diff options
Diffstat (limited to 'qemu/migration/qemu-file-buf.c')
| -rw-r--r-- | qemu/migration/qemu-file-buf.c | 464 |
1 files changed, 0 insertions, 464 deletions
diff --git a/qemu/migration/qemu-file-buf.c b/qemu/migration/qemu-file-buf.c deleted file mode 100644 index 7b8e78e99..000000000 --- a/qemu/migration/qemu-file-buf.c +++ /dev/null @@ -1,464 +0,0 @@ -/* - * QEMU System Emulator - * - * Copyright (c) 2003-2008 Fabrice Bellard - * Copyright (c) 2014 IBM Corp. - * - * Authors: - * Stefan Berger <stefanb@linux.vnet.ibm.com> - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ -#include "qemu/osdep.h" -#include "qemu-common.h" -#include "qemu/error-report.h" -#include "qemu/iov.h" -#include "qemu/sockets.h" -#include "qemu/coroutine.h" -#include "migration/migration.h" -#include "migration/qemu-file.h" -#include "migration/qemu-file-internal.h" -#include "trace.h" - -#define QSB_CHUNK_SIZE (1 << 10) -#define QSB_MAX_CHUNK_SIZE (16 * QSB_CHUNK_SIZE) - -/** - * Create a QEMUSizedBuffer - * This type of buffer uses scatter-gather lists internally and - * can grow to any size. Any data array in the scatter-gather list - * can hold different amount of bytes. - * - * @buffer: Optional buffer to copy into the QSB - * @len: size of initial buffer; if @buffer is given, buffer must - * hold at least len bytes - * - * Returns a pointer to a QEMUSizedBuffer or NULL on allocation failure - */ -QEMUSizedBuffer *qsb_create(const uint8_t *buffer, size_t len) -{ - QEMUSizedBuffer *qsb; - size_t alloc_len, num_chunks, i, to_copy; - size_t chunk_size = (len > QSB_MAX_CHUNK_SIZE) - ? QSB_MAX_CHUNK_SIZE - : QSB_CHUNK_SIZE; - - num_chunks = DIV_ROUND_UP(len ? len : QSB_CHUNK_SIZE, chunk_size); - alloc_len = num_chunks * chunk_size; - - qsb = g_try_new0(QEMUSizedBuffer, 1); - if (!qsb) { - return NULL; - } - - qsb->iov = g_try_new0(struct iovec, num_chunks); - if (!qsb->iov) { - g_free(qsb); - return NULL; - } - - qsb->n_iov = num_chunks; - - for (i = 0; i < num_chunks; i++) { - qsb->iov[i].iov_base = g_try_malloc0(chunk_size); - if (!qsb->iov[i].iov_base) { - /* qsb_free is safe since g_free can cope with NULL */ - qsb_free(qsb); - return NULL; - } - - qsb->iov[i].iov_len = chunk_size; - if (buffer) { - to_copy = (len - qsb->used) > chunk_size - ? chunk_size : (len - qsb->used); - memcpy(qsb->iov[i].iov_base, &buffer[qsb->used], to_copy); - qsb->used += to_copy; - } - } - - qsb->size = alloc_len; - - return qsb; -} - -/** - * Free the QEMUSizedBuffer - * - * @qsb: The QEMUSizedBuffer to free - */ -void qsb_free(QEMUSizedBuffer *qsb) -{ - size_t i; - - if (!qsb) { - return; - } - - for (i = 0; i < qsb->n_iov; i++) { - g_free(qsb->iov[i].iov_base); - } - g_free(qsb->iov); - g_free(qsb); -} - -/** - * Get the number of used bytes in the QEMUSizedBuffer - * - * @qsb: A QEMUSizedBuffer - * - * Returns the number of bytes currently used in this buffer - */ -size_t qsb_get_length(const QEMUSizedBuffer *qsb) -{ - return qsb->used; -} - -/** - * Set the length of the buffer; the primary usage of this - * function is to truncate the number of used bytes in the buffer. - * The size will not be extended beyond the current number of - * allocated bytes in the QEMUSizedBuffer. - * - * @qsb: A QEMUSizedBuffer - * @new_len: The new length of bytes in the buffer - * - * Returns the number of bytes the buffer was truncated or extended - * to. - */ -size_t qsb_set_length(QEMUSizedBuffer *qsb, size_t new_len) -{ - if (new_len <= qsb->size) { - qsb->used = new_len; - } else { - qsb->used = qsb->size; - } - return qsb->used; -} - -/** - * Get the iovec that holds the data for a given position @pos. - * - * @qsb: A QEMUSizedBuffer - * @pos: The index of a byte in the buffer - * @d_off: Pointer to an offset that this function will indicate - * at what position within the returned iovec the byte - * is to be found - * - * Returns the index of the iovec that holds the byte at the given - * index @pos in the byte stream; a negative number if the iovec - * for the given position @pos does not exist. - */ -static ssize_t qsb_get_iovec(const QEMUSizedBuffer *qsb, - off_t pos, off_t *d_off) -{ - ssize_t i; - off_t curr = 0; - - if (pos > qsb->used) { - return -1; - } - - for (i = 0; i < qsb->n_iov; i++) { - if (curr + qsb->iov[i].iov_len > pos) { - *d_off = pos - curr; - return i; - } - curr += qsb->iov[i].iov_len; - } - return -1; -} - -/* - * Convert the QEMUSizedBuffer into a flat buffer. - * - * Note: If at all possible, try to avoid this function since it - * may unnecessarily copy memory around. - * - * @qsb: pointer to QEMUSizedBuffer - * @start: offset to start at - * @count: number of bytes to copy - * @buf: a pointer to a buffer to write into (at least @count bytes) - * - * Returns the number of bytes copied into the output buffer - */ -ssize_t qsb_get_buffer(const QEMUSizedBuffer *qsb, off_t start, - size_t count, uint8_t *buffer) -{ - const struct iovec *iov; - size_t to_copy, all_copy; - ssize_t index; - off_t s_off; - off_t d_off = 0; - char *s; - - if (start > qsb->used) { - return 0; - } - - all_copy = qsb->used - start; - if (all_copy > count) { - all_copy = count; - } else { - count = all_copy; - } - - index = qsb_get_iovec(qsb, start, &s_off); - if (index < 0) { - return 0; - } - - while (all_copy > 0) { - iov = &qsb->iov[index]; - - s = iov->iov_base; - - to_copy = iov->iov_len - s_off; - if (to_copy > all_copy) { - to_copy = all_copy; - } - memcpy(&buffer[d_off], &s[s_off], to_copy); - - d_off += to_copy; - all_copy -= to_copy; - - s_off = 0; - index++; - } - - return count; -} - -/** - * Grow the QEMUSizedBuffer to the given size and allocate - * memory for it. - * - * @qsb: A QEMUSizedBuffer - * @new_size: The new size of the buffer - * - * Return: - * a negative error code in case of memory allocation failure - * or - * the new size of the buffer. The returned size may be greater or equal - * to @new_size. - */ -static ssize_t qsb_grow(QEMUSizedBuffer *qsb, size_t new_size) -{ - size_t needed_chunks, i; - - if (qsb->size < new_size) { - struct iovec *new_iov; - size_t size_diff = new_size - qsb->size; - size_t chunk_size = (size_diff > QSB_MAX_CHUNK_SIZE) - ? QSB_MAX_CHUNK_SIZE : QSB_CHUNK_SIZE; - - needed_chunks = DIV_ROUND_UP(size_diff, chunk_size); - - new_iov = g_try_new(struct iovec, qsb->n_iov + needed_chunks); - if (new_iov == NULL) { - return -ENOMEM; - } - - /* Allocate new chunks as needed into new_iov */ - for (i = qsb->n_iov; i < qsb->n_iov + needed_chunks; i++) { - new_iov[i].iov_base = g_try_malloc0(chunk_size); - new_iov[i].iov_len = chunk_size; - if (!new_iov[i].iov_base) { - size_t j; - - /* Free previously allocated new chunks */ - for (j = qsb->n_iov; j < i; j++) { - g_free(new_iov[j].iov_base); - } - g_free(new_iov); - - return -ENOMEM; - } - } - - /* - * Now we can't get any allocation errors, copy over to new iov - * and switch. - */ - for (i = 0; i < qsb->n_iov; i++) { - new_iov[i] = qsb->iov[i]; - } - - qsb->n_iov += needed_chunks; - g_free(qsb->iov); - qsb->iov = new_iov; - qsb->size += (needed_chunks * chunk_size); - } - - return qsb->size; -} - -/** - * Write into the QEMUSizedBuffer at a given position and a given - * number of bytes. This function will automatically grow the - * QEMUSizedBuffer. - * - * @qsb: A QEMUSizedBuffer - * @source: A byte array to copy data from - * @pos: The position within the @qsb to write data to - * @size: The number of bytes to copy into the @qsb - * - * Returns @size or a negative error code in case of memory allocation failure, - * or with an invalid 'pos' - */ -ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *source, - off_t pos, size_t count) -{ - ssize_t rc = qsb_grow(qsb, pos + count); - size_t to_copy; - size_t all_copy = count; - const struct iovec *iov; - ssize_t index; - char *dest; - off_t d_off, s_off = 0; - - if (rc < 0) { - return rc; - } - - if (pos + count > qsb->used) { - qsb->used = pos + count; - } - - index = qsb_get_iovec(qsb, pos, &d_off); - if (index < 0) { - return -EINVAL; - } - - while (all_copy > 0) { - iov = &qsb->iov[index]; - - dest = iov->iov_base; - - to_copy = iov->iov_len - d_off; - if (to_copy > all_copy) { - to_copy = all_copy; - } - - memcpy(&dest[d_off], &source[s_off], to_copy); - - s_off += to_copy; - all_copy -= to_copy; - - d_off = 0; - index++; - } - - return count; -} - -typedef struct QEMUBuffer { - QEMUSizedBuffer *qsb; - QEMUFile *file; - bool qsb_allocated; -} QEMUBuffer; - -static ssize_t buf_get_buffer(void *opaque, uint8_t *buf, int64_t pos, - size_t size) -{ - QEMUBuffer *s = opaque; - ssize_t len = qsb_get_length(s->qsb) - pos; - - if (len <= 0) { - return 0; - } - - if (len > size) { - len = size; - } - return qsb_get_buffer(s->qsb, pos, len, buf); -} - -static ssize_t buf_put_buffer(void *opaque, const uint8_t *buf, - int64_t pos, size_t size) -{ - QEMUBuffer *s = opaque; - - return qsb_write_at(s->qsb, buf, pos, size); -} - -static int buf_close(void *opaque) -{ - QEMUBuffer *s = opaque; - - if (s->qsb_allocated) { - qsb_free(s->qsb); - } - - g_free(s); - - return 0; -} - -const QEMUSizedBuffer *qemu_buf_get(QEMUFile *f) -{ - QEMUBuffer *p; - - qemu_fflush(f); - - p = f->opaque; - - return p->qsb; -} - -static const QEMUFileOps buf_read_ops = { - .get_buffer = buf_get_buffer, - .close = buf_close, -}; - -static const QEMUFileOps buf_write_ops = { - .put_buffer = buf_put_buffer, - .close = buf_close, -}; - -QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input) -{ - QEMUBuffer *s; - - if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || - mode[1] != '\0') { - error_report("qemu_bufopen: Argument validity check failed"); - return NULL; - } - - s = g_new0(QEMUBuffer, 1); - s->qsb = input; - - if (s->qsb == NULL) { - s->qsb = qsb_create(NULL, 0); - s->qsb_allocated = true; - } - if (!s->qsb) { - g_free(s); - error_report("qemu_bufopen: qsb_create failed"); - return NULL; - } - - - if (mode[0] == 'r') { - s->file = qemu_fopen_ops(s, &buf_read_ops); - } else { - s->file = qemu_fopen_ops(s, &buf_write_ops); - } - return s->file; -} |