1049 lines
30 KiB
C
1049 lines
30 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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/*
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* libblkio BlockDriver
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*
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* Copyright Red Hat, Inc.
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*
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* Author:
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* Stefan Hajnoczi <stefanha@redhat.com>
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*/
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#include "qemu/osdep.h"
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#include <blkio.h>
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#include "block/block_int.h"
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#include "exec/memory.h"
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#include "exec/cpu-common.h" /* for qemu_ram_get_fd() */
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#include "qapi/error.h"
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#include "qemu/error-report.h"
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#include "qapi/qmp/qdict.h"
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#include "qemu/module.h"
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#include "exec/memory.h" /* for ram_block_discard_disable() */
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#include "block/block-io.h"
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/*
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* Keep the QEMU BlockDriver names identical to the libblkio driver names.
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* Using macros instead of typing out the string literals avoids typos.
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*/
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#define DRIVER_IO_URING "io_uring"
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#define DRIVER_NVME_IO_URING "nvme-io_uring"
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#define DRIVER_VIRTIO_BLK_VFIO_PCI "virtio-blk-vfio-pci"
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#define DRIVER_VIRTIO_BLK_VHOST_USER "virtio-blk-vhost-user"
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#define DRIVER_VIRTIO_BLK_VHOST_VDPA "virtio-blk-vhost-vdpa"
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/*
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* Allocated bounce buffers are kept in a list sorted by buffer address.
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*/
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typedef struct BlkioBounceBuf {
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QLIST_ENTRY(BlkioBounceBuf) next;
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/* The bounce buffer */
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struct iovec buf;
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} BlkioBounceBuf;
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typedef struct {
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/*
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* libblkio is not thread-safe so this lock protects ->blkio and
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* ->blkioq.
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*/
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QemuMutex blkio_lock;
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struct blkio *blkio;
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struct blkioq *blkioq; /* make this multi-queue in the future... */
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int completion_fd;
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/*
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* Polling fetches the next completion into this field.
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*
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* No lock is necessary since only one thread calls aio_poll() and invokes
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* fd and poll handlers.
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*/
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struct blkio_completion poll_completion;
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/*
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* Protects ->bounce_pool, ->bounce_bufs, ->bounce_available.
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*
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* Lock ordering: ->bounce_lock before ->blkio_lock.
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*/
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CoMutex bounce_lock;
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/* Bounce buffer pool */
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struct blkio_mem_region bounce_pool;
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/* Sorted list of allocated bounce buffers */
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QLIST_HEAD(, BlkioBounceBuf) bounce_bufs;
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/* Queue for coroutines waiting for bounce buffer space */
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CoQueue bounce_available;
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/* The value of the "mem-region-alignment" property */
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size_t mem_region_alignment;
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/* Can we skip adding/deleting blkio_mem_regions? */
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bool needs_mem_regions;
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/* Are file descriptors necessary for blkio_mem_regions? */
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bool needs_mem_region_fd;
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/* Are madvise(MADV_DONTNEED)-style operations unavailable? */
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bool may_pin_mem_regions;
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} BDRVBlkioState;
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/* Called with s->bounce_lock held */
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static int blkio_resize_bounce_pool(BDRVBlkioState *s, int64_t bytes)
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{
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/* There can be no allocated bounce buffers during resize */
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assert(QLIST_EMPTY(&s->bounce_bufs));
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/* Pad size to reduce frequency of resize calls */
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bytes += 128 * 1024;
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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int ret;
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if (s->bounce_pool.addr) {
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blkio_unmap_mem_region(s->blkio, &s->bounce_pool);
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blkio_free_mem_region(s->blkio, &s->bounce_pool);
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memset(&s->bounce_pool, 0, sizeof(s->bounce_pool));
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}
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/* Automatically freed when s->blkio is destroyed */
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ret = blkio_alloc_mem_region(s->blkio, &s->bounce_pool, bytes);
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if (ret < 0) {
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return ret;
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}
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ret = blkio_map_mem_region(s->blkio, &s->bounce_pool);
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if (ret < 0) {
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blkio_free_mem_region(s->blkio, &s->bounce_pool);
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memset(&s->bounce_pool, 0, sizeof(s->bounce_pool));
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return ret;
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}
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}
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return 0;
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}
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/* Called with s->bounce_lock held */
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static bool
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blkio_do_alloc_bounce_buffer(BDRVBlkioState *s, BlkioBounceBuf *bounce,
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int64_t bytes)
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{
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void *addr = s->bounce_pool.addr;
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BlkioBounceBuf *cur = NULL;
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BlkioBounceBuf *prev = NULL;
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ptrdiff_t space;
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/*
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* This is just a linear search over the holes between requests. An
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* efficient allocator would be nice.
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*/
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QLIST_FOREACH(cur, &s->bounce_bufs, next) {
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space = cur->buf.iov_base - addr;
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if (bytes <= space) {
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QLIST_INSERT_BEFORE(cur, bounce, next);
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bounce->buf.iov_base = addr;
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bounce->buf.iov_len = bytes;
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return true;
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}
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addr = cur->buf.iov_base + cur->buf.iov_len;
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prev = cur;
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}
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/* Is there space after the last request? */
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space = s->bounce_pool.addr + s->bounce_pool.len - addr;
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if (bytes > space) {
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return false;
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}
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if (prev) {
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QLIST_INSERT_AFTER(prev, bounce, next);
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} else {
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QLIST_INSERT_HEAD(&s->bounce_bufs, bounce, next);
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}
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bounce->buf.iov_base = addr;
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bounce->buf.iov_len = bytes;
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return true;
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}
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static int coroutine_fn
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blkio_alloc_bounce_buffer(BDRVBlkioState *s, BlkioBounceBuf *bounce,
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int64_t bytes)
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{
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/*
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* Ensure fairness: first time around we join the back of the queue,
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* subsequently we join the front so we don't lose our place.
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*/
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CoQueueWaitFlags wait_flags = 0;
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QEMU_LOCK_GUARD(&s->bounce_lock);
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/* Ensure fairness: don't even try if other requests are already waiting */
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if (!qemu_co_queue_empty(&s->bounce_available)) {
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qemu_co_queue_wait_flags(&s->bounce_available, &s->bounce_lock,
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wait_flags);
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wait_flags = CO_QUEUE_WAIT_FRONT;
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}
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while (true) {
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if (blkio_do_alloc_bounce_buffer(s, bounce, bytes)) {
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/* Kick the next queued request since there may be space */
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qemu_co_queue_next(&s->bounce_available);
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return 0;
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}
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/*
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* If there are no in-flight requests then the pool was simply too
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* small.
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*/
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if (QLIST_EMPTY(&s->bounce_bufs)) {
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bool ok;
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int ret;
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ret = blkio_resize_bounce_pool(s, bytes);
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if (ret < 0) {
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/* Kick the next queued request since that may fail too */
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qemu_co_queue_next(&s->bounce_available);
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return ret;
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}
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ok = blkio_do_alloc_bounce_buffer(s, bounce, bytes);
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assert(ok); /* must have space this time */
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return 0;
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}
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qemu_co_queue_wait_flags(&s->bounce_available, &s->bounce_lock,
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wait_flags);
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wait_flags = CO_QUEUE_WAIT_FRONT;
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}
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}
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static void coroutine_fn blkio_free_bounce_buffer(BDRVBlkioState *s,
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BlkioBounceBuf *bounce)
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{
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QEMU_LOCK_GUARD(&s->bounce_lock);
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QLIST_REMOVE(bounce, next);
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/* Wake up waiting coroutines since space may now be available */
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qemu_co_queue_next(&s->bounce_available);
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}
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/* For async to .bdrv_co_*() conversion */
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typedef struct {
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Coroutine *coroutine;
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int ret;
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} BlkioCoData;
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static void blkio_completion_fd_read(void *opaque)
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{
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BlockDriverState *bs = opaque;
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BDRVBlkioState *s = bs->opaque;
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uint64_t val;
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int ret;
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/* Polling may have already fetched a completion */
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if (s->poll_completion.user_data != NULL) {
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BlkioCoData *cod = s->poll_completion.user_data;
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cod->ret = s->poll_completion.ret;
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/* Clear it in case aio_co_wake() enters a nested event loop */
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s->poll_completion.user_data = NULL;
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aio_co_wake(cod->coroutine);
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}
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/* Reset completion fd status */
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ret = read(s->completion_fd, &val, sizeof(val));
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/* Ignore errors, there's nothing we can do */
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(void)ret;
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/*
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* Reading one completion at a time makes nested event loop re-entrancy
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* simple. Change this loop to get multiple completions in one go if it
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* becomes a performance bottleneck.
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*/
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while (true) {
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struct blkio_completion completion;
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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ret = blkioq_do_io(s->blkioq, &completion, 0, 1, NULL);
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}
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if (ret != 1) {
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break;
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}
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BlkioCoData *cod = completion.user_data;
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cod->ret = completion.ret;
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aio_co_wake(cod->coroutine);
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}
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}
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static bool blkio_completion_fd_poll(void *opaque)
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{
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BlockDriverState *bs = opaque;
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BDRVBlkioState *s = bs->opaque;
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int ret;
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/* Just in case we already fetched a completion */
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if (s->poll_completion.user_data != NULL) {
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return true;
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}
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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ret = blkioq_do_io(s->blkioq, &s->poll_completion, 0, 1, NULL);
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}
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return ret == 1;
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}
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static void blkio_completion_fd_poll_ready(void *opaque)
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{
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blkio_completion_fd_read(opaque);
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}
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static void blkio_attach_aio_context(BlockDriverState *bs,
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AioContext *new_context)
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{
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BDRVBlkioState *s = bs->opaque;
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aio_set_fd_handler(new_context,
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s->completion_fd,
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false,
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blkio_completion_fd_read,
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NULL,
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blkio_completion_fd_poll,
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blkio_completion_fd_poll_ready,
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bs);
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}
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static void blkio_detach_aio_context(BlockDriverState *bs)
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{
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BDRVBlkioState *s = bs->opaque;
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aio_set_fd_handler(bdrv_get_aio_context(bs),
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s->completion_fd,
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false, NULL, NULL, NULL, NULL, NULL);
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}
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/* Call with s->blkio_lock held to submit I/O after enqueuing a new request */
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static void blkio_submit_io(BlockDriverState *bs)
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{
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if (qatomic_read(&bs->io_plugged) == 0) {
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BDRVBlkioState *s = bs->opaque;
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blkioq_do_io(s->blkioq, NULL, 0, 0, NULL);
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}
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}
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static int coroutine_fn
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blkio_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
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{
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BDRVBlkioState *s = bs->opaque;
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BlkioCoData cod = {
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.coroutine = qemu_coroutine_self(),
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};
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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blkioq_discard(s->blkioq, offset, bytes, &cod, 0);
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blkio_submit_io(bs);
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}
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qemu_coroutine_yield();
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return cod.ret;
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}
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static int coroutine_fn
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blkio_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
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QEMUIOVector *qiov, BdrvRequestFlags flags)
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{
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BlkioCoData cod = {
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.coroutine = qemu_coroutine_self(),
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};
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BDRVBlkioState *s = bs->opaque;
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bool use_bounce_buffer =
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s->needs_mem_regions && !(flags & BDRV_REQ_REGISTERED_BUF);
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BlkioBounceBuf bounce;
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struct iovec *iov = qiov->iov;
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int iovcnt = qiov->niov;
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if (use_bounce_buffer) {
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int ret = blkio_alloc_bounce_buffer(s, &bounce, bytes);
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if (ret < 0) {
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return ret;
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}
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iov = &bounce.buf;
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iovcnt = 1;
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}
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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blkioq_readv(s->blkioq, offset, iov, iovcnt, &cod, 0);
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blkio_submit_io(bs);
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}
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qemu_coroutine_yield();
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if (use_bounce_buffer) {
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if (cod.ret == 0) {
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qemu_iovec_from_buf(qiov, 0,
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bounce.buf.iov_base,
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bounce.buf.iov_len);
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}
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blkio_free_bounce_buffer(s, &bounce);
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}
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return cod.ret;
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}
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static int coroutine_fn blkio_co_pwritev(BlockDriverState *bs, int64_t offset,
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int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags)
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{
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uint32_t blkio_flags = (flags & BDRV_REQ_FUA) ? BLKIO_REQ_FUA : 0;
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BlkioCoData cod = {
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.coroutine = qemu_coroutine_self(),
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};
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BDRVBlkioState *s = bs->opaque;
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bool use_bounce_buffer =
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s->needs_mem_regions && !(flags & BDRV_REQ_REGISTERED_BUF);
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BlkioBounceBuf bounce;
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struct iovec *iov = qiov->iov;
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int iovcnt = qiov->niov;
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if (use_bounce_buffer) {
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int ret = blkio_alloc_bounce_buffer(s, &bounce, bytes);
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if (ret < 0) {
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return ret;
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}
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qemu_iovec_to_buf(qiov, 0, bounce.buf.iov_base, bytes);
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iov = &bounce.buf;
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iovcnt = 1;
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}
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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blkioq_writev(s->blkioq, offset, iov, iovcnt, &cod, blkio_flags);
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blkio_submit_io(bs);
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}
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qemu_coroutine_yield();
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if (use_bounce_buffer) {
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blkio_free_bounce_buffer(s, &bounce);
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}
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return cod.ret;
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}
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static int coroutine_fn blkio_co_flush(BlockDriverState *bs)
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{
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BDRVBlkioState *s = bs->opaque;
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BlkioCoData cod = {
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.coroutine = qemu_coroutine_self(),
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};
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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blkioq_flush(s->blkioq, &cod, 0);
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blkio_submit_io(bs);
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}
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qemu_coroutine_yield();
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return cod.ret;
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}
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static int coroutine_fn blkio_co_pwrite_zeroes(BlockDriverState *bs,
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int64_t offset, int64_t bytes, BdrvRequestFlags flags)
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{
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BDRVBlkioState *s = bs->opaque;
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BlkioCoData cod = {
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.coroutine = qemu_coroutine_self(),
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};
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uint32_t blkio_flags = 0;
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if (flags & BDRV_REQ_FUA) {
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blkio_flags |= BLKIO_REQ_FUA;
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}
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if (!(flags & BDRV_REQ_MAY_UNMAP)) {
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blkio_flags |= BLKIO_REQ_NO_UNMAP;
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}
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if (flags & BDRV_REQ_NO_FALLBACK) {
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blkio_flags |= BLKIO_REQ_NO_FALLBACK;
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}
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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blkioq_write_zeroes(s->blkioq, offset, bytes, &cod, blkio_flags);
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blkio_submit_io(bs);
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}
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qemu_coroutine_yield();
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return cod.ret;
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}
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static void coroutine_fn blkio_co_io_unplug(BlockDriverState *bs)
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{
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BDRVBlkioState *s = bs->opaque;
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WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
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blkio_submit_io(bs);
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}
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}
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typedef enum {
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BMRR_OK,
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BMRR_SKIP,
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BMRR_FAIL,
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} BlkioMemRegionResult;
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/*
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* Produce a struct blkio_mem_region for a given address and size.
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*
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* This function produces identical results when called multiple times with the
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* same arguments. This property is necessary because blkio_unmap_mem_region()
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* must receive the same struct blkio_mem_region field values that were passed
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* to blkio_map_mem_region().
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*/
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static BlkioMemRegionResult
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blkio_mem_region_from_host(BlockDriverState *bs,
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void *host, size_t size,
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struct blkio_mem_region *region,
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Error **errp)
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{
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BDRVBlkioState *s = bs->opaque;
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int fd = -1;
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|
ram_addr_t fd_offset = 0;
|
|
|
|
if (((uintptr_t)host | size) % s->mem_region_alignment) {
|
|
error_setg(errp, "unaligned buf %p with size %zu", host, size);
|
|
return BMRR_FAIL;
|
|
}
|
|
|
|
/* Attempt to find the fd for the underlying memory */
|
|
if (s->needs_mem_region_fd) {
|
|
RAMBlock *ram_block;
|
|
RAMBlock *end_block;
|
|
ram_addr_t offset;
|
|
|
|
/*
|
|
* bdrv_register_buf() is called with the BQL held so mr lives at least
|
|
* until this function returns.
|
|
*/
|
|
ram_block = qemu_ram_block_from_host(host, false, &fd_offset);
|
|
if (ram_block) {
|
|
fd = qemu_ram_get_fd(ram_block);
|
|
}
|
|
if (fd == -1) {
|
|
/*
|
|
* Ideally every RAMBlock would have an fd. pc-bios and other
|
|
* things don't. Luckily they are usually not I/O buffers and we
|
|
* can just ignore them.
|
|
*/
|
|
return BMRR_SKIP;
|
|
}
|
|
|
|
/* Make sure the fd covers the entire range */
|
|
end_block = qemu_ram_block_from_host(host + size - 1, false, &offset);
|
|
if (ram_block != end_block) {
|
|
error_setg(errp, "registered buffer at %p with size %zu extends "
|
|
"beyond RAMBlock", host, size);
|
|
return BMRR_FAIL;
|
|
}
|
|
}
|
|
|
|
*region = (struct blkio_mem_region){
|
|
.addr = host,
|
|
.len = size,
|
|
.fd = fd,
|
|
.fd_offset = fd_offset,
|
|
};
|
|
return BMRR_OK;
|
|
}
|
|
|
|
static bool blkio_register_buf(BlockDriverState *bs, void *host, size_t size,
|
|
Error **errp)
|
|
{
|
|
BDRVBlkioState *s = bs->opaque;
|
|
struct blkio_mem_region region;
|
|
BlkioMemRegionResult region_result;
|
|
int ret;
|
|
|
|
/*
|
|
* Mapping memory regions conflicts with RAM discard (virtio-mem) when
|
|
* there is pinning, so only do it when necessary.
|
|
*/
|
|
if (!s->needs_mem_regions && s->may_pin_mem_regions) {
|
|
return true;
|
|
}
|
|
|
|
region_result = blkio_mem_region_from_host(bs, host, size, ®ion, errp);
|
|
if (region_result == BMRR_SKIP) {
|
|
return true;
|
|
} else if (region_result != BMRR_OK) {
|
|
return false;
|
|
}
|
|
|
|
WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
|
|
ret = blkio_map_mem_region(s->blkio, ®ion);
|
|
}
|
|
|
|
if (ret < 0) {
|
|
error_setg(errp, "Failed to add blkio mem region %p with size %zu: %s",
|
|
host, size, blkio_get_error_msg());
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static void blkio_unregister_buf(BlockDriverState *bs, void *host, size_t size)
|
|
{
|
|
BDRVBlkioState *s = bs->opaque;
|
|
struct blkio_mem_region region;
|
|
|
|
/* See blkio_register_buf() */
|
|
if (!s->needs_mem_regions && s->may_pin_mem_regions) {
|
|
return;
|
|
}
|
|
|
|
if (blkio_mem_region_from_host(bs, host, size, ®ion, NULL) != BMRR_OK) {
|
|
return;
|
|
}
|
|
|
|
WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
|
|
blkio_unmap_mem_region(s->blkio, ®ion);
|
|
}
|
|
}
|
|
|
|
static int blkio_io_uring_open(BlockDriverState *bs, QDict *options, int flags,
|
|
Error **errp)
|
|
{
|
|
const char *filename = qdict_get_str(options, "filename");
|
|
BDRVBlkioState *s = bs->opaque;
|
|
int ret;
|
|
|
|
ret = blkio_set_str(s->blkio, "path", filename);
|
|
qdict_del(options, "filename");
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to set path: %s",
|
|
blkio_get_error_msg());
|
|
return ret;
|
|
}
|
|
|
|
if (flags & BDRV_O_NOCACHE) {
|
|
ret = blkio_set_bool(s->blkio, "direct", true);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to set direct: %s",
|
|
blkio_get_error_msg());
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blkio_nvme_io_uring(BlockDriverState *bs, QDict *options, int flags,
|
|
Error **errp)
|
|
{
|
|
const char *path = qdict_get_try_str(options, "path");
|
|
BDRVBlkioState *s = bs->opaque;
|
|
int ret;
|
|
|
|
if (!path) {
|
|
error_setg(errp, "missing 'path' option");
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = blkio_set_str(s->blkio, "path", path);
|
|
qdict_del(options, "path");
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to set path: %s",
|
|
blkio_get_error_msg());
|
|
return ret;
|
|
}
|
|
|
|
if (!(flags & BDRV_O_NOCACHE)) {
|
|
error_setg(errp, "cache.direct=off is not supported");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blkio_virtio_blk_common_open(BlockDriverState *bs,
|
|
QDict *options, int flags, Error **errp)
|
|
{
|
|
const char *path = qdict_get_try_str(options, "path");
|
|
BDRVBlkioState *s = bs->opaque;
|
|
int ret;
|
|
|
|
if (!path) {
|
|
error_setg(errp, "missing 'path' option");
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = blkio_set_str(s->blkio, "path", path);
|
|
qdict_del(options, "path");
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to set path: %s",
|
|
blkio_get_error_msg());
|
|
return ret;
|
|
}
|
|
|
|
if (!(flags & BDRV_O_NOCACHE)) {
|
|
error_setg(errp, "cache.direct=off is not supported");
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int blkio_file_open(BlockDriverState *bs, QDict *options, int flags,
|
|
Error **errp)
|
|
{
|
|
const char *blkio_driver = bs->drv->protocol_name;
|
|
BDRVBlkioState *s = bs->opaque;
|
|
int ret;
|
|
|
|
ret = blkio_create(blkio_driver, &s->blkio);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "blkio_create failed: %s",
|
|
blkio_get_error_msg());
|
|
return ret;
|
|
}
|
|
|
|
if (strcmp(blkio_driver, DRIVER_IO_URING) == 0) {
|
|
ret = blkio_io_uring_open(bs, options, flags, errp);
|
|
} else if (strcmp(blkio_driver, DRIVER_NVME_IO_URING) == 0) {
|
|
ret = blkio_nvme_io_uring(bs, options, flags, errp);
|
|
} else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VFIO_PCI) == 0) {
|
|
ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
|
|
} else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_USER) == 0) {
|
|
ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
|
|
} else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_VDPA) == 0) {
|
|
ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
|
|
} else {
|
|
g_assert_not_reached();
|
|
}
|
|
if (ret < 0) {
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
|
|
if (!(flags & BDRV_O_RDWR)) {
|
|
ret = blkio_set_bool(s->blkio, "read-only", true);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to set read-only: %s",
|
|
blkio_get_error_msg());
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = blkio_connect(s->blkio);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "blkio_connect failed: %s",
|
|
blkio_get_error_msg());
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
|
|
ret = blkio_get_bool(s->blkio,
|
|
"needs-mem-regions",
|
|
&s->needs_mem_regions);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret,
|
|
"failed to get needs-mem-regions: %s",
|
|
blkio_get_error_msg());
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
|
|
ret = blkio_get_bool(s->blkio,
|
|
"needs-mem-region-fd",
|
|
&s->needs_mem_region_fd);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret,
|
|
"failed to get needs-mem-region-fd: %s",
|
|
blkio_get_error_msg());
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
|
|
ret = blkio_get_uint64(s->blkio,
|
|
"mem-region-alignment",
|
|
&s->mem_region_alignment);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret,
|
|
"failed to get mem-region-alignment: %s",
|
|
blkio_get_error_msg());
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
|
|
ret = blkio_get_bool(s->blkio,
|
|
"may-pin-mem-regions",
|
|
&s->may_pin_mem_regions);
|
|
if (ret < 0) {
|
|
/* Be conservative (assume pinning) if the property is not supported */
|
|
s->may_pin_mem_regions = s->needs_mem_regions;
|
|
}
|
|
|
|
/*
|
|
* Notify if libblkio drivers pin memory and prevent features like
|
|
* virtio-mem from working.
|
|
*/
|
|
if (s->may_pin_mem_regions) {
|
|
ret = ram_block_discard_disable(true);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "ram_block_discard_disable() failed");
|
|
blkio_destroy(&s->blkio);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = blkio_start(s->blkio);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "blkio_start failed: %s",
|
|
blkio_get_error_msg());
|
|
blkio_destroy(&s->blkio);
|
|
if (s->may_pin_mem_regions) {
|
|
ram_block_discard_disable(false);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
bs->supported_write_flags = BDRV_REQ_FUA | BDRV_REQ_REGISTERED_BUF;
|
|
bs->supported_zero_flags = BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP |
|
|
BDRV_REQ_NO_FALLBACK;
|
|
|
|
qemu_mutex_init(&s->blkio_lock);
|
|
qemu_co_mutex_init(&s->bounce_lock);
|
|
qemu_co_queue_init(&s->bounce_available);
|
|
QLIST_INIT(&s->bounce_bufs);
|
|
s->blkioq = blkio_get_queue(s->blkio, 0);
|
|
s->completion_fd = blkioq_get_completion_fd(s->blkioq);
|
|
|
|
blkio_attach_aio_context(bs, bdrv_get_aio_context(bs));
|
|
return 0;
|
|
}
|
|
|
|
static void blkio_close(BlockDriverState *bs)
|
|
{
|
|
BDRVBlkioState *s = bs->opaque;
|
|
|
|
/* There is no destroy() API for s->bounce_lock */
|
|
|
|
qemu_mutex_destroy(&s->blkio_lock);
|
|
blkio_detach_aio_context(bs);
|
|
blkio_destroy(&s->blkio);
|
|
|
|
if (s->may_pin_mem_regions) {
|
|
ram_block_discard_disable(false);
|
|
}
|
|
}
|
|
|
|
static int64_t coroutine_fn blkio_co_getlength(BlockDriverState *bs)
|
|
{
|
|
BDRVBlkioState *s = bs->opaque;
|
|
uint64_t capacity;
|
|
int ret;
|
|
|
|
WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
|
|
ret = blkio_get_uint64(s->blkio, "capacity", &capacity);
|
|
}
|
|
if (ret < 0) {
|
|
return -ret;
|
|
}
|
|
|
|
return capacity;
|
|
}
|
|
|
|
static int coroutine_fn blkio_truncate(BlockDriverState *bs, int64_t offset,
|
|
bool exact, PreallocMode prealloc,
|
|
BdrvRequestFlags flags, Error **errp)
|
|
{
|
|
int64_t current_length;
|
|
|
|
if (prealloc != PREALLOC_MODE_OFF) {
|
|
error_setg(errp, "Unsupported preallocation mode '%s'",
|
|
PreallocMode_str(prealloc));
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
current_length = blkio_co_getlength(bs);
|
|
|
|
if (offset > current_length) {
|
|
error_setg(errp, "Cannot grow device");
|
|
return -EINVAL;
|
|
} else if (exact && offset != current_length) {
|
|
error_setg(errp, "Cannot resize device");
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blkio_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void blkio_refresh_limits(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BDRVBlkioState *s = bs->opaque;
|
|
QEMU_LOCK_GUARD(&s->blkio_lock);
|
|
int value;
|
|
int ret;
|
|
|
|
ret = blkio_get_int(s->blkio, "request-alignment", &value);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to get \"request-alignment\": %s",
|
|
blkio_get_error_msg());
|
|
return;
|
|
}
|
|
bs->bl.request_alignment = value;
|
|
if (bs->bl.request_alignment < 1 ||
|
|
bs->bl.request_alignment >= INT_MAX ||
|
|
!is_power_of_2(bs->bl.request_alignment)) {
|
|
error_setg(errp, "invalid \"request-alignment\" value %" PRIu32 ", "
|
|
"must be a power of 2 less than INT_MAX",
|
|
bs->bl.request_alignment);
|
|
return;
|
|
}
|
|
|
|
ret = blkio_get_int(s->blkio, "optimal-io-size", &value);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to get \"optimal-io-size\": %s",
|
|
blkio_get_error_msg());
|
|
return;
|
|
}
|
|
bs->bl.opt_transfer = value;
|
|
if (bs->bl.opt_transfer > INT_MAX ||
|
|
(bs->bl.opt_transfer % bs->bl.request_alignment)) {
|
|
error_setg(errp, "invalid \"optimal-io-size\" value %" PRIu32 ", must "
|
|
"be a multiple of %" PRIu32, bs->bl.opt_transfer,
|
|
bs->bl.request_alignment);
|
|
return;
|
|
}
|
|
|
|
ret = blkio_get_int(s->blkio, "max-transfer", &value);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to get \"max-transfer\": %s",
|
|
blkio_get_error_msg());
|
|
return;
|
|
}
|
|
bs->bl.max_transfer = value;
|
|
if ((bs->bl.max_transfer % bs->bl.request_alignment) ||
|
|
(bs->bl.opt_transfer && (bs->bl.max_transfer % bs->bl.opt_transfer))) {
|
|
error_setg(errp, "invalid \"max-transfer\" value %" PRIu32 ", must be "
|
|
"a multiple of %" PRIu32 " and %" PRIu32 " (if non-zero)",
|
|
bs->bl.max_transfer, bs->bl.request_alignment,
|
|
bs->bl.opt_transfer);
|
|
return;
|
|
}
|
|
|
|
ret = blkio_get_int(s->blkio, "buf-alignment", &value);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to get \"buf-alignment\": %s",
|
|
blkio_get_error_msg());
|
|
return;
|
|
}
|
|
if (value < 1) {
|
|
error_setg(errp, "invalid \"buf-alignment\" value %d, must be "
|
|
"positive", value);
|
|
return;
|
|
}
|
|
bs->bl.min_mem_alignment = value;
|
|
|
|
ret = blkio_get_int(s->blkio, "optimal-buf-alignment", &value);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret,
|
|
"failed to get \"optimal-buf-alignment\": %s",
|
|
blkio_get_error_msg());
|
|
return;
|
|
}
|
|
if (value < 1) {
|
|
error_setg(errp, "invalid \"optimal-buf-alignment\" value %d, "
|
|
"must be positive", value);
|
|
return;
|
|
}
|
|
bs->bl.opt_mem_alignment = value;
|
|
|
|
ret = blkio_get_int(s->blkio, "max-segments", &value);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "failed to get \"max-segments\": %s",
|
|
blkio_get_error_msg());
|
|
return;
|
|
}
|
|
if (value < 1) {
|
|
error_setg(errp, "invalid \"max-segments\" value %d, must be positive",
|
|
value);
|
|
return;
|
|
}
|
|
bs->bl.max_iov = value;
|
|
}
|
|
|
|
/*
|
|
* TODO
|
|
* Missing libblkio APIs:
|
|
* - block_status
|
|
* - co_invalidate_cache
|
|
*
|
|
* Out of scope?
|
|
* - create
|
|
* - truncate
|
|
*/
|
|
|
|
#define BLKIO_DRIVER(name, ...) \
|
|
{ \
|
|
.format_name = name, \
|
|
.protocol_name = name, \
|
|
.instance_size = sizeof(BDRVBlkioState), \
|
|
.bdrv_file_open = blkio_file_open, \
|
|
.bdrv_close = blkio_close, \
|
|
.bdrv_co_getlength = blkio_co_getlength, \
|
|
.bdrv_co_truncate = blkio_truncate, \
|
|
.bdrv_get_info = blkio_get_info, \
|
|
.bdrv_attach_aio_context = blkio_attach_aio_context, \
|
|
.bdrv_detach_aio_context = blkio_detach_aio_context, \
|
|
.bdrv_co_pdiscard = blkio_co_pdiscard, \
|
|
.bdrv_co_preadv = blkio_co_preadv, \
|
|
.bdrv_co_pwritev = blkio_co_pwritev, \
|
|
.bdrv_co_flush_to_disk = blkio_co_flush, \
|
|
.bdrv_co_pwrite_zeroes = blkio_co_pwrite_zeroes, \
|
|
.bdrv_co_io_unplug = blkio_co_io_unplug, \
|
|
.bdrv_refresh_limits = blkio_refresh_limits, \
|
|
.bdrv_register_buf = blkio_register_buf, \
|
|
.bdrv_unregister_buf = blkio_unregister_buf, \
|
|
__VA_ARGS__ \
|
|
}
|
|
|
|
static BlockDriver bdrv_io_uring = BLKIO_DRIVER(
|
|
DRIVER_IO_URING,
|
|
.bdrv_needs_filename = true,
|
|
);
|
|
|
|
static BlockDriver bdrv_nvme_io_uring = BLKIO_DRIVER(
|
|
DRIVER_NVME_IO_URING,
|
|
);
|
|
|
|
static BlockDriver bdrv_virtio_blk_vfio_pci = BLKIO_DRIVER(
|
|
DRIVER_VIRTIO_BLK_VFIO_PCI
|
|
);
|
|
|
|
static BlockDriver bdrv_virtio_blk_vhost_user = BLKIO_DRIVER(
|
|
DRIVER_VIRTIO_BLK_VHOST_USER
|
|
);
|
|
|
|
static BlockDriver bdrv_virtio_blk_vhost_vdpa = BLKIO_DRIVER(
|
|
DRIVER_VIRTIO_BLK_VHOST_VDPA
|
|
);
|
|
|
|
static void bdrv_blkio_init(void)
|
|
{
|
|
bdrv_register(&bdrv_io_uring);
|
|
bdrv_register(&bdrv_nvme_io_uring);
|
|
bdrv_register(&bdrv_virtio_blk_vfio_pci);
|
|
bdrv_register(&bdrv_virtio_blk_vhost_user);
|
|
bdrv_register(&bdrv_virtio_blk_vhost_vdpa);
|
|
}
|
|
|
|
block_init(bdrv_blkio_init);
|