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qemu-e2k/hw/virtio.h
Michael S. Tsirkin f1d0f15a6d virtio: backend virtqueue notifier masking 
some backends (notably vhost) can mask events
at their source in a way that is more efficient
than masking through kvm.
Specifically
- masking in kvm uses rcu write side so it has high latency
- in kvm on unmask we always send an interrupt
masking at source does not have these issues.

Add such support in virtio.h and use in virtio-pci.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2013-01-07 19:42:23 +02:00

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/*
* Virtio Support
*
* Copyright IBM, Corp. 2007
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef _QEMU_VIRTIO_H
#define _QEMU_VIRTIO_H
#include "hw.h"
#include "net/net.h"
#include "qdev.h"
#include "sysemu/sysemu.h"
#include "qemu/event_notifier.h"
#ifdef CONFIG_LINUX
#include "9p.h"
#endif
/* from Linux's linux/virtio_config.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
/* Some virtio feature bits (currently bits 28 through 31) are reserved for the
* transport being used (eg. virtio_ring), the rest are per-device feature bits. */
#define VIRTIO_TRANSPORT_F_START 28
#define VIRTIO_TRANSPORT_F_END 32
/* We notify when the ring is completely used, even if the guest is suppressing
* callbacks */
#define VIRTIO_F_NOTIFY_ON_EMPTY 24
/* We support indirect buffer descriptors */
#define VIRTIO_RING_F_INDIRECT_DESC 28
/* The Guest publishes the used index for which it expects an interrupt
* at the end of the avail ring. Host should ignore the avail->flags field. */
/* The Host publishes the avail index for which it expects a kick
* at the end of the used ring. Guest should ignore the used->flags field. */
#define VIRTIO_RING_F_EVENT_IDX 29
/* A guest should never accept this. It implies negotiation is broken. */
#define VIRTIO_F_BAD_FEATURE 30
/* from Linux's linux/virtio_ring.h */
/* This marks a buffer as continuing via the next field. */
#define VRING_DESC_F_NEXT 1
/* This marks a buffer as write-only (otherwise read-only). */
#define VRING_DESC_F_WRITE 2
/* This means the buffer contains a list of buffer descriptors. */
#define VRING_DESC_F_INDIRECT 4
/* This means don't notify other side when buffer added. */
#define VRING_USED_F_NO_NOTIFY 1
/* This means don't interrupt guest when buffer consumed. */
#define VRING_AVAIL_F_NO_INTERRUPT 1
struct VirtQueue;
static inline hwaddr vring_align(hwaddr addr,
unsigned long align)
{
return (addr + align - 1) & ~(align - 1);
}
typedef struct VirtQueue VirtQueue;
#define VIRTQUEUE_MAX_SIZE 1024
typedef struct VirtQueueElement
{
unsigned int index;
unsigned int out_num;
unsigned int in_num;
hwaddr in_addr[VIRTQUEUE_MAX_SIZE];
hwaddr out_addr[VIRTQUEUE_MAX_SIZE];
struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
} VirtQueueElement;
typedef struct {
void (*notify)(DeviceState *d, uint16_t vector);
void (*save_config)(DeviceState *d, QEMUFile *f);
void (*save_queue)(DeviceState *d, int n, QEMUFile *f);
int (*load_config)(DeviceState *d, QEMUFile *f);
int (*load_queue)(DeviceState *d, int n, QEMUFile *f);
int (*load_done)(DeviceState *d, QEMUFile *f);
unsigned (*get_features)(DeviceState *d);
bool (*query_guest_notifiers)(DeviceState *d);
int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assigned);
int (*set_host_notifier)(DeviceState *d, int n, bool assigned);
void (*vmstate_change)(DeviceState *d, bool running);
} VirtIOBindings;
#define VIRTIO_PCI_QUEUE_MAX 64
#define VIRTIO_NO_VECTOR 0xffff
struct VirtIODevice
{
const char *name;
uint8_t status;
uint8_t isr;
uint16_t queue_sel;
uint32_t guest_features;
size_t config_len;
void *config;
uint16_t config_vector;
int nvectors;
uint32_t (*get_features)(VirtIODevice *vdev, uint32_t requested_features);
uint32_t (*bad_features)(VirtIODevice *vdev);
void (*set_features)(VirtIODevice *vdev, uint32_t val);
void (*get_config)(VirtIODevice *vdev, uint8_t *config);
void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
void (*reset)(VirtIODevice *vdev);
void (*set_status)(VirtIODevice *vdev, uint8_t val);
/* Test and clear event pending status.
* Should be called after unmask to avoid losing events.
* If backend does not support masking,
* must check in frontend instead.
*/
bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
/* Mask/unmask events from this vq. Any events reported
* while masked will become pending.
* If backend does not support masking,
* must mask in frontend instead.
*/
void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
VirtQueue *vq;
const VirtIOBindings *binding;
DeviceState *binding_opaque;
uint16_t device_id;
bool vm_running;
VMChangeStateEntry *vmstate;
};
VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
void (*handle_output)(VirtIODevice *,
VirtQueue *));
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len);
void virtqueue_flush(VirtQueue *vq, unsigned int count);
void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx);
void virtqueue_map_sg(struct iovec *sg, hwaddr *addr,
size_t num_sg, int is_write);
int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes,
unsigned int out_bytes);
void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
unsigned int *out_bytes,
unsigned max_in_bytes, unsigned max_out_bytes);
void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
void virtio_save(VirtIODevice *vdev, QEMUFile *f);
int virtio_load(VirtIODevice *vdev, QEMUFile *f);
void virtio_cleanup(VirtIODevice *vdev);
void virtio_notify_config(VirtIODevice *vdev);
void virtio_queue_set_notification(VirtQueue *vq, int enable);
int virtio_queue_ready(VirtQueue *vq);
int virtio_queue_empty(VirtQueue *vq);
/* Host binding interface. */
VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
size_t config_size, size_t struct_size);
uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr);
uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr);
uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr);
void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data);
void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data);
void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data);
void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
int virtio_queue_get_num(VirtIODevice *vdev, int n);
void virtio_queue_notify(VirtIODevice *vdev, int n);
uint16_t virtio_queue_vector(VirtIODevice *vdev, int n);
void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector);
void virtio_set_status(VirtIODevice *vdev, uint8_t val);
void virtio_reset(void *opaque);
void virtio_update_irq(VirtIODevice *vdev);
int virtio_set_features(VirtIODevice *vdev, uint32_t val);
void virtio_bind_device(VirtIODevice *vdev, const VirtIOBindings *binding,
DeviceState *opaque);
/* Base devices. */
typedef struct VirtIOBlkConf VirtIOBlkConf;
VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk);
struct virtio_net_conf;
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
struct virtio_net_conf *net);
typedef struct virtio_serial_conf virtio_serial_conf;
VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *serial);
VirtIODevice *virtio_balloon_init(DeviceState *dev);
typedef struct VirtIOSCSIConf VirtIOSCSIConf;
VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *conf);
typedef struct VirtIORNGConf VirtIORNGConf;
VirtIODevice *virtio_rng_init(DeviceState *dev, VirtIORNGConf *conf);
#ifdef CONFIG_LINUX
VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf);
#endif
void virtio_net_exit(VirtIODevice *vdev);
void virtio_blk_exit(VirtIODevice *vdev);
void virtio_serial_exit(VirtIODevice *vdev);
void virtio_balloon_exit(VirtIODevice *vdev);
void virtio_scsi_exit(VirtIODevice *vdev);
void virtio_rng_exit(VirtIODevice *vdev);
#define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
DEFINE_PROP_BIT("indirect_desc", _state, _field, \
VIRTIO_RING_F_INDIRECT_DESC, true), \
DEFINE_PROP_BIT("event_idx", _state, _field, \
VIRTIO_RING_F_EVENT_IDX, true)
hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_ring_addr(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
hwaddr virtio_queue_get_ring_size(VirtIODevice *vdev, int n);
uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
int virtio_queue_get_id(VirtQueue *vq);
EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
bool with_irqfd);
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
bool set_handler);
void virtio_queue_notify_vq(VirtQueue *vq);
void virtio_irq(VirtQueue *vq);
#endif
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