Re: [Xen-devel] [PATCH 5/5] hvm_complete_assist_req: Tell caller we failed to send

[Paul Durrant <Paul.Durrant@xxxxxxxxxx>]

> -----Original Message-----
> From: Don Slutz [mailto:dslutz@xxxxxxxxxxx]
> Sent: 30 January 2015 00:53
> To: xen-devel@xxxxxxxxxxxxx
> Cc: Andrew Cooper; George Dunlap; Ian Campbell; Ian Jackson; Jan Beulich;
> Keir (Xen.org); Stefano Stabellini; Wei Liu; Paul Durrant; Don Slutz
> Subject: [PATCH 5/5] hvm_complete_assist_req: Tell caller we failed to send
> 
> This saves a VMENTRY and a VMEXIT since we not longer retry the
> ioport read.
> 
> hvmemul_do_io() will retry in order to complete an ioport read when
> hvm_send_assist_req() is successful.
> 
> Signed-off-by: Don Slutz <dslutz@xxxxxxxxxxx>
> ---
>  xen/arch/x86/hvm/hvm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
> index 6f7b407..bad410e 100644
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -2599,7 +2599,7 @@ static bool_t hvm_complete_assist_req(ioreq_t *p)
>          break;
>      }
> 
> -    return 1;
> +    return 0; /* implicitly bins the i/o operation */

Actually that comment is not right. The operation is not binned; it's just 
already been done.

  Paul

>  }
> 
>  bool_t hvm_send_assist_req(ioreq_t *p)
> --
> 1.8.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel