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-rw-r--r--qemu-file.c826
1 files changed, 826 insertions, 0 deletions
diff --git a/qemu-file.c b/qemu-file.c
new file mode 100644
index 0000000000..9473b674ba
--- /dev/null
+++ b/qemu-file.c
@@ -0,0 +1,826 @@
+#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"
+
+#define IO_BUF_SIZE 32768
+#define MAX_IOV_SIZE MIN(IOV_MAX, 64)
+
+struct QEMUFile {
+ const QEMUFileOps *ops;
+ 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];
+
+ struct iovec iov[MAX_IOV_SIZE];
+ unsigned int iovcnt;
+
+ int last_error;
+};
+
+typedef struct QEMUFileStdio {
+ FILE *stdio_file;
+ QEMUFile *file;
+} QEMUFileStdio;
+
+typedef struct QEMUFileSocket {
+ int fd;
+ QEMUFile *file;
+} QEMUFileSocket;
+
+static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
+ int64_t pos)
+{
+ QEMUFileSocket *s = opaque;
+ ssize_t len;
+ ssize_t size = iov_size(iov, iovcnt);
+
+ len = iov_send(s->fd, iov, iovcnt, 0, size);
+ if (len < size) {
+ len = -socket_error();
+ }
+ return len;
+}
+
+static int socket_get_fd(void *opaque)
+{
+ QEMUFileSocket *s = opaque;
+
+ return s->fd;
+}
+
+static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
+{
+ QEMUFileSocket *s = opaque;
+ ssize_t len;
+
+ for (;;) {
+ len = qemu_recv(s->fd, buf, size, 0);
+ if (len != -1) {
+ break;
+ }
+ if (socket_error() == EAGAIN) {
+ yield_until_fd_readable(s->fd);
+ } else if (socket_error() != EINTR) {
+ break;
+ }
+ }
+
+ if (len == -1) {
+ len = -socket_error();
+ }
+ return len;
+}
+
+static int socket_close(void *opaque)
+{
+ QEMUFileSocket *s = opaque;
+ closesocket(s->fd);
+ g_free(s);
+ return 0;
+}
+
+static int stdio_get_fd(void *opaque)
+{
+ QEMUFileStdio *s = opaque;
+
+ return fileno(s->stdio_file);
+}
+
+static int stdio_put_buffer(void *opaque, const uint8_t *buf, int64_t pos,
+ int size)
+{
+ QEMUFileStdio *s = opaque;
+ return fwrite(buf, 1, size, s->stdio_file);
+}
+
+static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
+{
+ QEMUFileStdio *s = opaque;
+ FILE *fp = s->stdio_file;
+ int bytes;
+
+ for (;;) {
+ clearerr(fp);
+ bytes = fread(buf, 1, size, fp);
+ if (bytes != 0 || !ferror(fp)) {
+ break;
+ }
+ if (errno == EAGAIN) {
+ yield_until_fd_readable(fileno(fp));
+ } else if (errno != EINTR) {
+ break;
+ }
+ }
+ return bytes;
+}
+
+static int stdio_pclose(void *opaque)
+{
+ QEMUFileStdio *s = opaque;
+ int ret;
+ ret = pclose(s->stdio_file);
+ if (ret == -1) {
+ ret = -errno;
+ } else if (!WIFEXITED(ret) || WEXITSTATUS(ret) != 0) {
+ /* close succeeded, but non-zero exit code: */
+ ret = -EIO; /* fake errno value */
+ }
+ g_free(s);
+ return ret;
+}
+
+static int stdio_fclose(void *opaque)
+{
+ QEMUFileStdio *s = opaque;
+ int ret = 0;
+
+ if (s->file->ops->put_buffer || s->file->ops->writev_buffer) {
+ int fd = fileno(s->stdio_file);
+ struct stat st;
+
+ ret = fstat(fd, &st);
+ if (ret == 0 && S_ISREG(st.st_mode)) {
+ /*
+ * If the file handle is a regular file make sure the
+ * data is flushed to disk before signaling success.
+ */
+ ret = fsync(fd);
+ if (ret != 0) {
+ ret = -errno;
+ return ret;
+ }
+ }
+ }
+ if (fclose(s->stdio_file) == EOF) {
+ ret = -errno;
+ }
+ g_free(s);
+ return ret;
+}
+
+static const QEMUFileOps stdio_pipe_read_ops = {
+ .get_fd = stdio_get_fd,
+ .get_buffer = stdio_get_buffer,
+ .close = stdio_pclose
+};
+
+static const QEMUFileOps stdio_pipe_write_ops = {
+ .get_fd = stdio_get_fd,
+ .put_buffer = stdio_put_buffer,
+ .close = stdio_pclose
+};
+
+QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
+{
+ FILE *stdio_file;
+ QEMUFileStdio *s;
+
+ if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
+ fprintf(stderr, "qemu_popen: Argument validity check failed\n");
+ return NULL;
+ }
+
+ stdio_file = popen(command, mode);
+ if (stdio_file == NULL) {
+ return NULL;
+ }
+
+ s = g_malloc0(sizeof(QEMUFileStdio));
+
+ s->stdio_file = stdio_file;
+
+ if (mode[0] == 'r') {
+ s->file = qemu_fopen_ops(s, &stdio_pipe_read_ops);
+ } else {
+ s->file = qemu_fopen_ops(s, &stdio_pipe_write_ops);
+ }
+ return s->file;
+}
+
+static const QEMUFileOps stdio_file_read_ops = {
+ .get_fd = stdio_get_fd,
+ .get_buffer = stdio_get_buffer,
+ .close = stdio_fclose
+};
+
+static const QEMUFileOps stdio_file_write_ops = {
+ .get_fd = stdio_get_fd,
+ .put_buffer = stdio_put_buffer,
+ .close = stdio_fclose
+};
+
+static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
+ int64_t pos)
+{
+ QEMUFileSocket *s = opaque;
+ ssize_t len, offset;
+ ssize_t size = iov_size(iov, iovcnt);
+ ssize_t total = 0;
+
+ assert(iovcnt > 0);
+ offset = 0;
+ while (size > 0) {
+ /* Find the next start position; skip all full-sized vector elements */
+ while (offset >= iov[0].iov_len) {
+ offset -= iov[0].iov_len;
+ iov++, iovcnt--;
+ }
+
+ /* skip `offset' bytes from the (now) first element, undo it on exit */
+ assert(iovcnt > 0);
+ iov[0].iov_base += offset;
+ iov[0].iov_len -= offset;
+
+ do {
+ len = writev(s->fd, iov, iovcnt);
+ } while (len == -1 && errno == EINTR);
+ if (len == -1) {
+ return -errno;
+ }
+
+ /* Undo the changes above */
+ iov[0].iov_base -= offset;
+ iov[0].iov_len += offset;
+
+ /* Prepare for the next iteration */
+ offset += len;
+ total += len;
+ size -= len;
+ }
+
+ return total;
+}
+
+static int unix_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
+{
+ QEMUFileSocket *s = opaque;
+ ssize_t len;
+
+ for (;;) {
+ len = read(s->fd, buf, size);
+ if (len != -1) {
+ break;
+ }
+ if (errno == EAGAIN) {
+ yield_until_fd_readable(s->fd);
+ } else if (errno != EINTR) {
+ break;
+ }
+ }
+
+ if (len == -1) {
+ len = -errno;
+ }
+ return len;
+}
+
+static int unix_close(void *opaque)
+{
+ QEMUFileSocket *s = opaque;
+ close(s->fd);
+ g_free(s);
+ return 0;
+}
+
+static const QEMUFileOps unix_read_ops = {
+ .get_fd = socket_get_fd,
+ .get_buffer = unix_get_buffer,
+ .close = unix_close
+};
+
+static const QEMUFileOps unix_write_ops = {
+ .get_fd = socket_get_fd,
+ .writev_buffer = unix_writev_buffer,
+ .close = unix_close
+};
+
+QEMUFile *qemu_fdopen(int fd, const char *mode)
+{
+ QEMUFileSocket *s;
+
+ if (mode == NULL ||
+ (mode[0] != 'r' && mode[0] != 'w') ||
+ mode[1] != 'b' || mode[2] != 0) {
+ fprintf(stderr, "qemu_fdopen: Argument validity check failed\n");
+ return NULL;
+ }
+
+ s = g_malloc0(sizeof(QEMUFileSocket));
+ s->fd = fd;
+
+ if (mode[0] == 'r') {
+ s->file = qemu_fopen_ops(s, &unix_read_ops);
+ } else {
+ s->file = qemu_fopen_ops(s, &unix_write_ops);
+ }
+ return s->file;
+}
+
+static const QEMUFileOps socket_read_ops = {
+ .get_fd = socket_get_fd,
+ .get_buffer = socket_get_buffer,
+ .close = socket_close
+};
+
+static const QEMUFileOps socket_write_ops = {
+ .get_fd = socket_get_fd,
+ .writev_buffer = socket_writev_buffer,
+ .close = socket_close
+};
+
+bool qemu_file_mode_is_not_valid(const char *mode)
+{
+ if (mode == NULL ||
+ (mode[0] != 'r' && mode[0] != 'w') ||
+ mode[1] != 'b' || mode[2] != 0) {
+ fprintf(stderr, "qemu_fopen: Argument validity check failed\n");
+ return true;
+ }
+
+ return false;
+}
+
+QEMUFile *qemu_fopen_socket(int fd, const char *mode)
+{
+ QEMUFileSocket *s;
+
+ if (qemu_file_mode_is_not_valid(mode)) {
+ return NULL;
+ }
+
+ s = g_malloc0(sizeof(QEMUFileSocket));
+ s->fd = fd;
+ if (mode[0] == 'w') {
+ qemu_set_block(s->fd);
+ s->file = qemu_fopen_ops(s, &socket_write_ops);
+ } else {
+ s->file = qemu_fopen_ops(s, &socket_read_ops);
+ }
+ return s->file;
+}
+
+QEMUFile *qemu_fopen(const char *filename, const char *mode)
+{
+ QEMUFileStdio *s;
+
+ if (qemu_file_mode_is_not_valid(mode)) {
+ return NULL;
+ }
+
+ s = g_malloc0(sizeof(QEMUFileStdio));
+
+ s->stdio_file = fopen(filename, mode);
+ if (!s->stdio_file) {
+ goto fail;
+ }
+
+ if (mode[0] == 'w') {
+ s->file = qemu_fopen_ops(s, &stdio_file_write_ops);
+ } else {
+ s->file = qemu_fopen_ops(s, &stdio_file_read_ops);
+ }
+ return s->file;
+fail:
+ g_free(s);
+ return NULL;
+}
+
+QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
+{
+ QEMUFile *f;
+
+ f = g_malloc0(sizeof(QEMUFile));
+
+ f->opaque = opaque;
+ f->ops = ops;
+ return f;
+}
+
+/*
+ * Get last error for stream f
+ *
+ * Return negative error value if there has been an error on previous
+ * operations, return 0 if no error happened.
+ *
+ */
+int qemu_file_get_error(QEMUFile *f)
+{
+ return f->last_error;
+}
+
+void qemu_file_set_error(QEMUFile *f, int ret)
+{
+ if (f->last_error == 0) {
+ f->last_error = ret;
+ }
+}
+
+static inline bool qemu_file_is_writable(QEMUFile *f)
+{
+ return f->ops->writev_buffer || f->ops->put_buffer;
+}
+
+/**
+ * Flushes QEMUFile buffer
+ *
+ * If there is writev_buffer QEMUFileOps it uses it otherwise uses
+ * put_buffer ops.
+ */
+void qemu_fflush(QEMUFile *f)
+{
+ ssize_t ret = 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 (ret >= 0) {
+ f->pos += ret;
+ }
+ 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);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ }
+ }
+}
+
+void ram_control_after_iterate(QEMUFile *f, uint64_t flags)
+{
+ int ret = 0;
+
+ if (f->ops->after_ram_iterate) {
+ ret = f->ops->after_ram_iterate(f, f->opaque, flags);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ }
+ }
+}
+
+void ram_control_load_hook(QEMUFile *f, uint64_t flags)
+{
+ int ret = -EINVAL;
+
+ if (f->ops->hook_ram_load) {
+ ret = f->ops->hook_ram_load(f, f->opaque, flags);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ }
+ } else {
+ qemu_file_set_error(f, ret);
+ }
+}
+
+size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
+ ram_addr_t offset, size_t size, int *bytes_sent)
+{
+ if (f->ops->save_page) {
+ int ret = f->ops->save_page(f, f->opaque, block_offset,
+ offset, size, bytes_sent);
+
+ if (ret != RAM_SAVE_CONTROL_DELAYED) {
+ if (bytes_sent && *bytes_sent > 0) {
+ qemu_update_position(f, *bytes_sent);
+ } else if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ }
+ }
+
+ return ret;
+ }
+
+ return RAM_SAVE_CONTROL_NOT_SUPP;
+}
+
+static void qemu_fill_buffer(QEMUFile *f)
+{
+ int len;
+ int pending;
+
+ assert(!qemu_file_is_writable(f));
+
+ pending = f->buf_size - f->buf_index;
+ if (pending > 0) {
+ memmove(f->buf, f->buf + f->buf_index, pending);
+ }
+ f->buf_index = 0;
+ f->buf_size = pending;
+
+ len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos,
+ IO_BUF_SIZE - pending);
+ if (len > 0) {
+ f->buf_size += len;
+ f->pos += len;
+ } else if (len == 0) {
+ qemu_file_set_error(f, -EIO);
+ } else if (len != -EAGAIN) {
+ qemu_file_set_error(f, 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;
+}
+
+/** Closes the file
+ *
+ * Returns negative error value if any error happened on previous operations or
+ * while closing the file. Returns 0 or positive number on success.
+ *
+ * The meaning of return value on success depends on the specific backend
+ * being used.
+ */
+int qemu_fclose(QEMUFile *f)
+{
+ int ret;
+ qemu_fflush(f);
+ ret = qemu_file_get_error(f);
+
+ if (f->ops->close) {
+ int ret2 = f->ops->close(f->opaque);
+ if (ret >= 0) {
+ ret = ret2;
+ }
+ }
+ /* If any error was spotted before closing, we should report it
+ * instead of the close() return value.
+ */
+ if (f->last_error) {
+ ret = f->last_error;
+ }
+ g_free(f);
+ return ret;
+}
+
+static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size)
+{
+ /* 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 += size;
+ } else {
+ f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
+ f->iov[f->iovcnt++].iov_len = size;
+ }
+
+ if (f->iovcnt >= MAX_IOV_SIZE) {
+ qemu_fflush(f);
+ }
+}
+
+void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size)
+{
+ 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);
+}
+
+void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
+{
+ int l;
+
+ if (f->last_error) {
+ return;
+ }
+
+ while (size > 0) {
+ l = IO_BUF_SIZE - f->buf_index;
+ if (l > size) {
+ l = 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);
+ }
+ f->buf_index += l;
+ if (f->buf_index == IO_BUF_SIZE) {
+ qemu_fflush(f);
+ }
+ if (qemu_file_get_error(f)) {
+ break;
+ }
+ buf += l;
+ size -= l;
+ }
+}
+
+void qemu_put_byte(QEMUFile *f, int v)
+{
+ if (f->last_error) {
+ return;
+ }
+
+ f->buf[f->buf_index] = v;
+ f->bytes_xfer++;
+ if (f->ops->writev_buffer) {
+ add_to_iovec(f, f->buf + f->buf_index, 1);
+ }
+ f->buf_index++;
+ if (f->buf_index == IO_BUF_SIZE) {
+ qemu_fflush(f);
+ }
+}
+
+void qemu_file_skip(QEMUFile *f, int size)
+{
+ if (f->buf_index + size <= f->buf_size) {
+ f->buf_index += size;
+ }
+}
+
+int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)
+{
+ int pending;
+ int index;
+
+ assert(!qemu_file_is_writable(f));
+
+ index = f->buf_index + offset;
+ pending = f->buf_size - index;
+ if (pending < size) {
+ qemu_fill_buffer(f);
+ index = f->buf_index + offset;
+ pending = f->buf_size - index;
+ }
+
+ if (pending <= 0) {
+ return 0;
+ }
+ if (size > pending) {
+ size = pending;
+ }
+
+ memcpy(buf, f->buf + index, size);
+ return size;
+}
+
+int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size)
+{
+ int pending = size;
+ int done = 0;
+
+ while (pending > 0) {
+ int res;
+
+ res = qemu_peek_buffer(f, buf, pending, 0);
+ if (res == 0) {
+ return done;
+ }
+ qemu_file_skip(f, res);
+ buf += res;
+ pending -= res;
+ done += res;
+ }
+ return done;
+}
+
+int qemu_peek_byte(QEMUFile *f, int offset)
+{
+ int index = f->buf_index + offset;
+
+ assert(!qemu_file_is_writable(f));
+
+ if (index >= f->buf_size) {
+ qemu_fill_buffer(f);
+ index = f->buf_index + offset;
+ if (index >= f->buf_size) {
+ return 0;
+ }
+ }
+ return f->buf[index];
+}
+
+int qemu_get_byte(QEMUFile *f)
+{
+ int result;
+
+ result = qemu_peek_byte(f, 0);
+ qemu_file_skip(f, 1);
+ return result;
+}
+
+int64_t qemu_ftell(QEMUFile *f)
+{
+ qemu_fflush(f);
+ return f->pos;
+}
+
+int qemu_file_rate_limit(QEMUFile *f)
+{
+ if (qemu_file_get_error(f)) {
+ return 1;
+ }
+ if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) {
+ return 1;
+ }
+ return 0;
+}
+
+int64_t qemu_file_get_rate_limit(QEMUFile *f)
+{
+ return f->xfer_limit;
+}
+
+void qemu_file_set_rate_limit(QEMUFile *f, int64_t limit)
+{
+ f->xfer_limit = limit;
+}
+
+void qemu_file_reset_rate_limit(QEMUFile *f)
+{
+ f->bytes_xfer = 0;
+}
+
+void qemu_put_be16(QEMUFile *f, unsigned int v)
+{
+ qemu_put_byte(f, v >> 8);
+ qemu_put_byte(f, v);
+}
+
+void qemu_put_be32(QEMUFile *f, unsigned int v)
+{
+ qemu_put_byte(f, v >> 24);
+ qemu_put_byte(f, v >> 16);
+ qemu_put_byte(f, v >> 8);
+ qemu_put_byte(f, v);
+}
+
+void qemu_put_be64(QEMUFile *f, uint64_t v)
+{
+ qemu_put_be32(f, v >> 32);
+ qemu_put_be32(f, v);
+}
+
+unsigned int qemu_get_be16(QEMUFile *f)
+{
+ unsigned int v;
+ v = qemu_get_byte(f) << 8;
+ v |= qemu_get_byte(f);
+ return v;
+}
+
+unsigned int qemu_get_be32(QEMUFile *f)
+{
+ unsigned int v;
+ v = qemu_get_byte(f) << 24;
+ v |= qemu_get_byte(f) << 16;
+ v |= qemu_get_byte(f) << 8;
+ v |= qemu_get_byte(f);
+ return v;
+}
+
+uint64_t qemu_get_be64(QEMUFile *f)
+{
+ uint64_t v;
+ v = (uint64_t)qemu_get_be32(f) << 32;
+ v |= qemu_get_be32(f);
+ return v;
+}
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-23 21:22:36 +0000