Re: [Qemu-devel] [PATCH v5 09/45] Migration commands

[Dr. David Alan Gilbert]

* David Gibson (address@hidden) wrote:
> On Wed, Feb 25, 2015 at 04:51:32PM +0000, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> > 
> > Create QEMU_VM_COMMAND section type for sending commands from
> > source to destination.  These commands are not intended to convey
> > guest state but to control the migration process.
> > 
> > For use in postcopy.
> > 
> > Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> 
> [snip]
> > +/* Send a 'QEMU_VM_COMMAND' type element with the command
> > + * and associated data.
> > + */
> > +void qemu_savevm_command_send(QEMUFile *f,
> > +                              enum qemu_vm_cmd command,
> > +                              uint16_t len,
> > +                              uint8_t *data)
> > +{
> > +    uint32_t tmp = (uint16_t)command;
> 
> Erm.. cast to u16, assign to u32, then send as u16?  What's up with
> that?

Hmm yes, that is insane;  now changed to:

+void qemu_savevm_command_send(QEMUFile *f,
+                              enum qemu_vm_cmd command,
+                              uint16_t len,
+                              uint8_t *data)
+{
+    qemu_put_byte(f, QEMU_VM_COMMAND);
+    qemu_put_be16(f, (uint16_t)command);
+    qemu_put_be16(f, len);
+    if (len) {
+        qemu_put_buffer(f, data, len);
+    }
+    qemu_fflush(f);
+}

Thanks,

Dave

> 
> > +    qemu_put_byte(f, QEMU_VM_COMMAND);
> > +    qemu_put_be16(f, tmp);
> > +    qemu_put_be16(f, len);
> > +    if (len) {
> > +        qemu_put_buffer(f, data, len);
> > +    }
> > +    qemu_fflush(f);
> > +}
> > +
> 
> -- 
> David Gibson                  | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au        | minimalist, thank you.  NOT _the_ 
> _other_
>                               | _way_ _around_!
> http://www.ozlabs.org/~dgibson


--
Dr. David Alan Gilbert / address@hidden / Manchester, UK