Re: [PATCH v2 2/3] x86/ioreq server: Rename p2m_mmio_write_dm to p2m_ioreq_server

From: George Dunlap <george.dunlap@citrix.com>
To: "Yu, Zhang" <yu.c.zhang@linux.intel.com>,
	Paul Durrant <Paul.Durrant@citrix.com>,
	Jan Beulich <jbeulich@suse.com>, Wei Liu <wei.liu2@citrix.com>
Cc: Kevin Tian <kevin.tian@intel.com>,
	"Keir (Xen.org)" <keir@xen.org>,
	Andrew Cooper <Andrew.Cooper3@citrix.com>,
	"Tim (Xen.org)" <tim@xen.org>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
	"zhiyuan.lv@intel.com" <zhiyuan.lv@intel.com>,
	"jun.nakajima@intel.com" <jun.nakajima@intel.com>
Subject: Re: [PATCH v2 2/3] x86/ioreq server: Rename p2m_mmio_write_dm to p2m_ioreq_server
Date: Wed, 20 Apr 2016 16:02:25 +0100	[thread overview]
Message-ID: <57179A01.2060004@citrix.com> (raw)
In-Reply-To: <57161058.7060000@linux.intel.com>

On 19/04/16 12:02, Yu, Zhang wrote:
> 
> 
> On 4/19/2016 12:58 AM, Paul Durrant wrote:
>>> -----Original Message-----
>>> From: Xen-devel [mailto:xen-devel-bounces@lists.xen.org] On Behalf Of
>>> Jan
>>> Beulich
>>> Sent: 18 April 2016 17:47
>>> To: Paul Durrant
>>> Cc: Kevin Tian; Keir (Xen.org); Andrew Cooper; Tim (Xen.org); George
>>> Dunlap; xen-devel@lists.xen.org; yu.c.zhang@linux.intel.com;
>>> zhiyuan.lv@intel.com; jun.nakajima@intel.com
>>> Subject: Re: [Xen-devel] [PATCH v2 2/3] x86/ioreq server: Rename
>>> p2m_mmio_write_dm to p2m_ioreq_server
>>>
>>>>>> Paul Durrant <Paul.Durrant@citrix.com> 04/18/16 6:45 PM >>>
>>>> The original patch was posted before the cut-off IIRC so I'm not sure
>>>> of the policy regarding freeze-exceptions.
>>>
>>>    It was submitted before the feature freeze, yes, but didn't make
>>> it in by
>>> code freeze. So it's my understanding that an exception would be needed.
>>>
>>
>> Ok. Thanks for the clarification. IMO getting this in is worth the
>> freeze exception... it's a shame p2m_mmio_write_dm made it into 4.6.1.
>> It needs to go before it proliferates any further.
>>
> 
> Thanks, Paul.
> 
> So I suppose the only place we need change for this patch is
> for hvmmem_type_t, which should be defined like this?
> 
> typedef enum {
>     HVMMEM_ram_rw,             /* Normal read/write guest RAM */
>     HVMMEM_ram_ro,             /* Read-only; writes are discarded */
>     HVMMEM_mmio_dm,            /* Reads and write go to the device model */
> #if __XEN_INTERFACE_VERSION__ >= 0x00040700
>     HVMMEM_ioreq_server
> #else
>     HVMMEM_mmio_write_dm
> #endif
> } hvmmem_type_t;
> 
> Besides, does 4.7 still accept freeze exception? It would be great
> if we can get an approval for this.

Wait, do we *actually* need this?  Is anyone actually using this?

I'd say remove it, and if anyone complains, *then* do the #ifdef'ery as
a bug-fix.  I'm pretty sure that's Linux's policy -- You Must Keep
Userspace Working, but you can break it to see if anyone complains first.

 -George

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