cap_size); > + > +#endif /* _LINUX_VIRTIO_ADMIN_H */ > diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h > index c691ac210ce2..0d5ca0cff629 100644 > --- a/include/uapi/linux/virtio_pci.h > +++ b/include/uapi/linux/virtio_pci.h > @@ -315,15 +315,18 @@ struct virtio_admin_cmd_notify_info_result { > > #define VIRTIO_DEV_PARTS_CAP 0x0000 > > +/* Update this value to largest implemented cap number. */ > +#define VIRTIO_ADMIN_MAX_CAP 0x0fff > + > struct virtio_dev_parts_cap { > __u8 get_parts_resource_objects_limit; > __u8 set_parts_resource_objects_limit; > }; > > -#define MAX_CAP_ID __KERNEL_DIV_ROUND_UP(VIRTIO_DEV_PARTS_CAP + 1, 64) > +#define VIRTIO_ADMIN_CAP_ID_ARRAY_SIZE > __KERNEL_DIV_ROUND_UP(VIRTIO_ADMIN_MAX_CAP, 64) > > struct virtio_admin_cmd_query_cap_id_result { > - __le64 supported_caps[MAX_CAP_ID]; > + __le64 supported_caps[VIRTIO_ADMIN_CAP_ID_ARRAY_SIZE]; > }; > > struct virtio_admin_cmd_cap_get_data { > -- > 2.50.1 >
