Re: [Qemu-devel] [PATCH V4 4/5] exec, memory: Call to xen_modified_memory.

[Anthony PERARD <anthony.perard@citrix.com>]

On 10/02/2012 11:25 AM, Avi Kivity wrote:
> On 10/01/2012 12:36 PM, Stefano Stabellini wrote:
>> On Thu, 27 Sep 2012, Anthony PERARD wrote:
>>> This patch add some calls to xen_modified_memory to notify Xen about
dirtybits
>>> during migration.
>>>
>>> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
>>
>> If I am not mistaken, this is the last patch that needs reviewing.
>> Avi, are you OK with it?
>>
>>
>>
>>>  exec.c   | 1 +
>>>  memory.c | 2 ++
>>>  2 files changed, 3 insertions(+)
>>>
>>> diff --git a/exec.c b/exec.c
>>> index 366684c..1114a09 100644
>>> --- a/exec.c
>>> +++ b/exec.c
>>> @@ -3427,6 +3427,7 @@ static void
invalidate_and_set_dirty(target_phys_addr_t addr,
>>>          /* set dirty bit */
>>>          cpu_physical_memory_set_dirty_flags(addr, (0xff &
~CODE_DIRTY_FLAG));
>>>      }
>>> +    xen_modified_memory(addr, length);
>>>  }
>>>
>>>  void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
>>> diff --git a/memory.c b/memory.c
>>> index 4f3ade0..015c544 100644
>>> --- a/memory.c
>>> +++ b/memory.c
>>> @@ -19,6 +19,7 @@
>>>  #include "bitops.h"
>>>  #include "kvm.h"
>>>  #include <assert.h>
>>> +#include "hw/xen.h"
>>>
>>>  #define WANT_EXEC_OBSOLETE
>>>  #include "exec-obsolete.h"
>>> @@ -1077,6 +1078,7 @@ void memory_region_set_dirty(MemoryRegion *mr,
target_phys_addr_t addr,
>>>                               target_phys_addr_t size)
>>>  {
>>>      assert(mr->terminates);
>>> +    xen_modified_memory(mr->ram_addr + addr, size);
>>>      return cpu_physical_memory_set_dirty_range(mr->ram_addr + addr,
size, -1);
>>>  }
>
> I would prefer this bit pushed into cpu_physical_set_dirty_range().

Ok, I will call the function from cpu_physical_memory_set_dirty_range()
instead of from memory_region_set_dirty.

> Possibly the first bit too?

But the call from invalidate_and_set_dirty, I can not remove it because
it does not work.  The xen function must be called without condition as
xen and qemu does not maintained the same dirtymap.

-- 
Anthony PERARD