Re: [PATCH v3 1/2] cxl/core: correct length of DPA field masks

[Shiyang Ruan <ruansy.fnst@fujitsu.com>]

在 2024/5/1 5:00, Alison Schofield 写道:
> On Wed, Apr 17, 2024 at 03:50:52PM +0800, Shiyang Ruan wrote:
>> The length of Physical Address in General Media Event Record/DRAM Event
>> Record is 64-bit, so the field mask should be defined as such length.
>> Otherwise, this causes cxl_general_media and cxl_dram tracepoints to
>> mask off the upper-32-bits of DPA addresses. The cxl_poison event is
>> unaffected.
>>
>> If userspace was doing its own DPA-to-HPA translation this could lead to
>> incorrect page retirement decisions, but there is no known consumer
>> (like rasdaemon) of this event today.
>>
>> Fixes: d54a531a430b ("cxl/mem: Trace General Media Event Record")
>> Cc: <stable@vger.kernel.org>
>> Cc: Dan Williams <dan.j.williams@intel.com>
>> Cc: Davidlohr Bueso <dave@stgolabs.net>
>> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Cc: Ira Weiny <ira.weiny@intel.com>
>> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> 
> Hi Ruan,
> 
> This fixup is important for the Event DPA->HPA translation work, so I
> grabbed it, updated it with most* of the review comments, and posted
> with that set. I expect you saw that in your mailbox.

Yes, I saw that.  Nice fix!

> 
> DaveJ queued it in a topic branch for 6.10 here:
> https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/log/?h=for-6.10/dpa-to-hpa
> 

That's good!

> *I did not create a common mask for events and poison because I wanted to
> limit the changes. If you'd like to make that change it would be welcomed.

Ok~


--
Thanks,
Ruan.

> 
> -- Alison
> 
>> ---
>>   drivers/cxl/core/trace.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
>> index e5f13260fc52..cdfce932d5b1 100644
>> --- a/drivers/cxl/core/trace.h
>> +++ b/drivers/cxl/core/trace.h
>> @@ -253,7 +253,7 @@ TRACE_EVENT(cxl_generic_event,
>>    * DRAM Event Record
>>    * CXL rev 3.0 section 8.2.9.2.1.2; Table 8-44
>>    */
>> -#define CXL_DPA_FLAGS_MASK			0x3F
>> +#define CXL_DPA_FLAGS_MASK			0x3FULL
>>   #define CXL_DPA_MASK				(~CXL_DPA_FLAGS_MASK)
>>   
>>   #define CXL_DPA_VOLATILE			BIT(0)
>> -- 
>> 2.34.1
>>