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vring: remove

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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2016-02-14 18:17:11 +01:00 committed by Michael S. Tsirkin
parent e24a47c5b7
commit fee089e4e2
6 changed files with 0 additions and 679 deletions
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1
hw/virtio/Makefile.objs
View File

@ -2,7 +2,6 @@ common-obj-y += virtio-rng.o
common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
common-obj-y += virtio-bus.o
common-obj-y += virtio-mmio.o
obj-$(CONFIG_VIRTIO) += dataplane/
obj-y += virtio.o virtio-balloon.o
obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o

1
hw/virtio/dataplane/Makefile.objs
View File

@ -1 +0,0 @@
obj-y += vring.o

548
hw/virtio/dataplane/vring.c
View File

@ -1,548 +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 "qemu/osdep.h"
#include "trace.h"
#include "hw/hw.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "hw/virtio/virtio-access.h"
#include "hw/virtio/dataplane/vring.h"
#include "hw/virtio/dataplane/vring-accessors.h"
#include "qemu/error-report.h"
/* vring_map can be coupled with vring_unmap or (if you still have the
* value returned in *mr) memory_region_unref.
* Returns NULL on failure.
* Callers that can handle a partial mapping must supply mapped_len pointer to
* get the actual length mapped.
* Passing mapped_len == NULL requires either a full mapping or a failure.
*/
static void *vring_map(MemoryRegion **mr, hwaddr phys,
hwaddr len, hwaddr *mapped_len,
bool is_write)
{
MemoryRegionSection section = memory_region_find(get_system_memory(), phys, len);
uint64_t size;
if (!section.mr) {
goto out;
}
size = int128_get64(section.size);
assert(size);
/* Passing mapped_len == NULL requires either a full mapping or a failure. */
if (!mapped_len && size < len) {
goto out;
}
if (is_write && section.readonly) {
goto out;
}
if (!memory_region_is_ram(section.mr)) {
goto out;
}
/* Ignore regions with dirty logging, we cannot mark them dirty */
if (memory_region_get_dirty_log_mask(section.mr)) {
goto out;
}
if (mapped_len) {
*mapped_len = MIN(size, len);
}
*mr = section.mr;
return memory_region_get_ram_ptr(section.mr) + section.offset_within_region;
out:
memory_region_unref(section.mr);
*mr = NULL;
return NULL;
}
static void vring_unmap(void *buffer, bool is_write)
{
ram_addr_t addr;
MemoryRegion *mr;
mr = qemu_ram_addr_from_host(buffer, &addr);
memory_region_unref(mr);
}
/* Map the guest's vring to host memory */
bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
{
struct vring *vr = &vring->vr;
hwaddr addr;
hwaddr size;
void *ptr;
vring->broken = false;
vr->num = virtio_queue_get_num(vdev, n);
addr = virtio_queue_get_desc_addr(vdev, n);
size = virtio_queue_get_desc_size(vdev, n);
/* Map the descriptor area as read only */
ptr = vring_map(&vring->mr_desc, addr, size, NULL, false);
if (!ptr) {
error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring desc "
"at 0x%" HWADDR_PRIx,
size, addr);
goto out_err_desc;
}
vr->desc = ptr;
addr = virtio_queue_get_avail_addr(vdev, n);
size = virtio_queue_get_avail_size(vdev, n);
/* Add the size of the used_event_idx */
size += sizeof(uint16_t);
/* Map the driver area as read only */
ptr = vring_map(&vring->mr_avail, addr, size, NULL, false);
if (!ptr) {
error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring avail "
"at 0x%" HWADDR_PRIx,
size, addr);
goto out_err_avail;
}
vr->avail = ptr;
addr = virtio_queue_get_used_addr(vdev, n);
size = virtio_queue_get_used_size(vdev, n);
/* Add the size of the avail_event_idx */
size += sizeof(uint16_t);
/* Map the device area as read-write */
ptr = vring_map(&vring->mr_used, addr, size, NULL, true);
if (!ptr) {
error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring used "
"at 0x%" HWADDR_PRIx,
size, addr);
goto out_err_used;
}
vr->used = ptr;
vring->last_avail_idx = virtio_queue_get_last_avail_idx(vdev, n);
vring->last_used_idx = vring_get_used_idx(vdev, vring);
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;
out_err_used:
memory_region_unref(vring->mr_avail);
out_err_avail:
memory_region_unref(vring->mr_desc);
out_err_desc:
vring->broken = true;
return false;
}
void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
{
virtio_queue_set_last_avail_idx(vdev, n, vring->last_avail_idx);
virtio_queue_invalidate_signalled_used(vdev, n);
memory_region_unref(vring->mr_desc);
memory_region_unref(vring->mr_avail);
memory_region_unref(vring->mr_used);
}
/* Disable guest->host notifies */
void vring_disable_notification(VirtIODevice *vdev, Vring *vring)
{
if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
vring_set_used_flags(vdev, vring, VRING_USED_F_NO_NOTIFY);
}
}
/* Enable guest->host notifies
*
* Return true if the vring is empty, false if there are more requests.
*/
void vring_enable_notification(VirtIODevice *vdev, Vring *vring)
{
if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
vring_avail_event(&vring->vr) = vring->vr.avail->idx;
} else {
vring_clear_used_flags(vdev, vring, VRING_USED_F_NO_NOTIFY);
}
smp_mb(); /* ensure update is seen before reading avail_idx */
}
/* 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 (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
unlikely(!vring_more_avail(vdev, vring))) {
return true;
}
if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
return !(vring_get_avail_flags(vdev, vring) &
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(virtio_tswap16(vdev, vring_used_event(&vring->vr)),
new, old);
}
typedef struct VirtQueueCurrentElement {
unsigned in_num;
unsigned out_num;
hwaddr addr[VIRTQUEUE_MAX_SIZE];
struct iovec iov[VIRTQUEUE_MAX_SIZE];
} VirtQueueCurrentElement;
static int get_desc(Vring *vring, VirtQueueCurrentElement *elem,
struct vring_desc *desc)
{
unsigned *num;
struct iovec *iov;
hwaddr *addr;
MemoryRegion *mr;
hwaddr len;
if (desc->flags & VRING_DESC_F_WRITE) {
num = &elem->in_num;
iov = &elem->iov[elem->out_num + *num];
addr = &elem->addr[elem->out_num + *num];
} else {
num = &elem->out_num;
iov = &elem->iov[*num];
addr = &elem->addr[*num];
/* If it's an output descriptor, they're all supposed
* to come before any input descriptors. */
if (unlikely(elem->in_num)) {
error_report("Descriptor has out after in");
return -EFAULT;
}
}
while (desc->len) {
/* Stop for now if there are not enough iovecs available. */
if (*num >= VIRTQUEUE_MAX_SIZE) {
error_report("Invalid SG num: %u", *num);
return -EFAULT;
}
iov->iov_base = vring_map(&mr, desc->addr, desc->len, &len,
desc->flags & VRING_DESC_F_WRITE);
if (!iov->iov_base) {
error_report("Failed to map descriptor addr %#" PRIx64 " len %u",
(uint64_t)desc->addr, desc->len);
return -EFAULT;
}
/* The MemoryRegion is looked up again and unref'ed later, leave the
* ref in place. */
(iov++)->iov_len = len;
*addr++ = desc->addr;
desc->len -= len;
desc->addr += len;
*num += 1;
}
return 0;
}
static void copy_in_vring_desc(VirtIODevice *vdev,
const struct vring_desc *guest,
struct vring_desc *host)
{
host->addr = virtio_ldq_p(vdev, &guest->addr);
host->len = virtio_ldl_p(vdev, &guest->len);
host->flags = virtio_lduw_p(vdev, &guest->flags);
host->next = virtio_lduw_p(vdev, &guest->next);
}
static bool read_vring_desc(VirtIODevice *vdev,
hwaddr guest,
struct vring_desc *host)
{
if (address_space_read(&address_space_memory, guest, MEMTXATTRS_UNSPECIFIED,
(uint8_t *)host, sizeof *host)) {
return false;
}
host->addr = virtio_tswap64(vdev, host->addr);
host->len = virtio_tswap32(vdev, host->len);
host->flags = virtio_tswap16(vdev, host->flags);
host->next = virtio_tswap16(vdev, host->next);
return true;
}
/* This is stolen from linux/drivers/vhost/vhost.c. */
static int get_indirect(VirtIODevice *vdev, Vring *vring,
VirtQueueCurrentElement *cur_elem,
struct vring_desc *indirect)
{
struct vring_desc desc;
unsigned int i = 0, count, found = 0;
int ret;
/* 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 {
/* Translate indirect descriptor */
if (!read_vring_desc(vdev, indirect->addr + found * sizeof(desc),
&desc)) {
error_report("Failed to read indirect descriptor "
"addr %#" PRIx64 " len %zu",
(uint64_t)indirect->addr + found * sizeof(desc),
sizeof(desc));
vring->broken = true;
return -EFAULT;
}
/* 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;
}
ret = get_desc(vring, cur_elem, &desc);
if (ret < 0) {
vring->broken |= (ret == -EFAULT);
return ret;
}
i = desc.next;
} while (desc.flags & VRING_DESC_F_NEXT);
return 0;
}
static void vring_unmap_element(VirtQueueElement *elem)
{
int i;
/* This assumes that the iovecs, if changed, are never moved past
* the end of the valid area. This is true if iovec manipulations
* are done with iov_discard_front and iov_discard_back.
*/
for (i = 0; i < elem->out_num; i++) {
vring_unmap(elem->out_sg[i].iov_base, false);
}
for (i = 0; i < elem->in_num; i++) {
vring_unmap(elem->in_sg[i].iov_base, true);
}
}
/* 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.
*/
void *vring_pop(VirtIODevice *vdev, Vring *vring, size_t sz)
{
struct vring_desc desc;
unsigned int i, head, found = 0, num = vring->vr.num;
uint16_t avail_idx, last_avail_idx;
VirtQueueCurrentElement cur_elem;
VirtQueueElement *elem = NULL;
int ret;
/* If there was a fatal error then refuse operation */
if (vring->broken) {
ret = -EFAULT;
goto out;
}
cur_elem.in_num = cur_elem.out_num = 0;
/* Check it isn't doing very strange things with descriptor numbers. */
last_avail_idx = vring->last_avail_idx;
avail_idx = vring_get_avail_idx(vdev, vring);
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);
ret = -EFAULT;
goto out;
}
/* If there's nothing new since last we looked. */
if (avail_idx == last_avail_idx) {
ret = -EAGAIN;
goto out;
}
/* 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_get_avail_ring(vdev, vring, 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);
ret = -EFAULT;
goto out;
}
i = head;
do {
if (unlikely(i >= num)) {
error_report("Desc index is %u > %u, head = %u", i, num, head);
ret = -EFAULT;
goto out;
}
if (unlikely(++found > num)) {
error_report("Loop detected: last one at %u vq size %u head %u",
i, num, head);
ret = -EFAULT;
goto out;
}
copy_in_vring_desc(vdev, &vring->vr.desc[i], &desc);
/* Ensure descriptor is loaded before accessing fields */
barrier();
if (desc.flags & VRING_DESC_F_INDIRECT) {
ret = get_indirect(vdev, vring, &cur_elem, &desc);
if (ret < 0) {
goto out;
}
continue;
}
ret = get_desc(vring, &cur_elem, &desc);
if (ret < 0) {
goto out;
}
i = desc.next;
} while (desc.flags & VRING_DESC_F_NEXT);
/* On success, increment avail index. */
vring->last_avail_idx++;
if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
vring_avail_event(&vring->vr) =
virtio_tswap16(vdev, vring->last_avail_idx);
}
/* Now copy what we have collected and mapped */
elem = virtqueue_alloc_element(sz, cur_elem.out_num, cur_elem.in_num);
elem->index = head;
for (i = 0; i < cur_elem.out_num; i++) {
elem->out_addr[i] = cur_elem.addr[i];
elem->out_sg[i] = cur_elem.iov[i];
}
for (i = 0; i < cur_elem.in_num; i++) {
elem->in_addr[i] = cur_elem.addr[cur_elem.out_num + i];
elem->in_sg[i] = cur_elem.iov[cur_elem.out_num + i];
}
return elem;
out:
assert(ret < 0);
if (ret == -EFAULT) {
vring->broken = true;
}
for (i = 0; i < cur_elem.out_num + cur_elem.in_num; i++) {
vring_unmap(cur_elem.iov[i].iov_base, false);
}
g_free(elem);
return NULL;
}
/* After we've used one of their buffers, we tell them about it.
*
* Stolen from linux/drivers/vhost/vhost.c.
*/
void vring_push(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem,
int len)
{
unsigned int head = elem->index;
uint16_t new;
vring_unmap_element(elem);
/* 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. */
vring_set_used_ring_id(vdev, vring, vring->last_used_idx % vring->vr.num,
head);
vring_set_used_ring_len(vdev, vring, vring->last_used_idx % vring->vr.num,
len);
/* Make sure buffer is written before we update index. */
smp_wmb();
new = ++vring->last_used_idx;
vring_set_used_idx(vdev, vring, new);
if (unlikely((int16_t)(new - vring->signalled_used) < (uint16_t)1)) {
vring->signalled_used_valid = false;
}
}

75
include/hw/virtio/dataplane/vring-accessors.h
View File

@ -1,75 +0,0 @@
#ifndef VRING_ACCESSORS_H
#define VRING_ACCESSORS_H
#include "standard-headers/linux/virtio_ring.h"
#include "hw/virtio/virtio.h"
#include "hw/virtio/virtio-access.h"
static inline uint16_t vring_get_used_idx(VirtIODevice *vdev, Vring *vring)
{
return virtio_tswap16(vdev, vring->vr.used->idx);
}
static inline void vring_set_used_idx(VirtIODevice *vdev, Vring *vring,
uint16_t idx)
{
vring->vr.used->idx = virtio_tswap16(vdev, idx);
}
static inline uint16_t vring_get_avail_idx(VirtIODevice *vdev, Vring *vring)
{
return virtio_tswap16(vdev, vring->vr.avail->idx);
}
static inline uint16_t vring_get_avail_ring(VirtIODevice *vdev, Vring *vring,
int i)
{
return virtio_tswap16(vdev, vring->vr.avail->ring[i]);
}
static inline void vring_set_used_ring_id(VirtIODevice *vdev, Vring *vring,
int i, uint32_t id)
{
vring->vr.used->ring[i].id = virtio_tswap32(vdev, id);
}
static inline void vring_set_used_ring_len(VirtIODevice *vdev, Vring *vring,
int i, uint32_t len)
{
vring->vr.used->ring[i].len = virtio_tswap32(vdev, len);
}
static inline uint16_t vring_get_used_flags(VirtIODevice *vdev, Vring *vring)
{
return virtio_tswap16(vdev, vring->vr.used->flags);
}
static inline uint16_t vring_get_avail_flags(VirtIODevice *vdev, Vring *vring)
{
return virtio_tswap16(vdev, vring->vr.avail->flags);
}
static inline void vring_set_used_flags(VirtIODevice *vdev, Vring *vring,
uint16_t flags)
{
vring->vr.used->flags |= virtio_tswap16(vdev, flags);
}
static inline void vring_clear_used_flags(VirtIODevice *vdev, Vring *vring,
uint16_t flags)
{
vring->vr.used->flags &= virtio_tswap16(vdev, ~flags);
}
static inline unsigned int vring_get_num(Vring *vring)
{
return vring->vr.num;
}
/* Are there more descriptors available? */
static inline bool vring_more_avail(VirtIODevice *vdev, Vring *vring)
{
return vring_get_avail_idx(vdev, vring) != vring->last_avail_idx;
}
#endif

51
include/hw/virtio/dataplane/vring.h
View File

@ -1,51 +0,0 @@
/* Copyright 2012 Red Hat, Inc. and/or its affiliates
* 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.
*/
#ifndef VRING_H
#define VRING_H
#include "qemu-common.h"
#include "standard-headers/linux/virtio_ring.h"
#include "hw/virtio/virtio.h"
typedef struct {
MemoryRegion *mr_desc; /* memory region for the vring desc */
MemoryRegion *mr_avail; /* memory region for the vring avail */
MemoryRegion *mr_used; /* memory region for the vring used */
struct vring vr; /* virtqueue vring mapped to host memory */
uint16_t last_avail_idx; /* last processed avail ring index */
uint16_t last_used_idx; /* last processed used ring index */
uint16_t signalled_used; /* EVENT_IDX state */
bool signalled_used_valid;
bool broken; /* was there a fatal error? */
} Vring;
/* Fail future vring_pop() and vring_push() calls until reset */
static inline void vring_set_broken(Vring *vring)
{
vring->broken = true;
}
bool vring_setup(Vring *vring, VirtIODevice *vdev, int n);
void vring_teardown(Vring *vring, VirtIODevice *vdev, int n);
void vring_disable_notification(VirtIODevice *vdev, Vring *vring);
void vring_enable_notification(VirtIODevice *vdev, Vring *vring);
bool vring_should_notify(VirtIODevice *vdev, Vring *vring);
void *vring_pop(VirtIODevice *vdev, Vring *vring, size_t sz);
void vring_push(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem,
int len);
#endif /* VRING_H */

3
trace-events
View File

@ -127,9 +127,6 @@ virtio_blk_data_plane_start(void *s) "dataplane %p"
virtio_blk_data_plane_stop(void *s) "dataplane %p"
virtio_blk_data_plane_process_request(void *s, unsigned int out_num, unsigned int in_num, unsigned int head) "dataplane %p out_num %u in_num %u head %u"
# hw/virtio/dataplane/vring.c
vring_setup(uint64_t physical, void *desc, void *avail, void *used) "vring physical %#"PRIx64" desc %p avail %p used %p"
# thread-pool.c
thread_pool_submit(void *pool, void *req, void *opaque) "pool %p req %p opaque %p"
thread_pool_complete(void *pool, void *req, void *opaque, int ret) "pool %p req %p opaque %p ret %d"