Split the QEMU buffered file code out (977184db) · Commits · SUMMER2020 / students / proj-2021291

migration/Makefile.objs

+1 −1

Original line number	Diff line number	Diff line
		common-obj-y += migration.o tcp.o
		common-obj-y += vmstate.o
		common-obj-y += qemu-file.o qemu-file-unix.o qemu-file-stdio.o
		common-obj-y += qemu-file.o qemu-file-buf.o qemu-file-unix.o qemu-file-stdio.o
		common-obj-y += xbzrle.o

		common-obj-$(CONFIG_RDMA) += rdma.o

migration/qemu-file-buf.c

0 → 100644

+486 −0

Original line number	Diff line number	Diff line
		/*
		* QEMU System Emulator
		*
		* Copyright (c) 2003-2008 Fabrice Bellard
		*
		* 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-common.h"
		#include "qemu/iov.h"
		#include "qemu/sockets.h"
		#include "block/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;
		}

		/**
		* Create a deep copy of the given QEMUSizedBuffer.
		*
		* @qsb: A QEMUSizedBuffer
		*
		* Returns a clone of @qsb or NULL on allocation failure
		*/
		QEMUSizedBuffer qsb_clone(const QEMUSizedBuffer qsb)
		{
		QEMUSizedBuffer *out = qsb_create(NULL, qsb_get_length(qsb));
		size_t i;
		ssize_t res;
		off_t pos = 0;

		if (!out) {
		return NULL;
		}

		for (i = 0; i < qsb->n_iov; i++) {
		res = qsb_write_at(out, qsb->iov[i].iov_base,
		pos, qsb->iov[i].iov_len);
		if (res < 0) {
		qsb_free(out);
		return NULL;
		}
		pos += res;
		}

		return out;
		}

		typedef struct QEMUBuffer {
		QEMUSizedBuffer *qsb;
		QEMUFile *file;
		} QEMUBuffer;

		static int buf_get_buffer(void opaque, uint8_t buf, int64_t pos, int 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 int buf_put_buffer(void opaque, const uint8_t buf,
		int64_t pos, int size)
		{
		QEMUBuffer *s = opaque;

		return qsb_write_at(s->qsb, buf, pos, size);
		}

		static int buf_close(void *opaque)
		{
		QEMUBuffer *s = opaque;

		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_malloc0(sizeof(QEMUBuffer));
		if (mode[0] == 'r') {
		s->qsb = input;
		}

		if (s->qsb == NULL) {
		s->qsb = qsb_create(NULL, 0);
		}
		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;
		}

migration/qemu-file.c

+0 −455

Original line number	Diff line number	Diff line
		@@ -517,458 +517,3 @@ uint64_t qemu_get_be64(QEMUFile *f)
		v \|= qemu_get_be32(f);
		return v;
		}

		#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;
		}

		/**
		* Create a deep copy of the given QEMUSizedBuffer.
		*
		* @qsb: A QEMUSizedBuffer
		*
		* Returns a clone of @qsb or NULL on allocation failure
		*/
		QEMUSizedBuffer qsb_clone(const QEMUSizedBuffer qsb)
		{
		QEMUSizedBuffer *out = qsb_create(NULL, qsb_get_length(qsb));
		size_t i;
		ssize_t res;
		off_t pos = 0;

		if (!out) {
		return NULL;
		}

		for (i = 0; i < qsb->n_iov; i++) {
		res = qsb_write_at(out, qsb->iov[i].iov_base,
		pos, qsb->iov[i].iov_len);
		if (res < 0) {
		qsb_free(out);
		return NULL;
		}
		pos += res;
		}

		return out;
		}

		typedef struct QEMUBuffer {
		QEMUSizedBuffer *qsb;
		QEMUFile *file;
		} QEMUBuffer;

		static int buf_get_buffer(void opaque, uint8_t buf, int64_t pos, int 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 int buf_put_buffer(void opaque, const uint8_t buf,
		int64_t pos, int size)
		{
		QEMUBuffer *s = opaque;

		return qsb_write_at(s->qsb, buf, pos, size);
		}

		static int buf_close(void *opaque)
		{
		QEMUBuffer *s = opaque;

		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_malloc0(sizeof(QEMUBuffer));
		if (mode[0] == 'r') {
		s->qsb = input;
		}

		if (s->qsb == NULL) {
		s->qsb = qsb_create(NULL, 0);
		}
		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;
		}

tests/Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -260,7 +260,8 @@ tests/test-qdev-global-props$(EXESUF): tests/test-qdev-global-props.o \
		$(test-qapi-obj-y) \
		libqemuutil.a libqemustub.a
		tests/test-vmstate$(EXESUF): tests/test-vmstate.o \
		migration/vmstate.o migration/qemu-file.o migration/qemu-file-unix.o \
		migration/vmstate.o migration/qemu-file.o migration/qemu-file-buf.o \
		migration/qemu-file-unix.o \
		libqemuutil.a libqemustub.a

		tests/test-qapi-types.c tests/test-qapi-types.h :\