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-rw-r--r--hw/dataplane/vring.c363
1 files changed, 0 insertions, 363 deletions
diff --git a/hw/dataplane/vring.c b/hw/dataplane/vring.c
deleted file mode 100644
index e3b225315f..0000000000
--- a/hw/dataplane/vring.c
+++ /dev/null
@@ -1,363 +0,0 @@
-/* Copyright 2012 Red Hat, Inc.
- * Copyright IBM, Corp. 2012
- *
- * Based on Linux 2.6.39 vhost code:
- * Copyright (C) 2009 Red Hat, Inc.
- * Copyright (C) 2006 Rusty Russell IBM Corporation
- *
- * Author: Michael S. Tsirkin <mst@redhat.com>
- * Stefan Hajnoczi <stefanha@redhat.com>
- *
- * Inspiration, some code, and most witty comments come from
- * Documentation/virtual/lguest/lguest.c, by Rusty Russell
- *
- * This work is licensed under the terms of the GNU GPL, version 2.
- */
-
-#include "trace.h"
-#include "vring.h"
-#include "qemu/error-report.h"
-
-/* Map the guest's vring to host memory */
-bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
-{
- hwaddr vring_addr = virtio_queue_get_ring_addr(vdev, n);
- hwaddr vring_size = virtio_queue_get_ring_size(vdev, n);
- void *vring_ptr;
-
- vring->broken = false;
-
- hostmem_init(&vring->hostmem);
- vring_ptr = hostmem_lookup(&vring->hostmem, vring_addr, vring_size, true);
- if (!vring_ptr) {
- error_report("Failed to map vring "
- "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
- vring_addr, vring_size);
- vring->broken = true;
- return false;
- }
-
- vring_init(&vring->vr, virtio_queue_get_num(vdev, n), vring_ptr, 4096);
-
- vring->last_avail_idx = 0;
- vring->last_used_idx = 0;
- vring->signalled_used = 0;
- vring->signalled_used_valid = false;
-
- trace_vring_setup(virtio_queue_get_ring_addr(vdev, n),
- vring->vr.desc, vring->vr.avail, vring->vr.used);
- return true;
-}
-
-void vring_teardown(Vring *vring)
-{
- hostmem_finalize(&vring->hostmem);
-}
-
-/* Disable guest->host notifies */
-void vring_disable_notification(VirtIODevice *vdev, Vring *vring)
-{
- if (!(vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX))) {
- vring->vr.used->flags |= VRING_USED_F_NO_NOTIFY;
- }
-}
-
-/* Enable guest->host notifies
- *
- * Return true if the vring is empty, false if there are more requests.
- */
-bool vring_enable_notification(VirtIODevice *vdev, Vring *vring)
-{
- if (vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
- vring_avail_event(&vring->vr) = vring->vr.avail->idx;
- } else {
- vring->vr.used->flags &= ~VRING_USED_F_NO_NOTIFY;
- }
- smp_mb(); /* ensure update is seen before reading avail_idx */
- return !vring_more_avail(vring);
-}
-
-/* This is stolen from linux/drivers/vhost/vhost.c:vhost_notify() */
-bool vring_should_notify(VirtIODevice *vdev, Vring *vring)
-{
- uint16_t old, new;
- bool v;
- /* Flush out used index updates. This is paired
- * with the barrier that the Guest executes when enabling
- * interrupts. */
- smp_mb();
-
- if ((vdev->guest_features & VIRTIO_F_NOTIFY_ON_EMPTY) &&
- unlikely(vring->vr.avail->idx == vring->last_avail_idx)) {
- return true;
- }
-
- if (!(vdev->guest_features & VIRTIO_RING_F_EVENT_IDX)) {
- return !(vring->vr.avail->flags & VRING_AVAIL_F_NO_INTERRUPT);
- }
- old = vring->signalled_used;
- v = vring->signalled_used_valid;
- new = vring->signalled_used = vring->last_used_idx;
- vring->signalled_used_valid = true;
-
- if (unlikely(!v)) {
- return true;
- }
-
- return vring_need_event(vring_used_event(&vring->vr), new, old);
-}
-
-/* This is stolen from linux/drivers/vhost/vhost.c. */
-static int get_indirect(Vring *vring,
- struct iovec iov[], struct iovec *iov_end,
- unsigned int *out_num, unsigned int *in_num,
- struct vring_desc *indirect)
-{
- struct vring_desc desc;
- unsigned int i = 0, count, found = 0;
-
- /* Sanity check */
- if (unlikely(indirect->len % sizeof(desc))) {
- error_report("Invalid length in indirect descriptor: "
- "len %#x not multiple of %#zx",
- indirect->len, sizeof(desc));
- vring->broken = true;
- return -EFAULT;
- }
-
- count = indirect->len / sizeof(desc);
- /* Buffers are chained via a 16 bit next field, so
- * we can have at most 2^16 of these. */
- if (unlikely(count > USHRT_MAX + 1)) {
- error_report("Indirect buffer length too big: %d", indirect->len);
- vring->broken = true;
- return -EFAULT;
- }
-
- do {
- struct vring_desc *desc_ptr;
-
- /* Translate indirect descriptor */
- desc_ptr = hostmem_lookup(&vring->hostmem,
- indirect->addr + found * sizeof(desc),
- sizeof(desc), false);
- if (!desc_ptr) {
- error_report("Failed to map indirect descriptor "
- "addr %#" PRIx64 " len %zu",
- (uint64_t)indirect->addr + found * sizeof(desc),
- sizeof(desc));
- vring->broken = true;
- return -EFAULT;
- }
- desc = *desc_ptr;
-
- /* Ensure descriptor has been loaded before accessing fields */
- barrier(); /* read_barrier_depends(); */
-
- if (unlikely(++found > count)) {
- error_report("Loop detected: last one at %u "
- "indirect size %u", i, count);
- vring->broken = true;
- return -EFAULT;
- }
-
- if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) {
- error_report("Nested indirect descriptor");
- vring->broken = true;
- return -EFAULT;
- }
-
- /* Stop for now if there are not enough iovecs available. */
- if (iov >= iov_end) {
- return -ENOBUFS;
- }
-
- iov->iov_base = hostmem_lookup(&vring->hostmem, desc.addr, desc.len,
- desc.flags & VRING_DESC_F_WRITE);
- if (!iov->iov_base) {
- error_report("Failed to map indirect descriptor"
- "addr %#" PRIx64 " len %u",
- (uint64_t)desc.addr, desc.len);
- vring->broken = true;
- return -EFAULT;
- }
- iov->iov_len = desc.len;
- iov++;
-
- /* If this is an input descriptor, increment that count. */
- if (desc.flags & VRING_DESC_F_WRITE) {
- *in_num += 1;
- } else {
- /* If it's an output descriptor, they're all supposed
- * to come before any input descriptors. */
- if (unlikely(*in_num)) {
- error_report("Indirect descriptor "
- "has out after in: idx %u", i);
- vring->broken = true;
- return -EFAULT;
- }
- *out_num += 1;
- }
- i = desc.next;
- } while (desc.flags & VRING_DESC_F_NEXT);
- return 0;
-}
-
-/* This looks in the virtqueue and for the first available buffer, and converts
- * it to an iovec for convenient access. Since descriptors consist of some
- * number of output then some number of input descriptors, it's actually two
- * iovecs, but we pack them into one and note how many of each there were.
- *
- * This function returns the descriptor number found, or vq->num (which is
- * never a valid descriptor number) if none was found. A negative code is
- * returned on error.
- *
- * Stolen from linux/drivers/vhost/vhost.c.
- */
-int vring_pop(VirtIODevice *vdev, Vring *vring,
- struct iovec iov[], struct iovec *iov_end,
- unsigned int *out_num, unsigned int *in_num)
-{
- struct vring_desc desc;
- unsigned int i, head, found = 0, num = vring->vr.num;
- uint16_t avail_idx, last_avail_idx;
-
- /* If there was a fatal error then refuse operation */
- if (vring->broken) {
- return -EFAULT;
- }
-
- /* Check it isn't doing very strange things with descriptor numbers. */
- last_avail_idx = vring->last_avail_idx;
- avail_idx = vring->vr.avail->idx;
- barrier(); /* load indices now and not again later */
-
- if (unlikely((uint16_t)(avail_idx - last_avail_idx) > num)) {
- error_report("Guest moved used index from %u to %u",
- last_avail_idx, avail_idx);
- vring->broken = true;
- return -EFAULT;
- }
-
- /* If there's nothing new since last we looked. */
- if (avail_idx == last_avail_idx) {
- return -EAGAIN;
- }
-
- /* Only get avail ring entries after they have been exposed by guest. */
- smp_rmb();
-
- /* Grab the next descriptor number they're advertising, and increment
- * the index we've seen. */
- head = vring->vr.avail->ring[last_avail_idx % num];
-
- /* If their number is silly, that's an error. */
- if (unlikely(head >= num)) {
- error_report("Guest says index %u > %u is available", head, num);
- vring->broken = true;
- return -EFAULT;
- }
-
- if (vdev->guest_features & (1 << VIRTIO_RING_F_EVENT_IDX)) {
- vring_avail_event(&vring->vr) = vring->vr.avail->idx;
- }
-
- /* When we start there are none of either input nor output. */
- *out_num = *in_num = 0;
-
- i = head;
- do {
- if (unlikely(i >= num)) {
- error_report("Desc index is %u > %u, head = %u", i, num, head);
- vring->broken = true;
- return -EFAULT;
- }
- if (unlikely(++found > num)) {
- error_report("Loop detected: last one at %u vq size %u head %u",
- i, num, head);
- vring->broken = true;
- return -EFAULT;
- }
- desc = vring->vr.desc[i];
-
- /* Ensure descriptor is loaded before accessing fields */
- barrier();
-
- if (desc.flags & VRING_DESC_F_INDIRECT) {
- int ret = get_indirect(vring, iov, iov_end, out_num, in_num, &desc);
- if (ret < 0) {
- return ret;
- }
- continue;
- }
-
- /* If there are not enough iovecs left, stop for now. The caller
- * should check if there are more descs available once they have dealt
- * with the current set.
- */
- if (iov >= iov_end) {
- return -ENOBUFS;
- }
-
- /* TODO handle non-contiguous memory across region boundaries */
- iov->iov_base = hostmem_lookup(&vring->hostmem, desc.addr, desc.len,
- desc.flags & VRING_DESC_F_WRITE);
- if (!iov->iov_base) {
- error_report("Failed to map vring desc addr %#" PRIx64 " len %u",
- (uint64_t)desc.addr, desc.len);
- vring->broken = true;
- return -EFAULT;
- }
- iov->iov_len = desc.len;
- iov++;
-
- if (desc.flags & VRING_DESC_F_WRITE) {
- /* If this is an input descriptor,
- * increment that count. */
- *in_num += 1;
- } else {
- /* If it's an output descriptor, they're all supposed
- * to come before any input descriptors. */
- if (unlikely(*in_num)) {
- error_report("Descriptor has out after in: idx %d", i);
- vring->broken = true;
- return -EFAULT;
- }
- *out_num += 1;
- }
- i = desc.next;
- } while (desc.flags & VRING_DESC_F_NEXT);
-
- /* On success, increment avail index. */
- vring->last_avail_idx++;
- return head;
-}
-
-/* After we've used one of their buffers, we tell them about it.
- *
- * Stolen from linux/drivers/vhost/vhost.c.
- */
-void vring_push(Vring *vring, unsigned int head, int len)
-{
- struct vring_used_elem *used;
- uint16_t new;
-
- /* Don't touch vring if a fatal error occurred */
- if (vring->broken) {
- return;
- }
-
- /* The virtqueue contains a ring of used buffers. Get a pointer to the
- * next entry in that used ring. */
- used = &vring->vr.used->ring[vring->last_used_idx % vring->vr.num];
- used->id = head;
- used->len = len;
-
- /* Make sure buffer is written before we update index. */
- smp_wmb();
-
- new = vring->vr.used->idx = ++vring->last_used_idx;
- if (unlikely((int16_t)(new - vring->signalled_used) < (uint16_t)1)) {
- vring->signalled_used_valid = false;
- }
-}
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