* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
+#include "qemu/osdep.h"
#include <zlib.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 "migration.h"
+#include "qemu-file.h"
#include "trace.h"
+#define IO_BUF_SIZE 32768
+#define MAX_IOV_SIZE MIN(IOV_MAX, 64)
+
+struct QEMUFile {
+ const QEMUFileOps *ops;
+ const QEMUFileHooks *hooks;
+ void *opaque;
+
+ int64_t bytes_xfer;
+ int64_t xfer_limit;
+
+ int64_t pos; /* start of buffer when writing, end of buffer
+ when reading */
+ int buf_index;
+ int buf_size; /* 0 when writing */
+ uint8_t buf[IO_BUF_SIZE];
+
+ DECLARE_BITMAP(may_free, MAX_IOV_SIZE);
+ struct iovec iov[MAX_IOV_SIZE];
+ unsigned int iovcnt;
+
+ int last_error;
+};
+
/*
* Stop a file from being read/written - not all backing files can do this
* typically only sockets can.
return f->ops->shut_down(f->opaque, true, true);
}
+/*
+ * Result: QEMUFile* for a 'return path' for comms in the opposite direction
+ * NULL if not available
+ */
+QEMUFile *qemu_file_get_return_path(QEMUFile *f)
+{
+ if (!f->ops->get_return_path) {
+ return NULL;
+ }
+ return f->ops->get_return_path(f->opaque);
+}
+
bool qemu_file_mode_is_not_valid(const char *mode)
{
if (mode == NULL ||
return f;
}
+
+void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks)
+{
+ f->hooks = hooks;
+}
+
/*
* Get last error for stream f
*
bool qemu_file_is_writable(QEMUFile *f)
{
- return f->ops->writev_buffer || f->ops->put_buffer;
+ return f->ops->writev_buffer;
+}
+
+static void qemu_iovec_release_ram(QEMUFile *f)
+{
+ struct iovec iov;
+ unsigned long idx;
+
+ /* Find and release all the contiguous memory ranges marked as may_free. */
+ idx = find_next_bit(f->may_free, f->iovcnt, 0);
+ if (idx >= f->iovcnt) {
+ return;
+ }
+ iov = f->iov[idx];
+
+ /* The madvise() in the loop is called for iov within a continuous range and
+ * then reinitialize the iov. And in the end, madvise() is called for the
+ * last iov.
+ */
+ while ((idx = find_next_bit(f->may_free, f->iovcnt, idx + 1)) < f->iovcnt) {
+ /* check for adjacent buffer and coalesce them */
+ if (iov.iov_base + iov.iov_len == f->iov[idx].iov_base) {
+ iov.iov_len += f->iov[idx].iov_len;
+ continue;
+ }
+ if (qemu_madvise(iov.iov_base, iov.iov_len, QEMU_MADV_DONTNEED) < 0) {
+ error_report("migrate: madvise DONTNEED failed %p %zd: %s",
+ iov.iov_base, iov.iov_len, strerror(errno));
+ }
+ iov = f->iov[idx];
+ }
+ if (qemu_madvise(iov.iov_base, iov.iov_len, QEMU_MADV_DONTNEED) < 0) {
+ error_report("migrate: madvise DONTNEED failed %p %zd: %s",
+ iov.iov_base, iov.iov_len, strerror(errno));
+ }
+ memset(f->may_free, 0, sizeof(f->may_free));
}
/**
* Flushes QEMUFile buffer
*
* If there is writev_buffer QEMUFileOps it uses it otherwise uses
- * put_buffer ops.
+ * put_buffer ops. This will flush all pending data. If data was
+ * only partially flushed, it will set an error state.
*/
void qemu_fflush(QEMUFile *f)
{
ssize_t ret = 0;
+ ssize_t expect = 0;
if (!qemu_file_is_writable(f)) {
return;
}
- if (f->ops->writev_buffer) {
- if (f->iovcnt > 0) {
- ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos);
- }
- } else {
- if (f->buf_index > 0) {
- ret = f->ops->put_buffer(f->opaque, f->buf, f->pos, f->buf_index);
- }
+ if (f->iovcnt > 0) {
+ expect = iov_size(f->iov, f->iovcnt);
+ ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos);
+
+ qemu_iovec_release_ram(f);
}
+
if (ret >= 0) {
f->pos += ret;
}
+ /* We expect the QEMUFile write impl to send the full
+ * data set we requested, so sanity check that.
+ */
+ if (ret != expect) {
+ qemu_file_set_error(f, ret < 0 ? ret : -EIO);
+ }
f->buf_index = 0;
f->iovcnt = 0;
- if (ret < 0) {
- qemu_file_set_error(f, ret);
- }
}
void ram_control_before_iterate(QEMUFile *f, uint64_t flags)
{
int ret = 0;
- if (f->ops->before_ram_iterate) {
- ret = f->ops->before_ram_iterate(f, f->opaque, flags, NULL);
+ if (f->hooks && f->hooks->before_ram_iterate) {
+ ret = f->hooks->before_ram_iterate(f, f->opaque, flags, NULL);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
{
int ret = 0;
- if (f->ops->after_ram_iterate) {
- ret = f->ops->after_ram_iterate(f, f->opaque, flags, NULL);
+ if (f->hooks && f->hooks->after_ram_iterate) {
+ ret = f->hooks->after_ram_iterate(f, f->opaque, flags, NULL);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
{
int ret = -EINVAL;
- if (f->ops->hook_ram_load) {
- ret = f->ops->hook_ram_load(f, f->opaque, flags, data);
+ if (f->hooks && f->hooks->hook_ram_load) {
+ ret = f->hooks->hook_ram_load(f, f->opaque, flags, data);
if (ret < 0) {
qemu_file_set_error(f, ret);
}
ram_addr_t offset, size_t size,
uint64_t *bytes_sent)
{
- if (f->ops->save_page) {
- int ret = f->ops->save_page(f, f->opaque, block_offset,
- offset, size, bytes_sent);
+ if (f->hooks && f->hooks->save_page) {
+ int ret = f->hooks->save_page(f, f->opaque, block_offset,
+ offset, size, bytes_sent);
if (ret != RAM_SAVE_CONTROL_DELAYED) {
if (bytes_sent && *bytes_sent > 0) {
return len;
}
-int qemu_get_fd(QEMUFile *f)
-{
- if (f->ops->get_fd) {
- return f->ops->get_fd(f->opaque);
- }
- return -1;
-}
-
void qemu_update_position(QEMUFile *f, size_t size)
{
f->pos += size;
return ret;
}
-static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size)
+static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size,
+ bool may_free)
{
/* check for adjacent buffer and coalesce them */
if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base +
- f->iov[f->iovcnt - 1].iov_len) {
+ f->iov[f->iovcnt - 1].iov_len &&
+ may_free == test_bit(f->iovcnt - 1, f->may_free))
+ {
f->iov[f->iovcnt - 1].iov_len += size;
} else {
+ if (may_free) {
+ set_bit(f->iovcnt, f->may_free);
+ }
f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
f->iov[f->iovcnt++].iov_len = size;
}
}
}
-void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size)
+void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
+ bool may_free)
{
- if (!f->ops->writev_buffer) {
- qemu_put_buffer(f, buf, size);
- return;
- }
-
if (f->last_error) {
return;
}
f->bytes_xfer += size;
- add_to_iovec(f, buf, size);
+ add_to_iovec(f, buf, size, may_free);
}
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size)
}
memcpy(f->buf + f->buf_index, buf, l);
f->bytes_xfer += l;
- if (f->ops->writev_buffer) {
- add_to_iovec(f, f->buf + f->buf_index, l);
- }
+ add_to_iovec(f, f->buf + f->buf_index, l, false);
f->buf_index += l;
if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f);
f->buf[f->buf_index] = v;
f->bytes_xfer++;
- if (f->ops->writev_buffer) {
- add_to_iovec(f, f->buf + f->buf_index, 1);
- }
+ add_to_iovec(f, f->buf + f->buf_index, 1, false);
f->buf_index++;
if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f);
return done;
}
+/*
+ * Read 'size' bytes of data from the file.
+ * 'size' can be larger than the internal buffer.
+ *
+ * The data:
+ * may be held on an internal buffer (in which case *buf is updated
+ * to point to it) that is valid until the next qemu_file operation.
+ * OR
+ * will be copied to the *buf that was passed in.
+ *
+ * The code tries to avoid the copy if possible.
+ *
+ * It will return size bytes unless there was an error, in which case it will
+ * return as many as it managed to read (assuming blocking fd's which
+ * all current QEMUFile are)
+ *
+ * Note: Since **buf may get changed, the caller should take care to
+ * keep a pointer to the original buffer if it needs to deallocate it.
+ */
+size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
+{
+ if (size < IO_BUF_SIZE) {
+ size_t res;
+ uint8_t *src;
+
+ res = qemu_peek_buffer(f, &src, size, 0);
+
+ if (res == size) {
+ qemu_file_skip(f, res);
+ *buf = src;
+ return res;
+ }
+ }
+
+ return qemu_get_buffer(f, *buf, size);
+}
+
/*
* Peeks a single byte from the buffer; this isn't guaranteed to work if
* offset leaves a gap after the previous read/peeked data.
int64_t ret = f->pos;
int i;
- if (f->ops->writev_buffer) {
- for (i = 0; i < f->iovcnt; i++) {
- ret += f->iov[i].iov_len;
- }
- } else {
- ret += f->buf_index;
+ for (i = 0; i < f->iovcnt; i++) {
+ ret += f->iov[i].iov_len;
}
return ret;
return v;
}
-/* compress size bytes of data start at p with specific compression
+/* Compress size bytes of data start at p with specific compression
* level and store the compressed data to the buffer of f.
+ *
+ * When f is not writable, return -1 if f has no space to save the
+ * compressed data.
+ * When f is wirtable and it has no space to save the compressed data,
+ * do fflush first, if f still has no space to save the compressed
+ * data, return -1.
*/
ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
if (blen < compressBound(size)) {
- return 0;
+ if (!qemu_file_is_writable(f)) {
+ return -1;
+ }
+ qemu_fflush(f);
+ blen = IO_BUF_SIZE - sizeof(int32_t);
+ if (blen < compressBound(size)) {
+ return -1;
+ }
}
if (compress2(f->buf + f->buf_index + sizeof(int32_t), (uLongf *)&blen,
(Bytef *)p, size, level) != Z_OK) {
return 0;
}
qemu_put_be32(f, blen);
+ if (f->ops->writev_buffer) {
+ add_to_iovec(f, f->buf + f->buf_index, blen, false);
+ }
f->buf_index += blen;
+ if (f->buf_index == IO_BUF_SIZE) {
+ qemu_fflush(f);
+ }
return blen + sizeof(int32_t);
}
len = f_src->buf_index;
qemu_put_buffer(f_des, f_src->buf, f_src->buf_index);
f_src->buf_index = 0;
+ f_src->iovcnt = 0;
}
return len;
}
return res == len ? res : 0;
}
+
+/*
+ * Set the blocking state of the QEMUFile.
+ * Note: On some transports the OS only keeps a single blocking state for
+ * both directions, and thus changing the blocking on the main
+ * QEMUFile can also affect the return path.
+ */
+void qemu_file_set_blocking(QEMUFile *f, bool block)
+{
+ if (f->ops->set_blocking) {
+ f->ops->set_blocking(f->opaque, block);
+ }
+}
projects / qemu.git / blobdiff