Re: [PATCH RFC v2 6/6] KVM: introduce a new API for getting dirty bitmaps

On 20.04.2010, at 13:03, Takuya Yoshikawa wrote:

> We can now export the addree of the bitmap created by do_mmap()
> to user space. For the sake of this, we introduce a new API:
> 
>  KVM_SWITCH_DIRTY_LOG: application can use this to trigger the
>  switch of the bitmaps and get the address of the bitmap which
>  has been used until now. This reduces the copy of the dirty
>  bitmap from the kernel.
> 
> Signed-off-by: Takuya Yoshikawa <[email protected]>
> Cc: Fernando Luis Vazquez Cao <[email protected]>
> ---
> Documentation/kvm/api.txt |   23 +++++++++++++++++++++++
> arch/ia64/kvm/kvm-ia64.c  |   19 ++++++++++++++-----
> arch/powerpc/kvm/book3s.c |   19 ++++++++++++++-----
> arch/x86/kvm/x86.c        |   32 ++++++++++++++++++++++++++------
> include/linux/kvm.h       |    6 ++++--
> include/linux/kvm_host.h  |    7 ++++---
> virt/kvm/kvm_main.c       |   41 ++++++++++++++++++++++++++++++++++++-----
> 7 files changed, 121 insertions(+), 26 deletions(-)
> 

[...]

> diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> index 23ea022..9fa6f1e 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -12,7 +12,7 @@
> #include <linux/ioctl.h>
> #include <asm/kvm.h>
> 
> -#define KVM_API_VERSION 12
> +#define KVM_API_VERSION 13

Is there a way to keep both interfaces around for some time at least? I'd prefer the API version not to change if not _really_ necessary.

To enable the new dirty mapping you could for example use KVM_CAP_ENABLE_CAP :-).


Alex