On 11/26/2013 07:31 PM, Paolo Bonzini wrote:
Il 21/11/2013 10:11, Lei Li ha scritto:
+ /*
+ * recvmsg is called here to catch the control message for
+ * the exchange of PIPE file descriptor until it is received.
+ */
+ len = recvmsg(s->sockfd, &msg, 0);
+ if (len != -1) {
+ if (unix_msgfd_lookup(s, &msg) > 0) {
+ pipefd_passed = 1;
+ /*
+ * Do not count one byte taken by the PIPE file
+ * descriptor.
+ */
+ len--;
I think adding a byte in the middle of the stream is not reliable.
Rather, you should transmit the socket always at the same place, for
example in the first call of qemu_local_save_ram, after it has written
the 64-bit field.
I guess 'transmit the socket' you mean transmit the fd?
Sorry that I am quite understand your suggestion here.. Do you
mean that send_pipefd in the first call of qemu_local_save_ram
after it has written the 64-bit field? In this way, get rid of
qemu_local_send_pipefd?
Currently, the fd control message is sent at the end of the stream
in ram_save_setup stage, followed by the ram page. The control
message of fd is always at the same place.
The matching code in qemu_local_ram_load will be like this:
static int qemu_local_ram_load(QEMUFile *f, void *opaque,
uint64_t flags)
{
QEMUFileLocal *s = opaque;
ram_addr_t addr;
struct iovec iov;
ssize_t ret = -EINVAL;
if (!s->pipefd_received) {
/*
* send_pipefd was called at this point, and it wrote one byte
* to the stream.
*/
qemu_get_byte(s);
s->pipefd_received = true;
}
if (pipefd_passed) {
...
}
return -EINVAL;
}
Also, please move pipefd_passed within QEMUFileLocal.
Thanks,
Paolo
--
Lei
