OpenE2K/qemu-e2k
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Merge remote-tracking branch 'stefanha/block' into staging

Browse Source 
* stefanha/block:
  sheepdog: pass oid directly to send_pending_req()
  sheepdog: don't update inode when create_and_write fails
  block/raw-win32: Fix compiler warnings (wrong format specifiers)
  qemu-img: report size overflow error message
  cutils: change strtosz_suffix_unit function
  virtio-blk: Return UNSUPP for unknown request types
  virtio-blk: add x-data-plane=on|off performance feature
  dataplane: add virtio-blk data plane code
  virtio-blk: restore VirtIOBlkConf->config_wce flag
  iov: add qemu_iovec_concat_iov()
  test-iov: add iov_discard_front/back() testcases
  iov: add iov_discard_front/back() to remove data
  dataplane: add Linux AIO request queue
  dataplane: add event loop
  dataplane: add virtqueue vring code
  dataplane: add host memory mapping code
  configure: add CONFIG_VIRTIO_BLK_DATA_PLANE
  raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2013-01-02 12:19:27 -06:00
commit 217da7fdeb
27 changed files with 1867 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
block/raw-posix.c
View File

@ -1776,6 +1776,40 @@ static BlockDriver bdrv_host_cdrom = {
};
#endif /* __FreeBSD__ */
#ifdef CONFIG_LINUX_AIO
/**
* Return the file descriptor for Linux AIO
*
* This function is a layering violation and should be removed when it becomes
* possible to call the block layer outside the global mutex. It allows the
* caller to hijack the file descriptor so I/O can be performed outside the
* block layer.
*/
int raw_get_aio_fd(BlockDriverState *bs)
{
BDRVRawState *s;
if (!bs->drv) {
return -ENOMEDIUM;
}
if (bs->drv == bdrv_find_format("raw")) {
bs = bs->file;
}
/* raw-posix has several protocols so just check for raw_aio_readv */
if (bs->drv->bdrv_aio_readv != raw_aio_readv) {
return -ENOTSUP;
}
s = bs->opaque;
if (!s->use_aio) {
return -ENOTSUP;
}
return s->fd;
}
#endif /* CONFIG_LINUX_AIO */
static void bdrv_file_init(void)
{
/*

4
block/raw-win32.c
View File

@ -314,11 +314,11 @@ static int raw_truncate(BlockDriverState *bs, int64_t offset)
*/
dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
fprintf(stderr, "SetFilePointer error: %d\n", GetLastError());
fprintf(stderr, "SetFilePointer error: %lu\n", GetLastError());
return -EIO;
}
if (SetEndOfFile(s->hfile) == 0) {
fprintf(stderr, "SetEndOfFile error: %d\n", GetLastError());
fprintf(stderr, "SetEndOfFile error: %lu\n", GetLastError());
return -EIO;
}
return 0;

11
block/sheepdog.c
View File

@ -714,16 +714,17 @@ static void coroutine_fn aio_read_response(void *opaque)
* and max_dirty_data_idx are changed to include updated
* index between them.
*/
s->inode.data_vdi_id[idx] = s->inode.vdi_id;
s->max_dirty_data_idx = MAX(idx, s->max_dirty_data_idx);
s->min_dirty_data_idx = MIN(idx, s->min_dirty_data_idx);
if (rsp.result == SD_RES_SUCCESS) {
s->inode.data_vdi_id[idx] = s->inode.vdi_id;
s->max_dirty_data_idx = MAX(idx, s->max_dirty_data_idx);
s->min_dirty_data_idx = MIN(idx, s->min_dirty_data_idx);
}
/*
* Some requests may be blocked because simultaneous
* create requests are not allowed, so we search the
* pending requests here.
*/
send_pending_req(s, vid_to_data_oid(s->inode.vdi_id, idx));
send_pending_req(s, aio_req->oid);
}
break;
case AIOCB_READ_UDATA:

21
configure vendored
View File

@ -223,6 +223,7 @@ libiscsi=""
coroutine=""
seccomp=""
glusterfs=""
virtio_blk_data_plane=""
# parse CC options first
for opt do
@ -882,6 +883,10 @@ for opt do
;;
--enable-glusterfs) glusterfs="yes"
;;
--disable-virtio-blk-data-plane) virtio_blk_data_plane="no"
;;
--enable-virtio-blk-data-plane) virtio_blk_data_plane="yes"
;;
*) echo "ERROR: unknown option $opt"; show_help="yes"
;;
esac
@ -2273,6 +2278,17 @@ EOF
fi
fi
##########################################
# adjust virtio-blk-data-plane based on linux-aio
if test "$virtio_blk_data_plane" = "yes" -a \
"$linux_aio" != "yes" ; then
echo "Error: virtio-blk-data-plane requires Linux AIO, please try --enable-linux-aio"
exit 1
elif test -z "$virtio_blk_data_plane" ; then
virtio_blk_data_plane=$linux_aio
fi
##########################################
# attr probe
@ -3289,6 +3305,7 @@ echo "build guest agent $guest_agent"
echo "seccomp support $seccomp"
echo "coroutine backend $coroutine_backend"
echo "GlusterFS support $glusterfs"
echo "virtio-blk-data-plane $virtio_blk_data_plane"
if test "$sdl_too_old" = "yes"; then
echo "-> Your SDL version is too old - please upgrade to have SDL support"
@ -3634,6 +3651,10 @@ if test "$glusterfs" = "yes" ; then
echo "CONFIG_GLUSTERFS=y" >> $config_host_mak
fi
if test "$virtio_blk_data_plane" = "yes" ; then
echo "CONFIG_VIRTIO_BLK_DATA_PLANE=y" >> $config_host_mak
fi
# USB host support
case "$usb" in
linux)

6
cutils.c
View File

@ -214,12 +214,13 @@ static int64_t suffix_mul(char suffix, int64_t unit)
/*
* Convert string to bytes, allowing either B/b for bytes, K/k for KB,
* M/m for MB, G/g for GB or T/t for TB. End pointer will be returned
* in *end, if not NULL. Return -1 on error.
* in *end, if not NULL. Return -ERANGE on overflow, Return -EINVAL on
* other error.
*/
int64_t strtosz_suffix_unit(const char *nptr, char **end,
const char default_suffix, int64_t unit)
{
int64_t retval = -1;
int64_t retval = -EINVAL;
char *endptr;
unsigned char c;
int mul_required = 0;
@ -246,6 +247,7 @@ int64_t strtosz_suffix_unit(const char *nptr, char **end,
goto fail;
}
if ((val * mul >= INT64_MAX) || val < 0) {
retval = -ERANGE;
goto fail;
}
retval = val * mul;

2
hw/Makefile.objs
View File

@ -1,4 +1,4 @@
common-obj-y = usb/ ide/ pci/
common-obj-y = usb/ ide/ pci/ dataplane/
common-obj-y += loader.o
common-obj-$(CONFIG_VIRTIO) += virtio-console.o
common-obj-$(CONFIG_VIRTIO) += virtio-rng.o

3
hw/dataplane/Makefile.objs Normal file
View File

@ -0,0 +1,3 @@
ifeq ($(CONFIG_VIRTIO), y)
common-obj-$(CONFIG_VIRTIO_BLK_DATA_PLANE) += hostmem.o vring.o event-poll.o ioq.o virtio-blk.o
endif

100
hw/dataplane/event-poll.c Normal file
View File

@ -0,0 +1,100 @@
/*
* Event loop with file descriptor polling
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include <sys/epoll.h>
#include "hw/dataplane/event-poll.h"
/* Add an event notifier and its callback for polling */
void event_poll_add(EventPoll *poll, EventHandler *handler,
EventNotifier *notifier, EventCallback *callback)
{
struct epoll_event event = {
.events = EPOLLIN,
.data.ptr = handler,
};
handler->notifier = notifier;
handler->callback = callback;
if (epoll_ctl(poll->epoll_fd, EPOLL_CTL_ADD,
event_notifier_get_fd(notifier), &event) != 0) {
fprintf(stderr, "failed to add event handler to epoll: %m\n");
exit(1);
}
}
/* Event callback for stopping event_poll() */
static void handle_stop(EventHandler *handler)
{
/* Do nothing */
}
void event_poll_init(EventPoll *poll)
{
/* Create epoll file descriptor */
poll->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
if (poll->epoll_fd < 0) {
fprintf(stderr, "epoll_create1 failed: %m\n");
exit(1);
}
/* Set up stop notifier */
if (event_notifier_init(&poll->stop_notifier, 0) < 0) {
fprintf(stderr, "failed to init stop notifier\n");
exit(1);
}
event_poll_add(poll, &poll->stop_handler,
&poll->stop_notifier, handle_stop);
}
void event_poll_cleanup(EventPoll *poll)
{
event_notifier_cleanup(&poll->stop_notifier);
close(poll->epoll_fd);
poll->epoll_fd = -1;
}
/* Block until the next event and invoke its callback */
void event_poll(EventPoll *poll)
{
EventHandler *handler;
struct epoll_event event;
int nevents;
/* Wait for the next event. Only do one event per call to keep the
* function simple, this could be changed later. */
do {
nevents = epoll_wait(poll->epoll_fd, &event, 1, -1);
} while (nevents < 0 && errno == EINTR);
if (unlikely(nevents != 1)) {
fprintf(stderr, "epoll_wait failed: %m\n");
exit(1); /* should never happen */
}
/* Find out which event handler has become active */
handler = event.data.ptr;
/* Clear the eventfd */
event_notifier_test_and_clear(handler->notifier);
/* Handle the event */
handler->callback(handler);
}
/* Stop event_poll()
*
* This function can be used from another thread.
*/
void event_poll_notify(EventPoll *poll)
{
event_notifier_set(&poll->stop_notifier);
}

40
hw/dataplane/event-poll.h Normal file
View File

@ -0,0 +1,40 @@
/*
* Event loop with file descriptor polling
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef EVENT_POLL_H
#define EVENT_POLL_H
#include "qemu/event_notifier.h"
typedef struct EventHandler EventHandler;
typedef void EventCallback(EventHandler *handler);
struct EventHandler {
EventNotifier *notifier; /* eventfd */
EventCallback *callback; /* callback function */
};
typedef struct {
int epoll_fd; /* epoll(2) file descriptor */
EventNotifier stop_notifier; /* stop poll notifier */
EventHandler stop_handler; /* stop poll handler */
} EventPoll;
void event_poll_add(EventPoll *poll, EventHandler *handler,
EventNotifier *notifier, EventCallback *callback);
void event_poll_init(EventPoll *poll);
void event_poll_cleanup(EventPoll *poll);
void event_poll(EventPoll *poll);
void event_poll_notify(EventPoll *poll);
#endif /* EVENT_POLL_H */

176
hw/dataplane/hostmem.c Normal file
View File

@ -0,0 +1,176 @@
/*
* Thread-safe guest to host memory mapping
*
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "exec/address-spaces.h"
#include "hostmem.h"
static int hostmem_lookup_cmp(const void *phys_, const void *region_)
{
hwaddr phys = *(const hwaddr *)phys_;
const HostMemRegion *region = region_;
if (phys < region->guest_addr) {
return -1;
} else if (phys >= region->guest_addr + region->size) {
return 1;
} else {
return 0;
}
}
/**
* Map guest physical address to host pointer
*/
void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write)
{
HostMemRegion *region;
void *host_addr = NULL;
hwaddr offset_within_region;
qemu_mutex_lock(&hostmem->current_regions_lock);
region = bsearch(&phys, hostmem->current_regions,
hostmem->num_current_regions,
sizeof(hostmem->current_regions[0]),
hostmem_lookup_cmp);
if (!region) {
goto out;
}
if (is_write && region->readonly) {
goto out;
}
offset_within_region = phys - region->guest_addr;
if (len <= region->size - offset_within_region) {
host_addr = region->host_addr + offset_within_region;
}
out:
qemu_mutex_unlock(&hostmem->current_regions_lock);
return host_addr;
}
/**
* Install new regions list
*/
static void hostmem_listener_commit(MemoryListener *listener)
{
HostMem *hostmem = container_of(listener, HostMem, listener);
qemu_mutex_lock(&hostmem->current_regions_lock);
g_free(hostmem->current_regions);
hostmem->current_regions = hostmem->new_regions;
hostmem->num_current_regions = hostmem->num_new_regions;
qemu_mutex_unlock(&hostmem->current_regions_lock);
/* Reset new regions list */
hostmem->new_regions = NULL;
hostmem->num_new_regions = 0;
}
/**
* Add a MemoryRegionSection to the new regions list
*/
static void hostmem_append_new_region(HostMem *hostmem,
MemoryRegionSection *section)
{
void *ram_ptr = memory_region_get_ram_ptr(section->mr);
size_t num = hostmem->num_new_regions;
size_t new_size = (num + 1) * sizeof(hostmem->new_regions[0]);
hostmem->new_regions = g_realloc(hostmem->new_regions, new_size);
hostmem->new_regions[num] = (HostMemRegion){
.host_addr = ram_ptr + section->offset_within_region,
.guest_addr = section->offset_within_address_space,
.size = section->size,
.readonly = section->readonly,
};
hostmem->num_new_regions++;
}
static void hostmem_listener_append_region(MemoryListener *listener,
MemoryRegionSection *section)
{
HostMem *hostmem = container_of(listener, HostMem, listener);
/* Ignore non-RAM regions, we may not be able to map them */
if (!memory_region_is_ram(section->mr)) {
return;
}
/* Ignore regions with dirty logging, we cannot mark them dirty */
if (memory_region_is_logging(section->mr)) {
return;
}
hostmem_append_new_region(hostmem, section);
}
/* We don't implement most MemoryListener callbacks, use these nop stubs */
static void hostmem_listener_dummy(MemoryListener *listener)
{
}
static void hostmem_listener_section_dummy(MemoryListener *listener,
MemoryRegionSection *section)
{
}
static void hostmem_listener_eventfd_dummy(MemoryListener *listener,
MemoryRegionSection *section,
bool match_data, uint64_t data,
EventNotifier *e)
{
}
static void hostmem_listener_coalesced_mmio_dummy(MemoryListener *listener,
MemoryRegionSection *section,
hwaddr addr, hwaddr len)
{
}
void hostmem_init(HostMem *hostmem)
{
memset(hostmem, 0, sizeof(*hostmem));
qemu_mutex_init(&hostmem->current_regions_lock);
hostmem->listener = (MemoryListener){
.begin = hostmem_listener_dummy,
.commit = hostmem_listener_commit,
.region_add = hostmem_listener_append_region,
.region_del = hostmem_listener_section_dummy,
.region_nop = hostmem_listener_append_region,
.log_start = hostmem_listener_section_dummy,
.log_stop = hostmem_listener_section_dummy,
.log_sync = hostmem_listener_section_dummy,
.log_global_start = hostmem_listener_dummy,
.log_global_stop = hostmem_listener_dummy,
.eventfd_add = hostmem_listener_eventfd_dummy,
.eventfd_del = hostmem_listener_eventfd_dummy,
.coalesced_mmio_add = hostmem_listener_coalesced_mmio_dummy,
.coalesced_mmio_del = hostmem_listener_coalesced_mmio_dummy,
.priority = 10,
};
memory_listener_register(&hostmem->listener, &address_space_memory);
if (hostmem->num_new_regions > 0) {
hostmem_listener_commit(&hostmem->listener);
}
}
void hostmem_finalize(HostMem *hostmem)
{
memory_listener_unregister(&hostmem->listener);
g_free(hostmem->new_regions);
g_free(hostmem->current_regions);
qemu_mutex_destroy(&hostmem->current_regions_lock);
}

57
hw/dataplane/hostmem.h Normal file
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@ -0,0 +1,57 @@
/*
* Thread-safe guest to host memory mapping
*
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef HOSTMEM_H
#define HOSTMEM_H
#include "exec/memory.h"
#include "qemu/thread.h"
typedef struct {
void *host_addr;
hwaddr guest_addr;
uint64_t size;
bool readonly;
} HostMemRegion;
typedef struct {
/* The listener is invoked when regions change and a new list of regions is
* built up completely before they are installed.
*/
MemoryListener listener;
HostMemRegion *new_regions;
size_t num_new_regions;
/* Current regions are accessed from multiple threads either to lookup
* addresses or to install a new list of regions. The lock protects the
* pointer and the regions.
*/
QemuMutex current_regions_lock;
HostMemRegion *current_regions;
size_t num_current_regions;
} HostMem;
void hostmem_init(HostMem *hostmem);
void hostmem_finalize(HostMem *hostmem);
/**
* Map a guest physical address to a pointer
*
* Note that there is map/unmap mechanism here. The caller must ensure that
* mapped memory is no longer used across events like hot memory unplug. This
* can be done with other mechanisms like bdrv_drain_all() that quiesce
* in-flight I/O.
*/
void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write);
#endif /* HOSTMEM_H */

117
hw/dataplane/ioq.c Normal file
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@ -0,0 +1,117 @@
/*
* Linux AIO request queue
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "hw/dataplane/ioq.h"
void ioq_init(IOQueue *ioq, int fd, unsigned int max_reqs)
{
int rc;
ioq->fd = fd;
ioq->max_reqs = max_reqs;
memset(&ioq->io_ctx, 0, sizeof ioq->io_ctx);
rc = io_setup(max_reqs, &ioq->io_ctx);
if (rc != 0) {
fprintf(stderr, "ioq io_setup failed %d\n", rc);
exit(1);
}
rc = event_notifier_init(&ioq->io_notifier, 0);
if (rc != 0) {
fprintf(stderr, "ioq io event notifier creation failed %d\n", rc);
exit(1);
}
ioq->freelist = g_malloc0(sizeof ioq->freelist[0] * max_reqs);
ioq->freelist_idx = 0;
ioq->queue = g_malloc0(sizeof ioq->queue[0] * max_reqs);
ioq->queue_idx = 0;
}
void ioq_cleanup(IOQueue *ioq)
{
g_free(ioq->freelist);
g_free(ioq->queue);
event_notifier_cleanup(&ioq->io_notifier);
io_destroy(ioq->io_ctx);
}
EventNotifier *ioq_get_notifier(IOQueue *ioq)
{
return &ioq->io_notifier;
}
struct iocb *ioq_get_iocb(IOQueue *ioq)
{
/* Underflow cannot happen since ioq is sized for max_reqs */
assert(ioq->freelist_idx != 0);
struct iocb *iocb = ioq->freelist[--ioq->freelist_idx];
ioq->queue[ioq->queue_idx++] = iocb;
return iocb;
}
void ioq_put_iocb(IOQueue *ioq, struct iocb *iocb)
{
/* Overflow cannot happen since ioq is sized for max_reqs */
assert(ioq->freelist_idx != ioq->max_reqs);
ioq->freelist[ioq->freelist_idx++] = iocb;
}
struct iocb *ioq_rdwr(IOQueue *ioq, bool read, struct iovec *iov,
unsigned int count, long long offset)
{
struct iocb *iocb = ioq_get_iocb(ioq);
if (read) {
io_prep_preadv(iocb, ioq->fd, iov, count, offset);
} else {
io_prep_pwritev(iocb, ioq->fd, iov, count, offset);
}
io_set_eventfd(iocb, event_notifier_get_fd(&ioq->io_notifier));
return iocb;
}
int ioq_submit(IOQueue *ioq)
{
int rc = io_submit(ioq->io_ctx, ioq->queue_idx, ioq->queue);
ioq->queue_idx = 0; /* reset */
return rc;
}
int ioq_run_completion(IOQueue *ioq, IOQueueCompletion *completion,
void *opaque)
{
struct io_event events[ioq->max_reqs];
int nevents, i;
do {
nevents = io_getevents(ioq->io_ctx, 0, ioq->max_reqs, events, NULL);
} while (nevents < 0 && errno == EINTR);
if (nevents < 0) {
return nevents;
}
for (i = 0; i < nevents; i++) {
ssize_t ret = ((uint64_t)events[i].res2 << 32) | events[i].res;
completion(events[i].obj, ret, opaque);
ioq_put_iocb(ioq, events[i].obj);
}
return nevents;
}

57
hw/dataplane/ioq.h Normal file
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@ -0,0 +1,57 @@
/*
* Linux AIO request queue
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef IOQ_H
#define IOQ_H
#include <libaio.h>
#include "qemu/event_notifier.h"
typedef struct {
int fd; /* file descriptor */
unsigned int max_reqs; /* max length of freelist and queue */
io_context_t io_ctx; /* Linux AIO context */
EventNotifier io_notifier; /* Linux AIO eventfd */
/* Requests can complete in any order so a free list is necessary to manage
* available iocbs.
*/
struct iocb **freelist; /* free iocbs */
unsigned int freelist_idx;
/* Multiple requests are queued up before submitting them all in one go */
struct iocb **queue; /* queued iocbs */
unsigned int queue_idx;
} IOQueue;
void ioq_init(IOQueue *ioq, int fd, unsigned int max_reqs);
void ioq_cleanup(IOQueue *ioq);
EventNotifier *ioq_get_notifier(IOQueue *ioq);
struct iocb *ioq_get_iocb(IOQueue *ioq);
void ioq_put_iocb(IOQueue *ioq, struct iocb *iocb);
struct iocb *ioq_rdwr(IOQueue *ioq, bool read, struct iovec *iov,
unsigned int count, long long offset);
int ioq_submit(IOQueue *ioq);
static inline unsigned int ioq_num_queued(IOQueue *ioq)
{
return ioq->queue_idx;
}
typedef void IOQueueCompletion(struct iocb *iocb, ssize_t ret, void *opaque);
int ioq_run_completion(IOQueue *ioq, IOQueueCompletion *completion,
void *opaque);
#endif /* IOQ_H */

465
hw/dataplane/virtio-blk.c Normal file
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@ -0,0 +1,465 @@
/*
* Dedicated thread for virtio-blk I/O processing
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "trace.h"
#include "qemu/iov.h"
#include "event-poll.h"
#include "qemu/thread.h"
#include "vring.h"
#include "ioq.h"
#include "migration/migration.h"
#include "hw/virtio-blk.h"
#include "hw/dataplane/virtio-blk.h"
enum {
SEG_MAX = 126, /* maximum number of I/O segments */
VRING_MAX = SEG_MAX + 2, /* maximum number of vring descriptors */
REQ_MAX = VRING_MAX, /* maximum number of requests in the vring,
* is VRING_MAX / 2 with traditional and
* VRING_MAX with indirect descriptors */
};
typedef struct {
struct iocb iocb; /* Linux AIO control block */
QEMUIOVector *inhdr; /* iovecs for virtio_blk_inhdr */
unsigned int head; /* vring descriptor index */
} VirtIOBlockRequest;
struct VirtIOBlockDataPlane {
bool started;
QEMUBH *start_bh;
QemuThread thread;
VirtIOBlkConf *blk;
int fd; /* image file descriptor */
VirtIODevice *vdev;
Vring vring; /* virtqueue vring */
EventNotifier *guest_notifier; /* irq */
EventPoll event_poll; /* event poller */
EventHandler io_handler; /* Linux AIO completion handler */
EventHandler notify_handler; /* virtqueue notify handler */
IOQueue ioqueue; /* Linux AIO queue (should really be per
dataplane thread) */
VirtIOBlockRequest requests[REQ_MAX]; /* pool of requests, managed by the
queue */
unsigned int num_reqs;
Error *migration_blocker;
};
/* Raise an interrupt to signal guest, if necessary */
static void notify_guest(VirtIOBlockDataPlane *s)
{
if (!vring_should_notify(s->vdev, &s->vring)) {
return;
}
event_notifier_set(s->guest_notifier);
}
static void complete_request(struct iocb *iocb, ssize_t ret, void *opaque)
{
VirtIOBlockDataPlane *s = opaque;
VirtIOBlockRequest *req = container_of(iocb, VirtIOBlockRequest, iocb);
struct virtio_blk_inhdr hdr;
int len;
if (likely(ret >= 0)) {
hdr.status = VIRTIO_BLK_S_OK;
len = ret;
} else {
hdr.status = VIRTIO_BLK_S_IOERR;
len = 0;
}
trace_virtio_blk_data_plane_complete_request(s, req->head, ret);
qemu_iovec_from_buf(req->inhdr, 0, &hdr, sizeof(hdr));
qemu_iovec_destroy(req->inhdr);
g_slice_free(QEMUIOVector, req->inhdr);
/* According to the virtio specification len should be the number of bytes
* written to, but for virtio-blk it seems to be the number of bytes
* transferred plus the status bytes.
*/
vring_push(&s->vring, req->head, len + sizeof(hdr));
s->num_reqs--;
}
static void complete_request_early(VirtIOBlockDataPlane *s, unsigned int head,
QEMUIOVector *inhdr, unsigned char status)
{
struct virtio_blk_inhdr hdr = {
.status = status,
};
qemu_iovec_from_buf(inhdr, 0, &hdr, sizeof(hdr));
qemu_iovec_destroy(inhdr);
g_slice_free(QEMUIOVector, inhdr);
vring_push(&s->vring, head, sizeof(hdr));
notify_guest(s);
}
/* Get disk serial number */
static void do_get_id_cmd(VirtIOBlockDataPlane *s,
struct iovec *iov, unsigned int iov_cnt,
unsigned int head, QEMUIOVector *inhdr)
{
char id[VIRTIO_BLK_ID_BYTES];
/* Serial number not NUL-terminated when shorter than buffer */
strncpy(id, s->blk->serial ? s->blk->serial : "", sizeof(id));
iov_from_buf(iov, iov_cnt, 0, id, sizeof(id));
complete_request_early(s, head, inhdr, VIRTIO_BLK_S_OK);
}
static int process_request(IOQueue *ioq, struct iovec iov[],
unsigned int out_num, unsigned int in_num,
unsigned int head)
{
VirtIOBlockDataPlane *s = container_of(ioq, VirtIOBlockDataPlane, ioqueue);
struct iovec *in_iov = &iov[out_num];
struct virtio_blk_outhdr outhdr;
QEMUIOVector *inhdr;
size_t in_size;
struct iocb *iocb;
/* Copy in outhdr */
if (unlikely(iov_to_buf(iov, out_num, 0, &outhdr,
sizeof(outhdr)) != sizeof(outhdr))) {
error_report("virtio-blk request outhdr too short");
return -EFAULT;
}
iov_discard_front(&iov, &out_num, sizeof(outhdr));
/* Grab inhdr for later */
in_size = iov_size(in_iov, in_num);
if (in_size < sizeof(struct virtio_blk_inhdr)) {
error_report("virtio_blk request inhdr too short");
return -EFAULT;
}
inhdr = g_slice_new(QEMUIOVector);
qemu_iovec_init(inhdr, 1);
qemu_iovec_concat_iov(inhdr, in_iov, in_num,
in_size - sizeof(struct virtio_blk_inhdr),
sizeof(struct virtio_blk_inhdr));
iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr));
/* TODO Linux sets the barrier bit even when not advertised! */
outhdr.type &= ~VIRTIO_BLK_T_BARRIER;
switch (outhdr.type) {
case VIRTIO_BLK_T_IN:
iocb = ioq_rdwr(ioq, true, in_iov, in_num, outhdr.sector * 512);
break;
case VIRTIO_BLK_T_OUT:
iocb = ioq_rdwr(ioq, false, iov, out_num, outhdr.sector * 512);
break;
case VIRTIO_BLK_T_SCSI_CMD:
/* TODO support SCSI commands */
complete_request_early(s, head, inhdr, VIRTIO_BLK_S_UNSUPP);
return 0;
case VIRTIO_BLK_T_FLUSH:
/* TODO fdsync not supported by Linux AIO, do it synchronously here! */
if (qemu_fdatasync(s->fd) < 0) {
complete_request_early(s, head, inhdr, VIRTIO_BLK_S_IOERR);
} else {
complete_request_early(s, head, inhdr, VIRTIO_BLK_S_OK);
}
return 0;
case VIRTIO_BLK_T_GET_ID:
do_get_id_cmd(s, in_iov, in_num, head, inhdr);
return 0;
default:
error_report("virtio-blk unsupported request type %#x", outhdr.type);
qemu_iovec_destroy(inhdr);
g_slice_free(QEMUIOVector, inhdr);
return -EFAULT;
}
/* Fill in virtio block metadata needed for completion */
VirtIOBlockRequest *req = container_of(iocb, VirtIOBlockRequest, iocb);
req->head = head;
req->inhdr = inhdr;
return 0;
}
static void handle_notify(EventHandler *handler)
{
VirtIOBlockDataPlane *s = container_of(handler, VirtIOBlockDataPlane,
notify_handler);
/* There is one array of iovecs into which all new requests are extracted
* from the vring. Requests are read from the vring and the translated
* descriptors are written to the iovecs array. The iovecs do not have to
* persist across handle_notify() calls because the kernel copies the
* iovecs on io_submit().
*
* Handling io_submit() EAGAIN may require storing the requests across
* handle_notify() calls until the kernel has sufficient resources to
* accept more I/O. This is not implemented yet.
*/
struct iovec iovec[VRING_MAX];
struct iovec *end = &iovec[VRING_MAX];
struct iovec *iov = iovec;
/* When a request is read from the vring, the index of the first descriptor
* (aka head) is returned so that the completed request can be pushed onto
* the vring later.
*
* The number of hypervisor read-only iovecs is out_num. The number of
* hypervisor write-only iovecs is in_num.
*/
int head;
unsigned int out_num = 0, in_num = 0;
unsigned int num_queued;
for (;;) {
/* Disable guest->host notifies to avoid unnecessary vmexits */
vring_disable_notification(s->vdev, &s->vring);
for (;;) {
head = vring_pop(s->vdev, &s->vring, iov, end, &out_num, &in_num);
if (head < 0) {
break; /* no more requests */
}
trace_virtio_blk_data_plane_process_request(s, out_num, in_num,
head);
if (process_request(&s->ioqueue, iov, out_num, in_num, head) < 0) {
vring_set_broken(&s->vring);
break;
}
iov += out_num + in_num;
}
if (likely(head == -EAGAIN)) { /* vring emptied */
/* Re-enable guest->host notifies and stop processing the vring.
* But if the guest has snuck in more descriptors, keep processing.
*/
if (vring_enable_notification(s->vdev, &s->vring)) {
break;
}
} else { /* head == -ENOBUFS or fatal error, iovecs[] is depleted */
/* Since there are no iovecs[] left, stop processing for now. Do
* not re-enable guest->host notifies since the I/O completion
* handler knows to check for more vring descriptors anyway.
*/
break;
}
}
num_queued = ioq_num_queued(&s->ioqueue);
if (num_queued > 0) {
s->num_reqs += num_queued;
int rc = ioq_submit(&s->ioqueue);
if (unlikely(rc < 0)) {
fprintf(stderr, "ioq_submit failed %d\n", rc);
exit(1);
}
}
}
static void handle_io(EventHandler *handler)
{
VirtIOBlockDataPlane *s = container_of(handler, VirtIOBlockDataPlane,
io_handler);
if (ioq_run_completion(&s->ioqueue, complete_request, s) > 0) {
notify_guest(s);
}
/* If there were more requests than iovecs, the vring will not be empty yet
* so check again. There should now be enough resources to process more
* requests.
*/
if (unlikely(vring_more_avail(&s->vring))) {
handle_notify(&s->notify_handler);
}
}
static void *data_plane_thread(void *opaque)
{
VirtIOBlockDataPlane *s = opaque;
do {
event_poll(&s->event_poll);
} while (s->started || s->num_reqs > 0);
return NULL;
}
static void start_data_plane_bh(void *opaque)
{
VirtIOBlockDataPlane *s = opaque;
qemu_bh_delete(s->start_bh);
s->start_bh = NULL;
qemu_thread_create(&s->thread, data_plane_thread,
s, QEMU_THREAD_JOINABLE);
}
bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
VirtIOBlockDataPlane **dataplane)
{
VirtIOBlockDataPlane *s;
int fd;
*dataplane = NULL;
if (!blk->data_plane) {
return true;
}
if (blk->scsi) {
error_report("device is incompatible with x-data-plane, use scsi=off");
return false;
}
if (blk->config_wce) {
error_report("device is incompatible with x-data-plane, "
"use config-wce=off");
return false;
}
fd = raw_get_aio_fd(blk->conf.bs);
if (fd < 0) {
error_report("drive is incompatible with x-data-plane, "
"use format=raw,cache=none,aio=native");
return false;
}
s = g_new0(VirtIOBlockDataPlane, 1);
s->vdev = vdev;
s->fd = fd;
s->blk = blk;
/* Prevent block operations that conflict with data plane thread */
bdrv_set_in_use(blk->conf.bs, 1);
error_setg(&s->migration_blocker,
"x-data-plane does not support migration");
migrate_add_blocker(s->migration_blocker);
*dataplane = s;
return true;
}
void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
{
if (!s) {
return;
}
virtio_blk_data_plane_stop(s);
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
bdrv_set_in_use(s->blk->conf.bs, 0);
g_free(s);
}
void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
{
VirtQueue *vq;
int i;
if (s->started) {
return;
}
vq = virtio_get_queue(s->vdev, 0);
if (!vring_setup(&s->vring, s->vdev, 0)) {
return;
}
event_poll_init(&s->event_poll);
/* Set up guest notifier (irq) */
if (s->vdev->binding->set_guest_notifiers(s->vdev->binding_opaque,
true) != 0) {
fprintf(stderr, "virtio-blk failed to set guest notifier, "
"ensure -enable-kvm is set\n");
exit(1);
}
s->guest_notifier = virtio_queue_get_guest_notifier(vq);
/* Set up virtqueue notify */
if (s->vdev->binding->set_host_notifier(s->vdev->binding_opaque,
0, true) != 0) {
fprintf(stderr, "virtio-blk failed to set host notifier\n");
exit(1);
}
event_poll_add(&s->event_poll, &s->notify_handler,
virtio_queue_get_host_notifier(vq),
handle_notify);
/* Set up ioqueue */
ioq_init(&s->ioqueue, s->fd, REQ_MAX);
for (i = 0; i < ARRAY_SIZE(s->requests); i++) {
ioq_put_iocb(&s->ioqueue, &s->requests[i].iocb);
}
event_poll_add(&s->event_poll, &s->io_handler,
ioq_get_notifier(&s->ioqueue), handle_io);
s->started = true;
trace_virtio_blk_data_plane_start(s);
/* Kick right away to begin processing requests already in vring */
event_notifier_set(virtio_queue_get_host_notifier(vq));
/* Spawn thread in BH so it inherits iothread cpusets */
s->start_bh = qemu_bh_new(start_data_plane_bh, s);
qemu_bh_schedule(s->start_bh);
}
void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
{
if (!s->started) {
return;
}
s->started = false;
trace_virtio_blk_data_plane_stop(s);
/* Stop thread or cancel pending thread creation BH */
if (s->start_bh) {
qemu_bh_delete(s->start_bh);
s->start_bh = NULL;
} else {
event_poll_notify(&s->event_poll);
qemu_thread_join(&s->thread);
}
ioq_cleanup(&s->ioqueue);
s->vdev->binding->set_host_notifier(s->vdev->binding_opaque, 0, false);
event_poll_cleanup(&s->event_poll);
/* Clean up guest notifier (irq) */
s->vdev->binding->set_guest_notifiers(s->vdev->binding_opaque, false);
vring_teardown(&s->vring);
}

29
hw/dataplane/virtio-blk.h Normal file
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/*
* Dedicated thread for virtio-blk I/O processing
*
* Copyright 2012 IBM, Corp.
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef HW_DATAPLANE_VIRTIO_BLK_H
#define HW_DATAPLANE_VIRTIO_BLK_H
#include "hw/virtio.h"
typedef struct VirtIOBlockDataPlane VirtIOBlockDataPlane;
bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
VirtIOBlockDataPlane **dataplane);
void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s);
void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s);
void virtio_blk_data_plane_drain(VirtIOBlockDataPlane *s);
#endif /* HW_DATAPLANE_VIRTIO_BLK_H */

362
hw/dataplane/vring.c Normal file
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/* 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 "hw/dataplane/vring.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;
}
}

62
hw/dataplane/vring.h Normal file
View File

@ -0,0 +1,62 @@
/* 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 <linux/virtio_ring.h>
#include "qemu-common.h"
#include "hw/dataplane/hostmem.h"
#include "hw/virtio.h"
typedef struct {
HostMem hostmem; /* guest memory mapper */
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;
static inline unsigned int vring_get_num(Vring *vring)
{
return vring->vr.num;
}
/* Are there more descriptors available? */
static inline bool vring_more_avail(Vring *vring)
{
return vring->vr.avail->idx != vring->last_avail_idx;
}
/* 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);
void vring_disable_notification(VirtIODevice *vdev, Vring *vring);
bool vring_enable_notification(VirtIODevice *vdev, Vring *vring);
bool vring_should_notify(VirtIODevice *vdev, Vring *vring);
int vring_pop(VirtIODevice *vdev, Vring *vring,
struct iovec iov[], struct iovec *iov_end,
unsigned int *out_num, unsigned int *in_num);
void vring_push(Vring *vring, unsigned int head, int len);
#endif /* VRING_H */

53
hw/virtio-blk.c
View File

@ -17,6 +17,9 @@
#include "hw/block-common.h"
#include "sysemu/blockdev.h"
#include "virtio-blk.h"
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
#include "hw/dataplane/virtio-blk.h"
#endif
#include "scsi-defs.h"
#ifdef __linux__
# include <scsi/sg.h>
@ -33,6 +36,9 @@ typedef struct VirtIOBlock
VirtIOBlkConf *blk;
unsigned short sector_mask;
DeviceState *qdev;
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
VirtIOBlockDataPlane *dataplane;
#endif
} VirtIOBlock;
static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
@ -392,10 +398,14 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req,
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
req->elem.out_num - 1);
virtio_blk_handle_write(req, mrb);
} else {
} else if (type == VIRTIO_BLK_T_IN || type == VIRTIO_BLK_T_BARRIER) {
/* VIRTIO_BLK_T_IN is 0, so we can't just & it. */
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
req->elem.in_num - 1);
virtio_blk_handle_read(req);
} else {
virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
g_free(req);
}
}
@ -407,6 +417,16 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
.num_writes = 0,
};
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* dataplane here instead of waiting for .set_status().
*/
if (s->dataplane) {
virtio_blk_data_plane_start(s->dataplane);
return;
}
#endif
while ((req = virtio_blk_get_request(s))) {
virtio_blk_handle_request(req, &mrb);
}
@ -446,8 +466,9 @@ static void virtio_blk_dma_restart_cb(void *opaque, int running,
{
VirtIOBlock *s = opaque;
if (!running)
if (!running) {
return;
}
if (!s->bh) {
s->bh = qemu_bh_new(virtio_blk_dma_restart_bh, s);
@ -457,6 +478,14 @@ static void virtio_blk_dma_restart_cb(void *opaque, int running,
static void virtio_blk_reset(VirtIODevice *vdev)
{
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
VirtIOBlock *s = to_virtio_blk(vdev);
if (s->dataplane) {
virtio_blk_data_plane_stop(s->dataplane);
}
#endif
/*
* This should cancel pending requests, but can't do nicely until there
* are per-device request lists.
@ -524,6 +553,9 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
features |= (1 << VIRTIO_BLK_F_BLK_SIZE);
features |= (1 << VIRTIO_BLK_F_SCSI);
if (s->blk->config_wce) {
features |= (1 << VIRTIO_BLK_F_CONFIG_WCE);
}
if (bdrv_enable_write_cache(s->bs))
features |= (1 << VIRTIO_BLK_F_WCE);
@ -538,6 +570,12 @@ static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
VirtIOBlock *s = to_virtio_blk(vdev);
uint32_t features;
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
if (s->dataplane && !(status & VIRTIO_CONFIG_S_DRIVER)) {
virtio_blk_data_plane_stop(s->dataplane);
}
#endif
if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return;
}
@ -635,6 +673,12 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1;
s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
if (!virtio_blk_data_plane_create(&s->vdev, blk, &s->dataplane)) {
virtio_cleanup(&s->vdev);
return NULL;
}
#endif
qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
s->qdev = dev;
@ -652,6 +696,11 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
void virtio_blk_exit(VirtIODevice *vdev)
{
VirtIOBlock *s = to_virtio_blk(vdev);
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
virtio_blk_data_plane_destroy(s->dataplane);
s->dataplane = NULL;
#endif
unregister_savevm(s->qdev, "virtio-blk", s);
blockdev_mark_auto_del(s->bs);
virtio_cleanup(vdev);

5
hw/virtio-blk.h
View File

@ -104,10 +104,11 @@ struct VirtIOBlkConf
BlockConf conf;
char *serial;
uint32_t scsi;
uint32_t config_wce;
uint32_t data_plane;
};
#define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \
DEFINE_VIRTIO_COMMON_FEATURES(_state, _field), \
DEFINE_PROP_BIT("config-wce", _state, _field, VIRTIO_BLK_F_CONFIG_WCE, true)
DEFINE_VIRTIO_COMMON_FEATURES(_state, _field)
#endif

4
hw/virtio-pci.c
View File

@ -936,7 +936,11 @@ static Property virtio_blk_properties[] = {
#ifdef __linux__
DEFINE_PROP_BIT("scsi", VirtIOPCIProxy, blk.scsi, 0, true),
#endif
DEFINE_PROP_BIT("config-wce", VirtIOPCIProxy, blk.config_wce, 0, true),
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags, VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
DEFINE_PROP_BIT("x-data-plane", VirtIOPCIProxy, blk.data_plane, 0, false),
#endif
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
DEFINE_VIRTIO_BLK_FEATURES(VirtIOPCIProxy, host_features),
DEFINE_PROP_END_OF_LIST(),

9
include/block/block.h
View File

@ -365,6 +365,15 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs);
void bdrv_set_in_use(BlockDriverState *bs, int in_use);
int bdrv_in_use(BlockDriverState *bs);
#ifdef CONFIG_LINUX_AIO
int raw_get_aio_fd(BlockDriverState *bs);
#else
static inline int raw_get_aio_fd(BlockDriverState *bs)
{
return -ENOTSUP;
}
#endif
enum BlockAcctType {
BDRV_ACCT_READ,
BDRV_ACCT_WRITE,

3
include/qemu-common.h
View File

@ -329,6 +329,9 @@ void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov);
void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len);
void qemu_iovec_concat(QEMUIOVector *dst,
QEMUIOVector *src, size_t soffset, size_t sbytes);
void qemu_iovec_concat_iov(QEMUIOVector *dst,
struct iovec *src_iov, unsigned int src_cnt,
size_t soffset, size_t sbytes);
void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,

13
include/qemu/iov.h
View File

@ -99,4 +99,17 @@ unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt,
const struct iovec *iov, unsigned int iov_cnt,
size_t offset, size_t bytes);
/*
* Remove a given number of bytes from the front or back of a vector.
* This may update iov and/or iov_cnt to exclude iovec elements that are
* no longer required.
*
* The number of bytes actually discarded is returned. This number may be
* smaller than requested if the vector is too small.
*/
size_t iov_discard_front(struct iovec **iov, unsigned int *iov_cnt,
size_t bytes);
size_t iov_discard_back(struct iovec *iov, unsigned int *iov_cnt,
size_t bytes);
#endif

98
iov.c
View File

@ -288,6 +288,36 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
++qiov->niov;
}
/*
* Concatenates (partial) iovecs from src_iov to the end of dst.
* It starts copying after skipping `soffset' bytes at the
* beginning of src and adds individual vectors from src to
* dst copies up to `sbytes' bytes total, or up to the end
* of src_iov if it comes first. This way, it is okay to specify
* very large value for `sbytes' to indicate "up to the end
* of src".
* Only vector pointers are processed, not the actual data buffers.
*/
void qemu_iovec_concat_iov(QEMUIOVector *dst,
struct iovec *src_iov, unsigned int src_cnt,
size_t soffset, size_t sbytes)
{
int i;
size_t done;
assert(dst->nalloc != -1);
for (i = 0, done = 0; done < sbytes && i < src_cnt; i++) {
if (soffset < src_iov[i].iov_len) {
size_t len = MIN(src_iov[i].iov_len - soffset, sbytes - done);
qemu_iovec_add(dst, src_iov[i].iov_base + soffset, len);
done += len;
soffset = 0;
} else {
soffset -= src_iov[i].iov_len;
}
}
assert(soffset == 0); /* offset beyond end of src */
}
/*
* Concatenates (partial) iovecs from src to the end of dst.
* It starts copying after skipping `soffset' bytes at the
@ -301,22 +331,7 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
void qemu_iovec_concat(QEMUIOVector *dst,
QEMUIOVector *src, size_t soffset, size_t sbytes)
{
int i;
size_t done;
struct iovec *siov = src->iov;
assert(dst->nalloc != -1);
assert(src->size >= soffset);
for (i = 0, done = 0; done < sbytes && i < src->niov; i++) {
if (soffset < siov[i].iov_len) {
size_t len = MIN(siov[i].iov_len - soffset, sbytes - done);
qemu_iovec_add(dst, siov[i].iov_base + soffset, len);
done += len;
soffset = 0;
} else {
soffset -= siov[i].iov_len;
}
}
/* return done; */
qemu_iovec_concat_iov(dst, src->iov, src->niov, soffset, sbytes);
}
void qemu_iovec_destroy(QEMUIOVector *qiov)
@ -354,3 +369,54 @@ size_t qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
{
return iov_memset(qiov->iov, qiov->niov, offset, fillc, bytes);
}
size_t iov_discard_front(struct iovec **iov, unsigned int *iov_cnt,
size_t bytes)
{
size_t total = 0;
struct iovec *cur;
for (cur = *iov; *iov_cnt > 0; cur++) {
if (cur->iov_len > bytes) {
cur->iov_base += bytes;
cur->iov_len -= bytes;
total += bytes;
break;
}
bytes -= cur->iov_len;
total += cur->iov_len;
*iov_cnt -= 1;
}
*iov = cur;
return total;
}
size_t iov_discard_back(struct iovec *iov, unsigned int *iov_cnt,
size_t bytes)
{
size_t total = 0;
struct iovec *cur;
if (*iov_cnt == 0) {
return 0;
}
cur = iov + (*iov_cnt - 1);
while (*iov_cnt > 0) {
if (cur->iov_len > bytes) {
cur->iov_len -= bytes;
total += bytes;
break;
}
bytes -= cur->iov_len;
total += cur->iov_len;
cur--;
*iov_cnt -= 1;
}
return total;
}

10
qemu-img.c
View File

@ -348,9 +348,13 @@ static int img_create(int argc, char **argv)
char *end;
sval = strtosz_suffix(argv[optind++], &end, STRTOSZ_DEFSUFFIX_B);
if (sval < 0 || *end) {
error_report("Invalid image size specified! You may use k, M, G or "
"T suffixes for ");
error_report("kilobytes, megabytes, gigabytes and terabytes.");
if (sval == -ERANGE) {
error_report("Image size must be less than 8 EiB!");
} else {
error_report("Invalid image size specified! You may use k, M, "
"G or T suffixes for ");
error_report("kilobytes, megabytes, gigabytes and terabytes.");
}
return 1;
}
img_size = (uint64_t)sval;

150
tests/test-iov.c
View File

@ -250,11 +250,161 @@ static void test_io(void)
#endif
}
static void test_discard_front(void)
{
struct iovec *iov;
struct iovec *iov_tmp;
unsigned int iov_cnt;
unsigned int iov_cnt_tmp;
void *old_base;
size_t size;
size_t ret;
/* Discard zero bytes */
iov_random(&iov, &iov_cnt);
iov_tmp = iov;
iov_cnt_tmp = iov_cnt;
ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, 0);
g_assert(ret == 0);
g_assert(iov_tmp == iov);
g_assert(iov_cnt_tmp == iov_cnt);
iov_free(iov, iov_cnt);
/* Discard more bytes than vector size */
iov_random(&iov, &iov_cnt);
iov_tmp = iov;
iov_cnt_tmp = iov_cnt;
size = iov_size(iov, iov_cnt);
ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size + 1);
g_assert(ret == size);
g_assert(iov_cnt_tmp == 0);
iov_free(iov, iov_cnt);
/* Discard entire vector */
iov_random(&iov, &iov_cnt);
iov_tmp = iov;
iov_cnt_tmp = iov_cnt;
size = iov_size(iov, iov_cnt);
ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_cnt_tmp == 0);
iov_free(iov, iov_cnt);
/* Discard within first element */
iov_random(&iov, &iov_cnt);
iov_tmp = iov;
iov_cnt_tmp = iov_cnt;
old_base = iov->iov_base;
size = g_test_rand_int_range(1, iov->iov_len);
ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_tmp == iov);
g_assert(iov_cnt_tmp == iov_cnt);
g_assert(iov_tmp->iov_base == old_base + size);
iov_tmp->iov_base = old_base; /* undo before g_free() */
iov_free(iov, iov_cnt);
/* Discard entire first element */
iov_random(&iov, &iov_cnt);
iov_tmp = iov;
iov_cnt_tmp = iov_cnt;
ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, iov->iov_len);
g_assert(ret == iov->iov_len);
g_assert(iov_tmp == iov + 1);
g_assert(iov_cnt_tmp == iov_cnt - 1);
iov_free(iov, iov_cnt);
/* Discard within second element */
iov_random(&iov, &iov_cnt);
iov_tmp = iov;
iov_cnt_tmp = iov_cnt;
old_base = iov[1].iov_base;
size = iov->iov_len + g_test_rand_int_range(1, iov[1].iov_len);
ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_tmp == iov + 1);
g_assert(iov_cnt_tmp == iov_cnt - 1);
g_assert(iov_tmp->iov_base == old_base + (size - iov->iov_len));
iov_tmp->iov_base = old_base; /* undo before g_free() */
iov_free(iov, iov_cnt);
}
static void test_discard_back(void)
{
struct iovec *iov;
unsigned int iov_cnt;
unsigned int iov_cnt_tmp;
void *old_base;
size_t size;
size_t ret;
/* Discard zero bytes */
iov_random(&iov, &iov_cnt);
iov_cnt_tmp = iov_cnt;
ret = iov_discard_back(iov, &iov_cnt_tmp, 0);
g_assert(ret == 0);
g_assert(iov_cnt_tmp == iov_cnt);
iov_free(iov, iov_cnt);
/* Discard more bytes than vector size */
iov_random(&iov, &iov_cnt);
iov_cnt_tmp = iov_cnt;
size = iov_size(iov, iov_cnt);
ret = iov_discard_back(iov, &iov_cnt_tmp, size + 1);
g_assert(ret == size);
g_assert(iov_cnt_tmp == 0);
iov_free(iov, iov_cnt);
/* Discard entire vector */
iov_random(&iov, &iov_cnt);
iov_cnt_tmp = iov_cnt;
size = iov_size(iov, iov_cnt);
ret = iov_discard_back(iov, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_cnt_tmp == 0);
iov_free(iov, iov_cnt);
/* Discard within last element */
iov_random(&iov, &iov_cnt);
iov_cnt_tmp = iov_cnt;
old_base = iov[iov_cnt - 1].iov_base;
size = g_test_rand_int_range(1, iov[iov_cnt - 1].iov_len);
ret = iov_discard_back(iov, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_cnt_tmp == iov_cnt);
g_assert(iov[iov_cnt - 1].iov_base == old_base);
iov_free(iov, iov_cnt);
/* Discard entire last element */
iov_random(&iov, &iov_cnt);
iov_cnt_tmp = iov_cnt;
old_base = iov[iov_cnt - 1].iov_base;
size = iov[iov_cnt - 1].iov_len;
ret = iov_discard_back(iov, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_cnt_tmp == iov_cnt - 1);
iov_free(iov, iov_cnt);
/* Discard within second-to-last element */
iov_random(&iov, &iov_cnt);
iov_cnt_tmp = iov_cnt;
old_base = iov[iov_cnt - 2].iov_base;
size = iov[iov_cnt - 1].iov_len +
g_test_rand_int_range(1, iov[iov_cnt - 2].iov_len);
ret = iov_discard_back(iov, &iov_cnt_tmp, size);
g_assert(ret == size);
g_assert(iov_cnt_tmp == iov_cnt - 1);
g_assert(iov[iov_cnt - 2].iov_base == old_base);
iov_free(iov, iov_cnt);
}
int main(int argc, char **argv)
{
g_test_init(&argc, &argv, NULL);
g_test_rand_int();
g_test_add_func("/basic/iov/from-to-buf", test_to_from_buf);
g_test_add_func("/basic/iov/io", test_io);
g_test_add_func("/basic/iov/discard-front", test_discard_front);
g_test_add_func("/basic/iov/discard-back", test_discard_back);
return g_test_run();
}

9
trace-events
View File

@ -98,6 +98,15 @@ virtio_blk_rw_complete(void *req, int ret) "req %p ret %d"
virtio_blk_handle_write(void *req, uint64_t sector, size_t nsectors) "req %p sector %"PRIu64" nsectors %zu"
virtio_blk_handle_read(void *req, uint64_t sector, size_t nsectors) "req %p sector %"PRIu64" nsectors %zu"
# hw/dataplane/virtio-blk.c
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"
virtio_blk_data_plane_complete_request(void *s, unsigned int head, int ret) "dataplane %p head %u ret %d"
# hw/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 *req, void *opaque) "req %p opaque %p"
thread_pool_complete(void *req, void *opaque, int ret) "req %p opaque %p ret %d"