Re: [Xen-devel] [PATCH v2 08/16] xen/hvm/params: Add a new delivery type for event-channel in HVM_PARAM_CALLBACK_IRQ

[Andrew Cooper]

On 18/01/16 12:46, Stefano Stabellini wrote:
> On Mon, 18 Jan 2016, Andrew Cooper wrote:
>> On 18/01/16 12:38, Stefano Stabellini wrote:
>>> On Fri, 15 Jan 2016, Shannon Zhao wrote:
>>>> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>>>>
>>>> Add a new delivery type:
>>>> val[63:56] == 3: val[15:8] is flag: val[7:0] is a PPI.
>>>> To the flag, bit 0 stands the interrupt mode is edge(1) or level(0) and
>>>> bit 1 stands the interrupt polarity is active low(1) or high(0).
>>>>
>>>> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>>>> ---
>>>>  include/xen/interface/hvm/params.h | 5 +++++
>>>>  1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/include/xen/interface/hvm/params.h b/include/xen/interface/hvm/params.h
>>>> index a6c7991..550688a 100644
>>>> --- a/include/xen/interface/hvm/params.h
>>>> +++ b/include/xen/interface/hvm/params.h
>>>> @@ -34,6 +34,11 @@
>>>>   *                  Domain = val[47:32], Bus  = val[31:16],
>>>>   *                  DevFn  = val[15: 8], IntX = val[ 1: 0]
>>>>   * val[63:56] == 2: val[7:0] is a vector number.
>>>> + * val[63:56] == 3: val[15:8] is flag of event-channel interrupt:
>>>> + *                      bit 0: interrupt is edge(1) or level(0) triggered
>>>> + *                      bit 1: interrupt is active low(1) or high(0)
>>>> + *                  val[7:0] is PPI number used by event-channel.
>>>> + *                  This is only used by ARM/ARM64.
>>>>   * If val == 0 then CPU0 event-channel notifications are not delivered.
>>>>   */
>>>>  #define HVM_PARAM_CALLBACK_IRQ 0
>>> Andrew, I think that this patch is correct. Looking back at your
>>> previous comment (http://marc.info/?l=devicetree&m=144804014214262&w=2),
>>> is it possible that you were confused by enum callback_via_type, which
>>> is internal to Xen and offset'ed by 1 compared to the described values
>>> in xen/include/public/hvm/params.h?
>>>
>>> If not, and indeed somebody introduced one more field but failed to
>>> document it, then I suggest she sends a patch to fix the issue as soon
>>> as possible.
>> I was indeed confused - the ABI is utterly mad.
> All right. In that case, Shannon, you can add my
>
> Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
>
>
>> However, this change does need rebasing over c/s ca5c54b, which was the
>> result of the original discussion.
> c/s ca5c54b is for Xen, while this is a Linux patch (Linux has its own
> set of Xen headers).

All ABI changes need to happen in the Xen public headers first.  This
patch cannot be accepted yet.

~Andrew