qemu/hw/vhost.h
mst@redhat.com 5430a28fe4 vhost: force vhost off for non-MSI guests
When MSI is off, each interrupt needs to be bounced through the io
thread when it's set/cleared, so vhost-net causes more context switches and
higher CPU utilization than userspace virtio which handles networking in
the same thread.

We'll need to fix this by adding level irq support in kvm irqfd,
for now disable vhost-net in these configurations.

Added a vhostforce flag to force vhost-net back on.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-02-01 16:50:44 -06:00

51 lines
1.3 KiB
C

#ifndef VHOST_H
#define VHOST_H
#include "hw/hw.h"
#include "hw/virtio.h"
/* Generic structures common for any vhost based device. */
struct vhost_virtqueue {
int kick;
int call;
void *desc;
void *avail;
void *used;
int num;
unsigned long long used_phys;
unsigned used_size;
void *ring;
unsigned long long ring_phys;
unsigned ring_size;
};
typedef unsigned long vhost_log_chunk_t;
#define VHOST_LOG_PAGE 0x1000
#define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t))
#define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS)
struct vhost_memory;
struct vhost_dev {
CPUPhysMemoryClient client;
int control;
struct vhost_memory *mem;
struct vhost_virtqueue *vqs;
int nvqs;
unsigned long long features;
unsigned long long acked_features;
unsigned long long backend_features;
bool started;
bool log_enabled;
vhost_log_chunk_t *log;
unsigned long long log_size;
bool force;
};
int vhost_dev_init(struct vhost_dev *hdev, int devfd, bool force);
void vhost_dev_cleanup(struct vhost_dev *hdev);
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev);
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
#endif