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https://github.com/xcat2/xNBA.git
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e4419ff97c
This patch adds a native iPXE virtio-net driver and removes the legacy Etherboot virtio-net driver. The main reasons for doing this are: 1. Multiple virtio-net NICs are now supported by iPXE. The legacy driver kept global state and caused issues in virtual machines with more than one virtio-net device. 2. Faster downloads. The native iPXE driver downloads 100 MB over HTTP in 12s, the legacy Etherboot driver in 37s. This simple benchmark uses KVM with tap networking and the Python SimpleHTTPServer both running on the same host. Changes to core virtio code reduce vring descriptors to 256 (QEMU uses 128 for virtio-blk and 256 for virtio-net) and change the opaque token from u16 to void*. Lowering the descriptor count reduces memory consumption. The void* opaque token change makes driver code simpler. Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com> Signed-off-by: Michael Brown <mcb30@ipxe.org>
143 lines
3.2 KiB
C
143 lines
3.2 KiB
C
#ifndef _VIRTIO_RING_H_
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# define _VIRTIO_RING_H_
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#define PAGE_SHIFT (12)
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#define PAGE_SIZE (1<<PAGE_SHIFT)
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#define PAGE_MASK (PAGE_SIZE-1)
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/* Status byte for guest to report progress, and synchronize features. */
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/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
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#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
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/* We have found a driver for the device. */
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#define VIRTIO_CONFIG_S_DRIVER 2
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/* Driver has used its parts of the config, and is happy */
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#define VIRTIO_CONFIG_S_DRIVER_OK 4
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/* We've given up on this device. */
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#define VIRTIO_CONFIG_S_FAILED 0x80
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#define MAX_QUEUE_NUM (256)
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#define VRING_DESC_F_NEXT 1
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#define VRING_DESC_F_WRITE 2
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#define VRING_AVAIL_F_NO_INTERRUPT 1
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#define VRING_USED_F_NO_NOTIFY 1
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struct vring_desc
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{
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u64 addr;
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u32 len;
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u16 flags;
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u16 next;
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};
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struct vring_avail
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{
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u16 flags;
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u16 idx;
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u16 ring[0];
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};
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struct vring_used_elem
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{
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u32 id;
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u32 len;
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};
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struct vring_used
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{
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u16 flags;
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u16 idx;
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struct vring_used_elem ring[];
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};
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struct vring {
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unsigned int num;
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struct vring_desc *desc;
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struct vring_avail *avail;
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struct vring_used *used;
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};
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#define vring_size(num) \
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(((((sizeof(struct vring_desc) * num) + \
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(sizeof(struct vring_avail) + sizeof(u16) * num)) \
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+ PAGE_MASK) & ~PAGE_MASK) + \
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(sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num))
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typedef unsigned char virtio_queue_t[PAGE_MASK + vring_size(MAX_QUEUE_NUM)];
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struct vring_virtqueue {
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virtio_queue_t queue;
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struct vring vring;
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u16 free_head;
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u16 last_used_idx;
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void *vdata[MAX_QUEUE_NUM];
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/* PCI */
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int queue_index;
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};
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struct vring_list {
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char *addr;
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unsigned int length;
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};
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static inline void vring_init(struct vring *vr,
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unsigned int num, unsigned char *queue)
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{
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unsigned int i;
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unsigned long pa;
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vr->num = num;
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/* physical address of desc must be page aligned */
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pa = virt_to_phys(queue);
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pa = (pa + PAGE_MASK) & ~PAGE_MASK;
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vr->desc = phys_to_virt(pa);
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vr->avail = (struct vring_avail *)&vr->desc[num];
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/* physical address of used must be page aligned */
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pa = virt_to_phys(&vr->avail->ring[num]);
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pa = (pa + PAGE_MASK) & ~PAGE_MASK;
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vr->used = phys_to_virt(pa);
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for (i = 0; i < num - 1; i++)
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vr->desc[i].next = i + 1;
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vr->desc[i].next = 0;
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}
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static inline void vring_enable_cb(struct vring_virtqueue *vq)
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{
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vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
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}
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static inline void vring_disable_cb(struct vring_virtqueue *vq)
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{
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vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
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}
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/*
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* vring_more_used
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*
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* is there some used buffers ?
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*
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*/
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static inline int vring_more_used(struct vring_virtqueue *vq)
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{
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wmb();
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return vq->last_used_idx != vq->vring.used->idx;
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}
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void vring_detach(struct vring_virtqueue *vq, unsigned int head);
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void *vring_get_buf(struct vring_virtqueue *vq, unsigned int *len);
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void vring_add_buf(struct vring_virtqueue *vq, struct vring_list list[],
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unsigned int out, unsigned int in,
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void *index, int num_added);
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void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added);
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#endif /* _VIRTIO_RING_H_ */
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