diff mbox series

[RESEND] hw/cxl: fix the determination of illegal physical addresses

Message ID 20240819120317.12505-1-engguopeng@buaa.edu.cn
State New
Headers show
Series [RESEND] hw/cxl: fix the determination of illegal physical addresses | expand

Commit Message

peng guo Aug. 19, 2024, 12:03 p.m. UTC
When physical address range in the input payload of scan media command
exceeds static_mem_size but does not exceed the sum of static and dynamic
memory, the scan media mailbox command unexpectedly returns an error code
which is CXL_MBOX_INVALID_PA.

This patch determines whether the physical address is valid in two cases. 
If dynamic memory exists, check whether the address range of the request 
exceeds the range of static memory and dynamic memory.If dynamic memory 
does not exist, then check whether the address range of the request 
exceeds the static memory size.

Fixes: d61cc5b6a8d3 ("hw/cxl: Add get scan media capabilities cmd support")
Signed-off-by: peng guo <engguopeng@buaa.edu.cn>
---
 hw/cxl/cxl-mailbox-utils.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Jonathan Cameron Aug. 23, 2024, 3:14 p.m. UTC | #1
On Mon, 19 Aug 2024 20:03:17 +0800
peng guo <engguopeng@buaa.edu.cn> wrote:

> When physical address range in the input payload of scan media command
> exceeds static_mem_size but does not exceed the sum of static and dynamic
> memory, the scan media mailbox command unexpectedly returns an error code
> which is CXL_MBOX_INVALID_PA.
> 
> This patch determines whether the physical address is valid in two cases. 
> If dynamic memory exists, check whether the address range of the request 
> exceeds the range of static memory and dynamic memory.If dynamic memory 
> does not exist, then check whether the address range of the request 
> exceeds the static memory size.
> 
> Fixes: d61cc5b6a8d3 ("hw/cxl: Add get scan media capabilities cmd support")
Is that the right one, this code is affecting cmd_media_scan_media()
not the capabilities one which always limits to static_mem_size and
hence also looks wrong.

> Signed-off-by: peng guo <engguopeng@buaa.edu.cn>

As with the other patch, this needs to go to qemu-devel list
+ both should have gone to Davidlohr as author the patch you
are fixing (sort of it, it's mostly down to what order patches
landed in I think).

Fan, Davidlohr, do we want to just cover the DCD regions as
well with all the scan_media commands?


> ---
>  hw/cxl/cxl-mailbox-utils.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index 3ebbd32e10..b23c6b9b0b 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -1943,11 +1943,12 @@ static CXLRetCode cmd_media_scan_media(const struct cxl_cmd *cmd,
>      }
>      query_length = ldq_le_p(&in->length) * CXL_CACHE_LINE_SIZE;
>  
> -    if (query_start + query_length > cxl_dstate->static_mem_size) {
> -        return CXL_MBOX_INVALID_PA;
> -    }
> -    if (ct3d->dc.num_regions && query_start + query_length >=
> +    if (ct3d->dc.num_regions) {
> +        if (query_start + query_length >=
>              cxl_dstate->static_mem_size + ct3d->dc.total_capacity) {
> +                return CXL_MBOX_INVALID_PA;
> +            }
> +    } else if (query_start + query_length > cxl_dstate->static_mem_size) {
>          return CXL_MBOX_INVALID_PA;
>      }
Can we not rely on dc.total_capacity == 0 if num_regions == 0/

>
Davidlohr Bueso Sept. 4, 2024, 8:01 p.m. UTC | #2
On Fri, 23 Aug 2024, Jonathan Cameron wrote:\n
>On Mon, 19 Aug 2024 20:03:17 +0800
>peng guo <engguopeng@buaa.edu.cn> wrote:
>
>> When physical address range in the input payload of scan media command
>> exceeds static_mem_size but does not exceed the sum of static and dynamic
>> memory, the scan media mailbox command unexpectedly returns an error code
>> which is CXL_MBOX_INVALID_PA.
>>
>> This patch determines whether the physical address is valid in two cases.
>> If dynamic memory exists, check whether the address range of the request
>> exceeds the range of static memory and dynamic memory.If dynamic memory
							 ^ space for a new sentence
>> does not exist, then check whether the address range of the request
>> exceeds the static memory size.
>>
>> Fixes: d61cc5b6a8d3 ("hw/cxl: Add get scan media capabilities cmd support")
>Is that the right one, this code is affecting cmd_media_scan_media()
>not the capabilities one which always limits to static_mem_size and
>hence also looks wrong.

Yeah it is the right one - both commands were merged together (and
yes, they both need to be updated for dcd).

Maybe have a helper to consolidate all cases where such ranges are used?

uint64_t ct3d_get_total_size(CXLDeviceState *cxl_dstate, CXLType3Dev *ct3d)
{

	return cxl_dstate->static_mem_size + ct3d->dc.total_capacity;
}

>
>> Signed-off-by: peng guo <engguopeng@buaa.edu.cn>
>
>As with the other patch, this needs to go to qemu-devel list
>+ both should have gone to Davidlohr as author the patch you
>are fixing (sort of it, it's mostly down to what order patches
>landed in I think).
>
>Fan, Davidlohr, do we want to just cover the DCD regions as
>well with all the scan_media commands?

Yeah, I think so - particularly since poison management already
considers dcd for CXL_MBOX_INVALID_PA.

Thanks,
Davidlohr

>
>
>> ---
>>  hw/cxl/cxl-mailbox-utils.c | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
>> index 3ebbd32e10..b23c6b9b0b 100644
>> --- a/hw/cxl/cxl-mailbox-utils.c
>> +++ b/hw/cxl/cxl-mailbox-utils.c
>> @@ -1943,11 +1943,12 @@ static CXLRetCode cmd_media_scan_media(const struct cxl_cmd *cmd,
>>      }
>>      query_length = ldq_le_p(&in->length) * CXL_CACHE_LINE_SIZE;
>>
>> -    if (query_start + query_length > cxl_dstate->static_mem_size) {
>> -        return CXL_MBOX_INVALID_PA;
>> -    }
>> -    if (ct3d->dc.num_regions && query_start + query_length >=
>> +    if (ct3d->dc.num_regions) {
>> +        if (query_start + query_length >=
>>              cxl_dstate->static_mem_size + ct3d->dc.total_capacity) {
>> +                return CXL_MBOX_INVALID_PA;
>> +            }
>> +    } else if (query_start + query_length > cxl_dstate->static_mem_size) {
>>          return CXL_MBOX_INVALID_PA;
>>      }
>Can we not rely on dc.total_capacity == 0 if num_regions == 0/
>
>>
>
diff mbox series

Patch

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 3ebbd32e10..b23c6b9b0b 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -1943,11 +1943,12 @@  static CXLRetCode cmd_media_scan_media(const struct cxl_cmd *cmd,
     }
     query_length = ldq_le_p(&in->length) * CXL_CACHE_LINE_SIZE;
 
-    if (query_start + query_length > cxl_dstate->static_mem_size) {
-        return CXL_MBOX_INVALID_PA;
-    }
-    if (ct3d->dc.num_regions && query_start + query_length >=
+    if (ct3d->dc.num_regions) {
+        if (query_start + query_length >=
             cxl_dstate->static_mem_size + ct3d->dc.total_capacity) {
+                return CXL_MBOX_INVALID_PA;
+            }
+    } else if (query_start + query_length > cxl_dstate->static_mem_size) {
         return CXL_MBOX_INVALID_PA;
     }