Hi Stefan, Nearly want I want... but I am mapping physical pages to virtual memory - therefore the last parameter of l4_task_map is the target virtual address. This leaves no place for the L4_MAP_ITEM_GRANT flag.

Daniel

On 03/28/2012 02:08 AM, Stefan Kalkowski wrote:

Hi Daniel,

as far as I understood you correctly, you just have to use the L4_ITEM_MAP_GRANT flag. It will make sure that the entries from the originator task are revocated, e.g.:

l4_task_map(dst_task, src_task, snd_fpage,
            cap | L4_ITEM_MAP | L4_MAP_ITEM_GRANT);

I hope this is what you were looking for.

Regards Stefan

On 28.03.2012 02:22, Daniel Waddington wrote:

...

Hi,

I am using l4_task_map to map flex pages to a child task. What I would like to do is grant a flex page to a child and remove the mapping from the parent. How do I do this? I have tried using l4_map_obj_control(0,1) for mr[3] on the task map call but this does not seem to help.

Thanks in advance, Daniel

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Yes I can confirm that this (appears) to work.

Thanks Daniel

On 03/30/2012 01:47 AM, Christian Helmuth wrote:

Hi,

On Wed, Mar 28, 2012 at 09:04:16AM -0700, Daniel Waddington wrote:

...

Nearly want I want... but I am mapping physical pages to virtual memory - therefore the last parameter of l4_task_map is the target virtual address. This leaves no place for the L4_MAP_ITEM_GRANT flag.

Did you test it? I think it should also work for memory mappings since the lower 12 bits of virtual-memory addresses are not significant for the snd_base parameter. The sources in

kernel/fiasco/src/kern/map_util-mem.cpp:54 and kernel/fiasco/src/abi/l4_msg_item.cpp:161

hint this behavior.

Greets