Re: [PATCH 1/2] Nested VMX: update nested paging mode on vmexit

["Egger, Christoph" <chegger@amazon.de>]

On 12.02.14 03:08, Yang Zhang wrote:
> From: Yang Zhang <yang.z.zhang@Intel.com>
> 
> Since SVM and VMX use different mechanism to emulate the virtual-vmentry
> and virtual-vmexit, it's hard to update the nested paging mode correctly in
> common code. So we need to update the nested paging mode in their respective
> code path.
> SVM already updates the nested paging mode on vmexit. This patch adds the same
> logic in VMX side.
> 
> Previous discussion is here:
> http://lists.xen.org/archives/html/xen-devel/2013-12/msg01759.html
> 
> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Christoph Egger <chegger@amazon.de>

> ---
>  xen/arch/x86/hvm/vmx/vmx.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
> index f6409d6..baf3040 100644
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -2541,6 +2541,7 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
>      vcpu_nestedhvm(v).nv_vmswitch_in_progress = 0;
>      if ( nestedhvm_vcpu_in_guestmode(v) )
>      {
> +        paging_update_nestedmode(v);
>          if ( nvmx_n2_vmexit_handler(regs, exit_reason) )
>              goto out;
>      }
>