Merge remote-tracking branch 'quintela/migration.next' into staging

# By Paolo Bonzini
# Via Juan Quintela
* quintela/migration.next:
  migration: simplify writev vs. non-writev logic
  migration: drop is_write complications
  migration: use a single I/O operation when writev_buffer is not defined
  migration: set f->is_write and flush in add_to_iovec

Message-id: 1365512961-15623-1-git-send-email-quintela@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2013-04-15 07:46:39 -05:00
commit b25ce104a2
1 changed files with 43 additions and 63 deletions

View File

@ -119,7 +119,6 @@ void qemu_announce_self(void)
struct QEMUFile { struct QEMUFile {
const QEMUFileOps *ops; const QEMUFileOps *ops;
void *opaque; void *opaque;
int is_write;
int64_t bytes_xfer; int64_t bytes_xfer;
int64_t xfer_limit; int64_t xfer_limit;
@ -500,7 +499,6 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
f->opaque = opaque; f->opaque = opaque;
f->ops = ops; f->ops = ops;
f->is_write = 0;
return f; return f;
} }
@ -516,6 +514,11 @@ static void qemu_file_set_error(QEMUFile *f, int ret)
} }
} }
static inline bool qemu_file_is_writable(QEMUFile *f)
{
return f->ops->writev_buffer || f->ops->put_buffer;
}
/** /**
* Flushes QEMUFile buffer * Flushes QEMUFile buffer
* *
@ -525,30 +528,25 @@ static void qemu_file_set_error(QEMUFile *f, int ret)
static void qemu_fflush(QEMUFile *f) static void qemu_fflush(QEMUFile *f)
{ {
ssize_t ret = 0; ssize_t ret = 0;
int i = 0;
if (!f->ops->writev_buffer && !f->ops->put_buffer) { if (!qemu_file_is_writable(f)) {
return; return;
} }
if (f->is_write && f->iovcnt > 0) {
if (f->ops->writev_buffer) { if (f->ops->writev_buffer) {
if (f->iovcnt > 0) {
ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt); ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt);
if (ret >= 0) {
f->pos += ret;
} }
} else { } else {
for (i = 0; i < f->iovcnt && ret >= 0; i++) { if (f->buf_index > 0) {
ret = f->ops->put_buffer(f->opaque, f->iov[i].iov_base, f->pos, ret = f->ops->put_buffer(f->opaque, f->buf, f->pos, f->buf_index);
f->iov[i].iov_len); }
}
if (ret >= 0) { if (ret >= 0) {
f->pos += ret; f->pos += ret;
} }
}
}
f->buf_index = 0; f->buf_index = 0;
f->iovcnt = 0; f->iovcnt = 0;
}
if (ret < 0) { if (ret < 0) {
qemu_file_set_error(f, ret); qemu_file_set_error(f, ret);
} }
@ -559,11 +557,7 @@ static void qemu_fill_buffer(QEMUFile *f)
int len; int len;
int pending; int pending;
if (!f->ops->get_buffer) assert(!qemu_file_is_writable(f));
return;
if (f->is_write)
abort();
pending = f->buf_size - f->buf_index; pending = f->buf_size - f->buf_index;
if (pending > 0) { if (pending > 0) {
@ -631,28 +625,25 @@ static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size)
f->iov[f->iovcnt].iov_base = (uint8_t *)buf; f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
f->iov[f->iovcnt++].iov_len = size; 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) 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) { if (f->last_error) {
return; return;
} }
if (f->is_write == 0 && f->buf_index > 0) {
fprintf(stderr,
"Attempted to write to buffer while read buffer is not empty\n");
abort();
}
add_to_iovec(f, buf, size);
f->is_write = 1;
f->bytes_xfer += size; f->bytes_xfer += size;
add_to_iovec(f, buf, size);
if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
qemu_fflush(f);
}
} }
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size) void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
@ -663,20 +654,19 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
return; return;
} }
if (f->is_write == 0 && f->buf_index > 0) {
fprintf(stderr,
"Attempted to write to buffer while read buffer is not empty\n");
abort();
}
while (size > 0) { while (size > 0) {
l = IO_BUF_SIZE - f->buf_index; l = IO_BUF_SIZE - f->buf_index;
if (l > size) if (l > size)
l = size; l = size;
memcpy(f->buf + f->buf_index, buf, l); memcpy(f->buf + f->buf_index, buf, l);
f->is_write = 1; f->bytes_xfer += size;
if (f->ops->writev_buffer) {
add_to_iovec(f, f->buf + f->buf_index, l);
}
f->buf_index += l; f->buf_index += l;
qemu_put_buffer_async(f, f->buf + (f->buf_index - l), l); if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f);
}
if (qemu_file_get_error(f)) { if (qemu_file_get_error(f)) {
break; break;
} }
@ -691,19 +681,13 @@ void qemu_put_byte(QEMUFile *f, int v)
return; return;
} }
if (f->is_write == 0 && f->buf_index > 0) { f->buf[f->buf_index] = v;
fprintf(stderr,
"Attempted to write to buffer while read buffer is not empty\n");
abort();
}
f->buf[f->buf_index++] = v;
f->is_write = 1;
f->bytes_xfer++; f->bytes_xfer++;
if (f->ops->writev_buffer) {
add_to_iovec(f, f->buf + (f->buf_index - 1), 1); add_to_iovec(f, f->buf + f->buf_index, 1);
}
if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { f->buf_index++;
if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f); qemu_fflush(f);
} }
} }
@ -720,9 +704,7 @@ static int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)
int pending; int pending;
int index; int index;
if (f->is_write) { assert(!qemu_file_is_writable(f));
abort();
}
index = f->buf_index + offset; index = f->buf_index + offset;
pending = f->buf_size - index; pending = f->buf_size - index;
@ -767,9 +749,7 @@ static int qemu_peek_byte(QEMUFile *f, int offset)
{ {
int index = f->buf_index + offset; int index = f->buf_index + offset;
if (f->is_write) { assert(!qemu_file_is_writable(f));
abort();
}
if (index >= f->buf_size) { if (index >= f->buf_size) {
qemu_fill_buffer(f); qemu_fill_buffer(f);