mirror of
https://github.com/clearlinux/kvmtool.git
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Asias He
627d68743d
If vhost is enabled for a virtio device, vhost will poll the ioeventfd in kernel side and there is no need to poll it in userspace. Otherwise, both vhost kernel and userspace will race to poll. Signed-off-by: Asias He <asias.hejun@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
104 lines
3.4 KiB
C
104 lines
3.4 KiB
C
#ifndef KVM__VIRTIO_H
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#define KVM__VIRTIO_H
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#include <linux/virtio_ring.h>
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#include <linux/virtio_pci.h>
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#include <linux/types.h>
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#include <sys/uio.h>
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#include "kvm/kvm.h"
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#define VIRTIO_IRQ_LOW 0
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#define VIRTIO_IRQ_HIGH 1
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#define VIRTIO_PCI_O_CONFIG 0
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#define VIRTIO_PCI_O_MSIX 1
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struct virt_queue {
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struct vring vring;
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u32 pfn;
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/* The last_avail_idx field is an index to ->ring of struct vring_avail.
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It's where we assume the next request index is at. */
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u16 last_avail_idx;
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u16 last_used_signalled;
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};
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static inline u16 virt_queue__pop(struct virt_queue *queue)
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{
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return queue->vring.avail->ring[queue->last_avail_idx++ % queue->vring.num];
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}
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static inline struct vring_desc *virt_queue__get_desc(struct virt_queue *queue, u16 desc_ndx)
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{
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return &queue->vring.desc[desc_ndx];
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}
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static inline bool virt_queue__available(struct virt_queue *vq)
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{
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if (!vq->vring.avail)
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return 0;
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vring_avail_event(&vq->vring) = vq->last_avail_idx;
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return vq->vring.avail->idx != vq->last_avail_idx;
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}
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/*
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* Warning: on 32-bit hosts, shifting pfn left may cause a truncation of pfn values
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* higher than 4GB - thus, pointing to the wrong area in guest virtual memory space
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* and breaking the virt queue which owns this pfn.
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*/
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static inline void *guest_pfn_to_host(struct kvm *kvm, u32 pfn)
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{
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return guest_flat_to_host(kvm, (unsigned long)pfn << VIRTIO_PCI_QUEUE_ADDR_SHIFT);
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}
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struct vring_used_elem *virt_queue__set_used_elem(struct virt_queue *queue, u32 head, u32 len);
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bool virtio_queue__should_signal(struct virt_queue *vq);
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u16 virt_queue__get_iov(struct virt_queue *vq, struct iovec iov[],
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u16 *out, u16 *in, struct kvm *kvm);
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u16 virt_queue__get_head_iov(struct virt_queue *vq, struct iovec iov[],
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u16 *out, u16 *in, u16 head, struct kvm *kvm);
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u16 virt_queue__get_inout_iov(struct kvm *kvm, struct virt_queue *queue,
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struct iovec in_iov[], struct iovec out_iov[],
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u16 *in, u16 *out);
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int virtio__get_dev_specific_field(int offset, bool msix, u32 *config_off);
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enum virtio_trans {
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VIRTIO_PCI,
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VIRTIO_MMIO,
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};
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struct virtio_device {
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bool use_vhost;
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void *virtio;
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struct virtio_ops *ops;
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};
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struct virtio_ops {
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void (*set_config)(struct kvm *kvm, void *dev, u8 data, u32 offset);
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u8 (*get_config)(struct kvm *kvm, void *dev, u32 offset);
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u32 (*get_host_features)(struct kvm *kvm, void *dev);
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void (*set_guest_features)(struct kvm *kvm, void *dev, u32 features);
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int (*init_vq)(struct kvm *kvm, void *dev, u32 vq, u32 pfn);
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int (*notify_vq)(struct kvm *kvm, void *dev, u32 vq);
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int (*get_pfn_vq)(struct kvm *kvm, void *dev, u32 vq);
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int (*get_size_vq)(struct kvm *kvm, void *dev, u32 vq);
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int (*set_size_vq)(struct kvm *kvm, void *dev, u32 vq, int size);
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void (*notify_vq_gsi)(struct kvm *kvm, void *dev, u32 vq, u32 gsi);
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void (*notify_vq_eventfd)(struct kvm *kvm, void *dev, u32 vq, u32 efd);
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int (*signal_vq)(struct kvm *kvm, struct virtio_device *vdev, u32 queueid);
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int (*signal_config)(struct kvm *kvm, struct virtio_device *vdev);
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int (*init)(struct kvm *kvm, void *dev, struct virtio_device *vdev,
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int device_id, int subsys_id, int class);
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int (*exit)(struct kvm *kvm, struct virtio_device *vdev);
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};
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int virtio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
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struct virtio_ops *ops, enum virtio_trans trans,
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int device_id, int subsys_id, int class);
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int virtio_compat_add_message(const char *device, const char *config);
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#endif /* KVM__VIRTIO_H */
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