[PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Yonatan Nachum]

From: Michael Margolin <mrgolin@amazon.com>

Change the SQ depth validation to take into account the SQ WQE size.
This is needed since when using 128-byte WQE the max SQ depth is cut in
half. On create QP command, userspace provides SQ ring size which is SQ
depth X WQE size so we can calculate the requested WQE size in the
kernel.

Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
Reviewed-by: Michael Margolin <mrgolin@amazon.com>
Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
---
 drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index 7bd0838ebc99..eb95ed4e25f7 100644
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -612,14 +612,27 @@ static int qp_mmap_entries_setup(struct efa_qp *qp,
 	return -ENOMEM;
 }
 
+static int efa_calc_sq_wqe_size(u32 sq_ring_size, u32 max_send_wr)
+{
+	return max_send_wr == 0 ? 0 : sq_ring_size / max_send_wr;
+}
+
+static u32 efa_calc_sq_max_depth(struct efa_dev *dev, u32 sq_wqe_size)
+{
+	return sq_wqe_size == 0 ? 0 :
+		rounddown_pow_of_two(dev->dev_attr.max_llq_size / sq_wqe_size);
+}
+
 static int efa_qp_validate_cap(struct efa_dev *dev,
-			       struct ib_qp_init_attr *init_attr)
+			       struct ib_qp_init_attr *init_attr,
+			       u32 sq_wqe_size)
 {
-	if (init_attr->cap.max_send_wr > dev->dev_attr.max_sq_depth) {
+	u32 sq_max_depth = efa_calc_sq_max_depth(dev, sq_wqe_size);
+
+	if (init_attr->cap.max_send_wr > sq_max_depth) {
 		ibdev_dbg(&dev->ibdev,
 			  "qp: requested send wr[%u] exceeds the max[%u]\n",
-			  init_attr->cap.max_send_wr,
-			  dev->dev_attr.max_sq_depth);
+			  init_attr->cap.max_send_wr, sq_max_depth);
 		return -EINVAL;
 	}
 	if (init_attr->cap.max_recv_wr > dev->dev_attr.max_rq_depth) {
@@ -686,19 +699,12 @@ int efa_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init_attr,
 	struct efa_qp *qp = to_eqp(ibqp);
 	struct efa_ucontext *ucontext;
 	u16 supported_efa_flags = 0;
+	u32 sq_wqe_size;
 	int err;
 
 	ucontext = rdma_udata_to_drv_context(udata, struct efa_ucontext,
 					     ibucontext);
 
-	err = efa_qp_validate_cap(dev, init_attr);
-	if (err)
-		goto err_out;
-
-	err = efa_qp_validate_attr(dev, init_attr);
-	if (err)
-		goto err_out;
-
 	err = ib_copy_validate_udata_in_cm(udata, cmd, driver_qp_type, 0);
 	if (err)
 		goto err_out;
@@ -720,6 +726,15 @@ int efa_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init_attr,
 		goto err_out;
 	}
 
+	sq_wqe_size = efa_calc_sq_wqe_size(cmd.sq_ring_size, init_attr->cap.max_send_wr);
+	err = efa_qp_validate_cap(dev, init_attr, sq_wqe_size);
+	if (err)
+		goto err_out;
+
+	err = efa_qp_validate_attr(dev, init_attr);
+	if (err)
+		goto err_out;
+
 	create_qp_params.uarn = ucontext->uarn;
 	create_qp_params.pd = to_epd(ibqp->pd)->pdn;
 
-- 
2.50.1

Re: [PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Leon Romanovsky]

On Thu, May 07, 2026 at 11:21:10AM +0000, Yonatan Nachum wrote:
> From: Michael Margolin <mrgolin@amazon.com>
> 
> Change the SQ depth validation to take into account the SQ WQE size.
> This is needed since when using 128-byte WQE the max SQ depth is cut in
> half. On create QP command, userspace provides SQ ring size which is SQ
> depth X WQE size so we can calculate the requested WQE size in the
> kernel.
> 
> Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
> Reviewed-by: Michael Margolin <mrgolin@amazon.com>
> Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
> ---
>  drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
>  1 file changed, 27 insertions(+), 12 deletions(-)

Please add Fixes line.

Thanks

> 
> diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
> index 7bd0838ebc99..eb95ed4e25f7 100644
> --- a/drivers/infiniband/hw/efa/efa_verbs.c
> +++ b/drivers/infiniband/hw/efa/efa_verbs.c
> @@ -612,14 +612,27 @@ static int qp_mmap_entries_setup(struct efa_qp *qp,
>  	return -ENOMEM;
>  }
>  
> +static int efa_calc_sq_wqe_size(u32 sq_ring_size, u32 max_send_wr)
> +{
> +	return max_send_wr == 0 ? 0 : sq_ring_size / max_send_wr;
> +}
> +
> +static u32 efa_calc_sq_max_depth(struct efa_dev *dev, u32 sq_wqe_size)
> +{
> +	return sq_wqe_size == 0 ? 0 :
> +		rounddown_pow_of_two(dev->dev_attr.max_llq_size / sq_wqe_size);
> +}
> +
>  static int efa_qp_validate_cap(struct efa_dev *dev,
> -			       struct ib_qp_init_attr *init_attr)
> +			       struct ib_qp_init_attr *init_attr,
> +			       u32 sq_wqe_size)
>  {
> -	if (init_attr->cap.max_send_wr > dev->dev_attr.max_sq_depth) {
> +	u32 sq_max_depth = efa_calc_sq_max_depth(dev, sq_wqe_size);
> +
> +	if (init_attr->cap.max_send_wr > sq_max_depth) {
>  		ibdev_dbg(&dev->ibdev,
>  			  "qp: requested send wr[%u] exceeds the max[%u]\n",
> -			  init_attr->cap.max_send_wr,
> -			  dev->dev_attr.max_sq_depth);
> +			  init_attr->cap.max_send_wr, sq_max_depth);
>  		return -EINVAL;
>  	}
>  	if (init_attr->cap.max_recv_wr > dev->dev_attr.max_rq_depth) {
> @@ -686,19 +699,12 @@ int efa_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init_attr,
>  	struct efa_qp *qp = to_eqp(ibqp);
>  	struct efa_ucontext *ucontext;
>  	u16 supported_efa_flags = 0;
> +	u32 sq_wqe_size;
>  	int err;
>  
>  	ucontext = rdma_udata_to_drv_context(udata, struct efa_ucontext,
>  					     ibucontext);
>  
> -	err = efa_qp_validate_cap(dev, init_attr);
> -	if (err)
> -		goto err_out;
> -
> -	err = efa_qp_validate_attr(dev, init_attr);
> -	if (err)
> -		goto err_out;
> -
>  	err = ib_copy_validate_udata_in_cm(udata, cmd, driver_qp_type, 0);
>  	if (err)
>  		goto err_out;
> @@ -720,6 +726,15 @@ int efa_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init_attr,
>  		goto err_out;
>  	}
>  
> +	sq_wqe_size = efa_calc_sq_wqe_size(cmd.sq_ring_size, init_attr->cap.max_send_wr);
> +	err = efa_qp_validate_cap(dev, init_attr, sq_wqe_size);
> +	if (err)
> +		goto err_out;
> +
> +	err = efa_qp_validate_attr(dev, init_attr);
> +	if (err)
> +		goto err_out;
> +
>  	create_qp_params.uarn = ucontext->uarn;
>  	create_qp_params.pd = to_epd(ibqp->pd)->pdn;
>  
> -- 
> 2.50.1
> 
> 

Re: [PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Yonatan Nachum]

On Wed, May 13, 2026 at 08:38:12PM +0300, Leon Romanovsky wrote:
> On Thu, May 07, 2026 at 11:21:10AM +0000, Yonatan Nachum wrote:
> > From: Michael Margolin <mrgolin@amazon.com>
> > 
> > Change the SQ depth validation to take into account the SQ WQE size.
> > This is needed since when using 128-byte WQE the max SQ depth is cut in
> > half. On create QP command, userspace provides SQ ring size which is SQ
> > depth X WQE size so we can calculate the requested WQE size in the
> > kernel.
> > 
> > Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
> > Reviewed-by: Michael Margolin <mrgolin@amazon.com>
> > Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
> > ---
> >  drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
> >  1 file changed, 27 insertions(+), 12 deletions(-)
> 
> Please add Fixes line.
> 
> Thanks

There is no Fixes tag as this is not a bug fix. The existing validation
works but is overly permissive — it doesn't account for WQE size when
checking max SQ depth. Without it, the device would reject the request
downstream. This patch tightens the validation to fail early in the
kernel.

Re: [PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Leon Romanovsky]

On Wed, May 13, 2026 at 07:24:51PM +0000, Yonatan Nachum wrote:
> On Wed, May 13, 2026 at 08:38:12PM +0300, Leon Romanovsky wrote:
> > On Thu, May 07, 2026 at 11:21:10AM +0000, Yonatan Nachum wrote:
> > > From: Michael Margolin <mrgolin@amazon.com>
> > > 
> > > Change the SQ depth validation to take into account the SQ WQE size.
> > > This is needed since when using 128-byte WQE the max SQ depth is cut in
> > > half. On create QP command, userspace provides SQ ring size which is SQ
> > > depth X WQE size so we can calculate the requested WQE size in the
> > > kernel.
> > > 
> > > Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
> > > Reviewed-by: Michael Margolin <mrgolin@amazon.com>
> > > Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
> > > ---
> > >  drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
> > >  1 file changed, 27 insertions(+), 12 deletions(-)
> > 
> > Please add Fixes line.
> > 
> > Thanks
> 
> There is no Fixes tag as this is not a bug fix. The existing validation
> works but is overly permissive — it doesn't account for WQE size when
> checking max SQ depth. Without it, the device would reject the request
> downstream. This patch tightens the validation to fail early in the
> kernel.

So why do we need kernel patch after all?

Thanks

Re: [PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Yonatan Nachum]

On Thu, May 14, 2026 at 07:28:12PM +0300, Leon Romanovsky wrote:
> On Wed, May 13, 2026 at 07:24:51PM +0000, Yonatan Nachum wrote:
> > On Wed, May 13, 2026 at 08:38:12PM +0300, Leon Romanovsky wrote:
> > > On Thu, May 07, 2026 at 11:21:10AM +0000, Yonatan Nachum wrote:
> > > > From: Michael Margolin <mrgolin@amazon.com>
> > > > 
> > > > Change the SQ depth validation to take into account the SQ WQE size.
> > > > This is needed since when using 128-byte WQE the max SQ depth is cut in
> > > > half. On create QP command, userspace provides SQ ring size which is SQ
> > > > depth X WQE size so we can calculate the requested WQE size in the
> > > > kernel.
> > > > 
> > > > Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
> > > > Reviewed-by: Michael Margolin <mrgolin@amazon.com>
> > > > Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
> > > > ---
> > > >  drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
> > > >  1 file changed, 27 insertions(+), 12 deletions(-)
> > > 
> > > Please add Fixes line.
> > > 
> > > Thanks
> > 
> > There is no Fixes tag as this is not a bug fix. The existing validation
> > works but is overly permissive — it doesn't account for WQE size when
> > checking max SQ depth. Without it, the device would reject the request
> > downstream. This patch tightens the validation to fail early in the
> > kernel.
> 
> So why do we need kernel patch after all?
> 
> Thanks

The driver already validates max_send_wr against max_sq_depth — this
patch just makes that check accurate for the 128-byte WQE case. This
also gives better error reporting as opposed to device failure.

Re: [PATCH for-next] RDMA/efa: Validate SQ depth based on WQE size

[Leon Romanovsky]

On Thu, May 14, 2026 at 08:45:21PM +0000, Yonatan Nachum wrote:
> On Thu, May 14, 2026 at 07:28:12PM +0300, Leon Romanovsky wrote:
> > On Wed, May 13, 2026 at 07:24:51PM +0000, Yonatan Nachum wrote:
> > > On Wed, May 13, 2026 at 08:38:12PM +0300, Leon Romanovsky wrote:
> > > > On Thu, May 07, 2026 at 11:21:10AM +0000, Yonatan Nachum wrote:
> > > > > From: Michael Margolin <mrgolin@amazon.com>
> > > > > 
> > > > > Change the SQ depth validation to take into account the SQ WQE size.
> > > > > This is needed since when using 128-byte WQE the max SQ depth is cut in
> > > > > half. On create QP command, userspace provides SQ ring size which is SQ
> > > > > depth X WQE size so we can calculate the requested WQE size in the
> > > > > kernel.
> > > > > 
> > > > > Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
> > > > > Reviewed-by: Michael Margolin <mrgolin@amazon.com>
> > > > > Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
> > > > > ---
> > > > >  drivers/infiniband/hw/efa/efa_verbs.c | 39 ++++++++++++++++++---------
> > > > >  1 file changed, 27 insertions(+), 12 deletions(-)
> > > > 
> > > > Please add Fixes line.
> > > > 
> > > > Thanks
> > > 
> > > There is no Fixes tag as this is not a bug fix. The existing validation
> > > works but is overly permissive — it doesn't account for WQE size when
> > > checking max SQ depth. Without it, the device would reject the request
> > > downstream. This patch tightens the validation to fail early in the
> > > kernel.
> > 
> > So why do we need kernel patch after all?
> > 
> > Thanks
> 
> The driver already validates max_send_wr against max_sq_depth — this
> patch just makes that check accurate for the 128-byte WQE case. This
> also gives better error reporting as opposed to device failure.

We seem to be going in circles. You stated that no Fixes tag is needed
and that the previous code behaved correctly. However, as justification
for the change, you described it as providing more accurate and improved
reporting, which effectively sounds like a fix to me.

Thanks