Re: [PATCH 2/2] KVM: Document KVM_SET_TSS_ADDR

[Pekka Enberg <penberg@cs.helsinki.fi>]

Hi Avi,

Avi Kivity kirjoitti:
> Signed-off-by: Avi Kivity <avi@redhat.com>
> ---
>  Documentation/kvm/api.txt |   16 ++++++++++++++++
>  1 files changed, 16 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
> index 22af28a..8f45099 100644
> --- a/Documentation/kvm/api.txt
> +++ b/Documentation/kvm/api.txt
> @@ -793,6 +793,22 @@ is madvise(MADV_DROP).
>  
>  It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl.
>  
> +4.35 KVM_SET_TSS_ADDR
> +
> +Capability: KVM_CAP_SET_TSS_ADDR
> +Architectures: x86
> +Type: vm ioctl
> +Parameters: unsigned long tss_address (in)
> +Returns: 0 on success, -1 on error
> +
> +This ioctl defines the physical address of a three-page region in the guest
> +physical address space.  The region must be within the first 4GB of the
> +guest physical address space and must not conflict with any memory slot
> +or any mmio address.  The guest may malfunction if it accesses this memory
> +region.
> +
> +This ioctl is required on Intel-based hosts.

I don't quite understand what it's _used for_ from the above 
description. I assume it's about task state segment...?

>  5. The kvm_run structure
>  
>  Application code obtains a pointer to the kvm_run structure by