tools/kvm/include/kvm/virtio.h

   1 #ifndef KVM__VIRTIO_H
   2 #define KVM__VIRTIO_H
   3
   4 #include <linux/virtio_ring.h>
   5 #include <linux/virtio_pci.h>
   6
   7 #include <linux/types.h>
   8 #include <sys/uio.h>
   9
  10 #include "kvm/kvm.h"
  11
  12 #define VIRTIO_IRQ_LOW          0
  13 #define VIRTIO_IRQ_HIGH         1
  14
  15 #define VIRTIO_PCI_O_CONFIG     0
  16 #define VIRTIO_PCI_O_MSIX       1
  17 #define VIRTIO_PCI_O_FEATURES   2
  18
  19 struct virt_queue {
  20         struct vring    vring;
  21         u32             pfn;
  22         /* The last_avail_idx field is an index to ->ring of struct vring_avail.
  23            It's where we assume the next request index is at.  */
  24         u16             last_avail_idx;
  25 };
  26
  27 static inline u16 virt_queue__pop(struct virt_queue *queue)
  28 {
  29         return queue->vring.avail->ring[queue->last_avail_idx++ % queue->vring.num];
  30 }
  31
  32 static inline struct vring_desc *virt_queue__get_desc(struct virt_queue *queue, u16 desc_ndx)
  33 {
  34         return &queue->vring.desc[desc_ndx];
  35 }
  36
  37 static inline bool virt_queue__available(struct virt_queue *vq)
  38 {
  39         if (!vq->vring.avail)
  40                 return 0;
  41         return vq->vring.avail->idx !=  vq->last_avail_idx;
  42 }
  43
  44 /*
  45  * Warning: on 32-bit hosts, shifting pfn left may cause a truncation of pfn values
  46  * higher than 4GB - thus, pointing to the wrong area in guest virtual memory space
  47  * and breaking the virt queue which owns this pfn.
  48  */
  49 static inline void *guest_pfn_to_host(struct kvm *kvm, u32 pfn)
  50 {
  51         return guest_flat_to_host(kvm, (unsigned long)pfn << VIRTIO_PCI_QUEUE_ADDR_SHIFT);
  52 }
  53
  54 struct vring_used_elem *virt_queue__set_used_elem(struct virt_queue *queue, u32 head, u32 len);
  55
  56 u16 virt_queue__get_iov(struct virt_queue *queue, struct iovec iov[], u16 *out, u16 *in, struct kvm *kvm);
  57 u16 virt_queue__get_inout_iov(struct kvm *kvm, struct virt_queue *queue,
  58                               struct iovec in_iov[], struct iovec out_iov[],
  59                               u16 *in, u16 *out);
  60
  61 void virt_queue__trigger_irq(struct virt_queue *vq, int irq, u8 *isr, struct kvm *kvm);
  62
  63 int virtio__get_dev_specific_field(int offset, bool msix, bool features_hi, u32 *config_off);
  64
  65 #endif /* KVM__VIRTIO_H */