mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 13:46:47 +07:00
6e5aa7efb2
A reset function solves three problems: 1) It allows us to renegotiate features, eg. if we want to upgrade a guest driver without rebooting the guest. 2) It gives us a clean way of shutting down virtqueues: after a reset, we know that the buffers won't be used by the host, and 3) It helps the guest recover from messed-up drivers. So we remove the ->shutdown hook, and the only way we now remove feature bits is via reset. We leave it to the driver to do the reset before it deletes queues: the balloon driver, for example, needs to chat to the host in its remove function. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
110 lines
4.0 KiB
C
110 lines
4.0 KiB
C
#ifndef _LINUX_VIRTIO_CONFIG_H
|
|
#define _LINUX_VIRTIO_CONFIG_H
|
|
/* Virtio devices use a standardized configuration space to define their
|
|
* features and pass configuration information, but each implementation can
|
|
* store and access that space differently. */
|
|
#include <linux/types.h>
|
|
|
|
/* Status byte for guest to report progress, and synchronize features. */
|
|
/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
|
|
#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
|
|
/* We have found a driver for the device. */
|
|
#define VIRTIO_CONFIG_S_DRIVER 2
|
|
/* Driver has used its parts of the config, and is happy */
|
|
#define VIRTIO_CONFIG_S_DRIVER_OK 4
|
|
/* We've given up on this device. */
|
|
#define VIRTIO_CONFIG_S_FAILED 0x80
|
|
|
|
#ifdef __KERNEL__
|
|
struct virtio_device;
|
|
|
|
/**
|
|
* virtio_config_ops - operations for configuring a virtio device
|
|
* @feature: search for a feature in this config
|
|
* vdev: the virtio_device
|
|
* bit: the feature bit
|
|
* Returns true if the feature is supported. Acknowledges the feature
|
|
* so the host can see it.
|
|
* @get: read the value of a configuration field
|
|
* vdev: the virtio_device
|
|
* offset: the offset of the configuration field
|
|
* buf: the buffer to write the field value into.
|
|
* len: the length of the buffer
|
|
* Note that contents are conventionally little-endian.
|
|
* @set: write the value of a configuration field
|
|
* vdev: the virtio_device
|
|
* offset: the offset of the configuration field
|
|
* buf: the buffer to read the field value from.
|
|
* len: the length of the buffer
|
|
* Note that contents are conventionally little-endian.
|
|
* @get_status: read the status byte
|
|
* vdev: the virtio_device
|
|
* Returns the status byte
|
|
* @set_status: write the status byte
|
|
* vdev: the virtio_device
|
|
* status: the new status byte
|
|
* @reset: reset the device
|
|
* vdev: the virtio device
|
|
* After this, status and feature negotiation must be done again
|
|
* @find_vq: find a virtqueue and instantiate it.
|
|
* vdev: the virtio_device
|
|
* index: the 0-based virtqueue number in case there's more than one.
|
|
* callback: the virqtueue callback
|
|
* Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
|
|
* @del_vq: free a virtqueue found by find_vq().
|
|
*/
|
|
struct virtio_config_ops
|
|
{
|
|
bool (*feature)(struct virtio_device *vdev, unsigned bit);
|
|
void (*get)(struct virtio_device *vdev, unsigned offset,
|
|
void *buf, unsigned len);
|
|
void (*set)(struct virtio_device *vdev, unsigned offset,
|
|
const void *buf, unsigned len);
|
|
u8 (*get_status)(struct virtio_device *vdev);
|
|
void (*set_status)(struct virtio_device *vdev, u8 status);
|
|
void (*reset)(struct virtio_device *vdev);
|
|
struct virtqueue *(*find_vq)(struct virtio_device *vdev,
|
|
unsigned index,
|
|
void (*callback)(struct virtqueue *));
|
|
void (*del_vq)(struct virtqueue *vq);
|
|
};
|
|
|
|
/**
|
|
* virtio_config_val - look for a feature and get a single virtio config.
|
|
* @vdev: the virtio device
|
|
* @fbit: the feature bit
|
|
* @offset: the type to search for.
|
|
* @val: a pointer to the value to fill in.
|
|
*
|
|
* The return value is -ENOENT if the feature doesn't exist. Otherwise
|
|
* the value is endian-corrected and returned in v. */
|
|
#define virtio_config_val(vdev, fbit, offset, v) ({ \
|
|
int _err; \
|
|
if ((vdev)->config->feature((vdev), (fbit))) { \
|
|
__virtio_config_val((vdev), (offset), (v)); \
|
|
_err = 0; \
|
|
} else \
|
|
_err = -ENOENT; \
|
|
_err; \
|
|
})
|
|
|
|
/**
|
|
* __virtio_config_val - get a single virtio config without feature check.
|
|
* @vdev: the virtio device
|
|
* @offset: the type to search for.
|
|
* @val: a pointer to the value to fill in.
|
|
*
|
|
* The value is endian-corrected and returned in v. */
|
|
#define __virtio_config_val(vdev, offset, v) do { \
|
|
BUILD_BUG_ON(sizeof(*(v)) != 1 && sizeof(*(v)) != 2 \
|
|
&& sizeof(*(v)) != 4 && sizeof(*(v)) != 8); \
|
|
(vdev)->config->get((vdev), (offset), (v), sizeof(*(v))); \
|
|
switch (sizeof(*(v))) { \
|
|
case 2: le16_to_cpus((__u16 *) v); break; \
|
|
case 4: le32_to_cpus((__u32 *) v); break; \
|
|
case 8: le64_to_cpus((__u64 *) v); break; \
|
|
} \
|
|
} while(0)
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _LINUX_VIRTIO_CONFIG_H */
|