cxl/core: Fix the UUID of CXL vendor debug Log identifier

[PATCH v2] cxl/core: Fix the UUID of CXL vendor debug Log identifier

Posted by peng guo 1 year, 7 months ago

Fix the definition value of DEFINE_CXL_VENDOR_DEBUG_UUID to match the
CXL r3.1 specification, although this value is not currently used.

All CXL devices that support a debug log shall support the Vendor Debug
Log to allow the log to be accessed through a common host driver, for any
device, all versions of the CXL specification define the same value with
Log Identifier of: 5e1819d9-11a9-400c-811f-d60719403d86

refer to:
CXL spec r2.0 Table 169
CXL spec r3.0 Table 8-62
CXL spec r3.1 Table 8-71

Fixes: 49be6dd80751 ("cxl/mbox: Move command definitions to common location")
Signed-off-by: peng guo <engguopeng@buaa.edu.cn>
---
 v1 -> v2: update commit message  and addressed review comments

 drivers/cxl/cxlmem.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index af8169ccdbc0..feb1106559d2 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -563,7 +563,7 @@ enum cxl_opcode {
 		  0x3b, 0x3f, 0x17)
 
 #define DEFINE_CXL_VENDOR_DEBUG_UUID                                           \
-	UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
+	UUID_INIT(0x5e1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
 		  0x40, 0x3d, 0x86)
 
 struct cxl_mbox_get_supported_logs {
-- 
2.43.0

Re: [PATCH v2] cxl/core: Fix the UUID of CXL vendor debug Log identifier

Posted by Alison Schofield 1 year, 7 months ago

On Tue, Jul 09, 2024 at 10:12:39PM +0800, peng guo wrote:
> Fix the definition value of DEFINE_CXL_VENDOR_DEBUG_UUID to match the
> CXL r3.1 specification, although this value is not currently used.

I thought the value was actually used.
Please help me understand by responding to v1 review:
https://lore.kernel.org/Zow0Aw+vrXShXv+n@aschofie-mobl2/

--Alison


> 
> All CXL devices that support a debug log shall support the Vendor Debug
> Log to allow the log to be accessed through a common host driver, for any
> device, all versions of the CXL specification define the same value with
> Log Identifier of: 5e1819d9-11a9-400c-811f-d60719403d86
> 
> refer to:
> CXL spec r2.0 Table 169
> CXL spec r3.0 Table 8-62
> CXL spec r3.1 Table 8-71
> 
> Fixes: 49be6dd80751 ("cxl/mbox: Move command definitions to common location")
> Signed-off-by: peng guo <engguopeng@buaa.edu.cn>
> ---
>  v1 -> v2: update commit message  and addressed review comments
> 
>  drivers/cxl/cxlmem.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index af8169ccdbc0..feb1106559d2 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -563,7 +563,7 @@ enum cxl_opcode {
>  		  0x3b, 0x3f, 0x17)
>  
>  #define DEFINE_CXL_VENDOR_DEBUG_UUID                                           \
> -	UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
> +	UUID_INIT(0x5e1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
>  		  0x40, 0x3d, 0x86)
>  
>  struct cxl_mbox_get_supported_logs {
> -- 
> 2.43.0
>

Re: [PATCH v2] cxl/core: Fix the UUID of CXL vendor debug Log identifier

Posted by Dan Williams 1 year, 7 months ago

Alison Schofield wrote:
> On Tue, Jul 09, 2024 at 10:12:39PM +0800, peng guo wrote:
> > Fix the definition value of DEFINE_CXL_VENDOR_DEBUG_UUID to match the
> > CXL r3.1 specification, although this value is not currently used.
> 
> I thought the value was actually used.
> Please help me understand by responding to v1 review:
> https://lore.kernel.org/Zow0Aw+vrXShXv+n@aschofie-mobl2/

I assume that this was some "by inspection" reason for the "how found".
This effectively proves that no one has ever tried to use
CXL_MEM_COMMAND_ID_CLEAR_LOG with the vendor debug log. It could be the
case that everyone to date that ever had that need is just using RAW
commands to do it.

To me this is another example of Linux command wrapping CXL command
failure.

To your point though, it would be good to get that user visible effect
into the changelog so that distros can decide about the impact of
backporting this fix.

Re: [PATCH v2] cxl/core: Fix the UUID of CXL vendor debug Log identifier

Posted by Dave Jiang 1 year, 7 months ago


On 7/9/24 7:12 AM, peng guo wrote:
> Fix the definition value of DEFINE_CXL_VENDOR_DEBUG_UUID to match the
> CXL r3.1 specification, although this value is not currently used.
> 
> All CXL devices that support a debug log shall support the Vendor Debug
> Log to allow the log to be accessed through a common host driver, for any
> device, all versions of the CXL specification define the same value with
> Log Identifier of: 5e1819d9-11a9-400c-811f-d60719403d86
> 
> refer to:
> CXL spec r2.0 Table 169
> CXL spec r3.0 Table 8-62
> CXL spec r3.1 Table 8-71
> 
> Fixes: 49be6dd80751 ("cxl/mbox: Move command definitions to common location")

Thanks for the update Peng. 

This one is tricky as the definition has been moved twice, but the original commit that introduced the error was here:
472b1ce6e9d6 ("cxl/mem: Enable commands via CEL")

I will update that when I apply the patch.

Next time for follow on patch revisions, please post as independent email rather than threaded behind the previous submission. Thanks! 

> Signed-off-by: peng guo <engguopeng@buaa.edu.cn>
> ---
>  v1 -> v2: update commit message  and addressed review comments
> 
>  drivers/cxl/cxlmem.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index af8169ccdbc0..feb1106559d2 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -563,7 +563,7 @@ enum cxl_opcode {
>  		  0x3b, 0x3f, 0x17)
>  
>  #define DEFINE_CXL_VENDOR_DEBUG_UUID                                           \
> -	UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
> +	UUID_INIT(0x5e1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 0x07, 0x19,     \
>  		  0x40, 0x3d, 0x86)
>  
>  struct cxl_mbox_get_supported_logs {