diff mbox series

[1/3] RDMA/rxe: Use sizeof instead of hard code number

Message ID 20240822065223.1117056-2-pizhenwei@bytedance.com (mailing list archive)
State Accepted
Delegated to: Jason Gunthorpe
Headers show
Series RDMA/rxe misc fixes | expand

Commit Message

zhenwei pi Aug. 22, 2024, 6:52 a.m. UTC
Use 'sizeof(union rdma_network_hdr)' instead of hard code GRH length
for GSI and UD.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 drivers/infiniband/sw/rxe/rxe_resp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Zhu Yanjun Aug. 22, 2024, 11:59 a.m. UTC | #1
在 2024/8/22 14:52, zhenwei pi 写道:
> Use 'sizeof(union rdma_network_hdr)' instead of hard code GRH length
> for GSI and UD.
> 
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   drivers/infiniband/sw/rxe/rxe_resp.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> index 6596a85723c9..bf8f4bc8c5c8 100644
> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> @@ -351,7 +351,7 @@ static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
>   
>   		for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
>   			recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
> -		if (payload + 40 > recv_buffer_len) {
> +		if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {

The definition of union rdma_network_hdr is as below

  797 union rdma_network_hdr {
  798         struct ib_grh ibgrh;
  799         struct {
  800                 /* The IB spec states that if it's IPv4, the header
  801                  * is located in the last 20 bytes of the header.
  802                  */
  803                 u8              reserved[20];
  804                 struct iphdr    roce4grh;
  805         };
  806 };

The length is 40 byte.

But in this,

sizeof(struct iphdr) (20) + sizeof(struct udphdr) (8) + sizeof(struct 
rxe_bth) (12) = 40

Not sure if we should use sizeof(union rdma_network_hdr) or 
(sizeof(struct iphdr) + sizeof(struct udphdr) + sizeof(struct rxe_bth)) 
in this place.

Best Regards,
Zhu Yanjun


>   			rxe_dbg_qp(qp, "The receive buffer is too small for this UD packet.\n");
>   			return RESPST_ERR_LENGTH;
>   		}
Jason Gunthorpe Aug. 22, 2024, 12:36 p.m. UTC | #2
On Thu, Aug 22, 2024 at 07:59:32PM +0800, Zhu Yanjun wrote:
> 在 2024/8/22 14:52, zhenwei pi 写道:
> > Use 'sizeof(union rdma_network_hdr)' instead of hard code GRH length
> > for GSI and UD.
> > 
> > Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> > ---
> >   drivers/infiniband/sw/rxe/rxe_resp.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> > index 6596a85723c9..bf8f4bc8c5c8 100644
> > --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> > +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> > @@ -351,7 +351,7 @@ static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
> >   		for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
> >   			recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
> > -		if (payload + 40 > recv_buffer_len) {
> > +		if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {
> 
> The definition of union rdma_network_hdr is as below
> 
>  797 union rdma_network_hdr {
>  798         struct ib_grh ibgrh;
>  799         struct {
>  800                 /* The IB spec states that if it's IPv4, the header
>  801                  * is located in the last 20 bytes of the header.
>  802                  */
>  803                 u8              reserved[20];
>  804                 struct iphdr    roce4grh;
>  805         };
>  806 };
> 
> The length is 40 byte.

This looks like the right struct to me if this is talking about the
special 40 byte blob that is placed in front of UD verbs completions.

Jason
Zhu Yanjun Aug. 23, 2024, 5:56 a.m. UTC | #3
在 2024/8/23 10:30, zhenwei pi 写道:
>
> On 8/22/24 20:36, Jason Gunthorpe wrote:
> > On Thu, Aug 22, 2024 at 07:59:32PM +0800, Zhu Yanjun wrote:
> >> 在 2024/8/22 14:52, zhenwei pi 写道:
> >>> Use 'sizeof(union rdma_network_hdr)' instead of hard code GRH length
> >>> for GSI and UD.
> >>>
> >>> Signed-off-by: zhenwei pi
> >>> ---
> >>> drivers/infiniband/sw/rxe/rxe_resp.c | 2 +-
> >>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c 
> b/drivers/infiniband/sw/rxe/rxe_resp.c
> >>> index 6596a85723c9..bf8f4bc8c5c8 100644
> >>> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> >>> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> >>> @@ -351,7 +351,7 @@ static enum resp_states 
> rxe_resp_check_length(struct rxe_qp *qp,
> >>> for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
> >>> recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
> >>> - if (payload + 40 > recv_buffer_len) {
> >>> + if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {
> >>
> >> The definition of union rdma_network_hdr is as below
> >>
> >> 797 union rdma_network_hdr {
> >> 798 struct ib_grh ibgrh;
> >> 799 struct {
> >> 800 /* The IB spec states that if it's IPv4, the header
> >> 801 * is located in the last 20 bytes of the header.
> >> 802 */
> >> 803 u8 reserved[20];
> >> 804 struct iphdr roce4grh;
> >> 805 };
> >> 806 };
> >>
> >> The length is 40 byte.
> >
> > This looks like the right struct to me if this is talking about the
> > special 40 byte blob that is placed in front of UD verbs completions.
> >
> > Jason
>
> Yes, this is the front part(40 bytes) of UD/GSI verbs completion.
>
When running, you can print the value of the front part (40 bytes) of 
UD/GSI to confirm that these 40 bytes are the union rdma_network_hdr.

If these 40 bytes are the union rdma_network_hdr,

Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Best Regards,

Zhu Yanjun

>
> -- 
> zhenwei pi
>
zhenwei pi Aug. 23, 2024, 8:23 a.m. UTC | #4
On 8/23/24 13:56, Zhu Yanjun wrote:
> 
> 在 2024/8/23 10:30, zhenwei pi 写道:
>>
>> On 8/22/24 20:36, Jason Gunthorpe wrote:
>> > On Thu, Aug 22, 2024 at 07:59:32PM +0800, Zhu Yanjun wrote:
>> >> 在 2024/8/22 14:52, zhenwei pi 写道:
>> >>> Use 'sizeof(union rdma_network_hdr)' instead of hard code GRH length
>> >>> for GSI and UD.
>> >>>
>> >>> Signed-off-by: zhenwei pi
>> >>> ---
>> >>> drivers/infiniband/sw/rxe/rxe_resp.c | 2 +-
>> >>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> >>>
>> >>> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/ 
>> infiniband/sw/rxe/rxe_resp.c
>> >>> index 6596a85723c9..bf8f4bc8c5c8 100644
>> >>> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
>> >>> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
>> >>> @@ -351,7 +351,7 @@ static enum resp_states 
>> rxe_resp_check_length(struct rxe_qp *qp,
>> >>> for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
>> >>> recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
>> >>> - if (payload + 40 > recv_buffer_len) {
>> >>> + if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {
>> >>
>> >> The definition of union rdma_network_hdr is as below
>> >>
>> >> 797 union rdma_network_hdr {
>> >> 798 struct ib_grh ibgrh;
>> >> 799 struct {
>> >> 800 /* The IB spec states that if it's IPv4, the header
>> >> 801 * is located in the last 20 bytes of the header.
>> >> 802 */
>> >> 803 u8 reserved[20];
>> >> 804 struct iphdr roce4grh;
>> >> 805 };
>> >> 806 };
>> >>
>> >> The length is 40 byte.
>> >
>> > This looks like the right struct to me if this is talking about the
>> > special 40 byte blob that is placed in front of UD verbs completions.
>> >
>> > Jason
>>
>> Yes, this is the front part(40 bytes) of UD/GSI verbs completion.
>>
> When running, you can print the value of the front part (40 bytes) of 
> UD/GSI to confirm that these 40 bytes are the union rdma_network_hdr.
> 
> If these 40 bytes are the union rdma_network_hdr,
> 
> Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> 
> Best Regards,
> 
> Zhu Yanjun
> 

Hi Yanjun,

I test on mlx-cx5 by command: ibv_ud_pingpong -d mlx5_2 -g 3 -r 1 -n 1

Dump the front 64 bytes:
00000000000000000000000000000000000000004502043436f340000111448c
0a0b73120a0b73107b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b

Byte[0, 20) (rdma_network_hdr::reserved[20]) are filled by zero, 
byte[20,40) (rdma_network_hdr::roce4grh) are filled by IPv4 header.

>>
>> -- 
>> zhenwei pi
>>
Zhu Yanjun Aug. 23, 2024, 9:17 a.m. UTC | #5
在 2024/8/23 16:23, zhenwei pi 写道:
>
>
> On 8/23/24 13:56, Zhu Yanjun wrote:
>>
>> 在 2024/8/23 10:30, zhenwei pi 写道:
>>>
>>> On 8/22/24 20:36, Jason Gunthorpe wrote:
>>> > On Thu, Aug 22, 2024 at 07:59:32PM +0800, Zhu Yanjun wrote:
>>> >> 在 2024/8/22 14:52, zhenwei pi 写道:
>>> >>> Use 'sizeof(union rdma_network_hdr)' instead of hard code GRH 
>>> length
>>> >>> for GSI and UD.
>>> >>>
>>> >>> Signed-off-by: zhenwei pi
>>> >>> ---
>>> >>> drivers/infiniband/sw/rxe/rxe_resp.c | 2 +-
>>> >>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>> >>>
>>> >>> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/ 
>>> infiniband/sw/rxe/rxe_resp.c
>>> >>> index 6596a85723c9..bf8f4bc8c5c8 100644
>>> >>> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
>>> >>> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
>>> >>> @@ -351,7 +351,7 @@ static enum resp_states 
>>> rxe_resp_check_length(struct rxe_qp *qp,
>>> >>> for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
>>> >>> recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
>>> >>> - if (payload + 40 > recv_buffer_len) {
>>> >>> + if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {
>>> >>
>>> >> The definition of union rdma_network_hdr is as below
>>> >>
>>> >> 797 union rdma_network_hdr {
>>> >> 798 struct ib_grh ibgrh;
>>> >> 799 struct {
>>> >> 800 /* The IB spec states that if it's IPv4, the header
>>> >> 801 * is located in the last 20 bytes of the header.
>>> >> 802 */
>>> >> 803 u8 reserved[20];
>>> >> 804 struct iphdr roce4grh;
>>> >> 805 };
>>> >> 806 };
>>> >>
>>> >> The length is 40 byte.
>>> >
>>> > This looks like the right struct to me if this is talking about the
>>> > special 40 byte blob that is placed in front of UD verbs completions.
>>> >
>>> > Jason
>>>
>>> Yes, this is the front part(40 bytes) of UD/GSI verbs completion.
>>>
>> When running, you can print the value of the front part (40 bytes) of 
>> UD/GSI to confirm that these 40 bytes are the union rdma_network_hdr.
>>
>> If these 40 bytes are the union rdma_network_hdr,
>>
>> Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
>>
>> Best Regards,
>>
>> Zhu Yanjun
>>
>
> Hi Yanjun,
>
> I test on mlx-cx5 by command: ibv_ud_pingpong -d mlx5_2 -g 3 -r 1 -n 1
>
> Dump the front 64 bytes:
> 00000000000000000000000000000000000000004502043436f340000111448c
> 0a0b73120a0b73107b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b
>
> Byte[0, 20) (rdma_network_hdr::reserved[20]) are filled by zero, 
> byte[20,40) (rdma_network_hdr::roce4grh) are filled by IPv4 header.

Got it. Thanks a lot.

I am fine with your commit.

Best Regards,

Zhu Yanjun

>
>>>
>>> -- 
>>> zhenwei pi
>>>
>
diff mbox series

Patch

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index 6596a85723c9..bf8f4bc8c5c8 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -351,7 +351,7 @@  static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
 
 		for (i = 0; i < qp->resp.wqe->dma.num_sge; i++)
 			recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
-		if (payload + 40 > recv_buffer_len) {
+		if (payload + sizeof(union rdma_network_hdr) > recv_buffer_len) {
 			rxe_dbg_qp(qp, "The receive buffer is too small for this UD packet.\n");
 			return RESPST_ERR_LENGTH;
 		}