linux-rdma.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH rdma-next 0/2] Extend UAR to have DevX UID
@ 2021-09-14 23:11 Leon Romanovsky
  2021-09-14 23:11 ` [PATCH mlx5-next 1/2] net/mlx5: Add uid field to UAR allocation structures Leon Romanovsky
  2021-09-14 23:11 ` [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID Leon Romanovsky
  0 siblings, 2 replies; 5+ messages in thread
From: Leon Romanovsky @ 2021-09-14 23:11 UTC (permalink / raw)
  To: Doug Ledford, Jason Gunthorpe
  Cc: Leon Romanovsky, linux-rdma, Meir Lichtinger, netdev,
	Saeed Mahameed, Yishai Hadas

From: Leon Romanovsky <leonro@nvidia.com>

Hi,

This is short series from Meir that adds DevX UID to the UAR.

Thanks

Meir Lichtinger (2):
  net/mlx5: Add uid field to UAR allocation structures
  IB/mlx5: Enable UAR to have DevX UID

 drivers/infiniband/hw/mlx5/cmd.c  | 24 ++++++++++++++
 drivers/infiniband/hw/mlx5/cmd.h  |  2 ++
 drivers/infiniband/hw/mlx5/main.c | 55 +++++++++++++++++--------------
 include/linux/mlx5/mlx5_ifc.h     |  4 +--
 4 files changed, 59 insertions(+), 26 deletions(-)

-- 
2.31.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH mlx5-next 1/2] net/mlx5: Add uid field to UAR allocation structures
  2021-09-14 23:11 [PATCH rdma-next 0/2] Extend UAR to have DevX UID Leon Romanovsky
@ 2021-09-14 23:11 ` Leon Romanovsky
  2021-09-14 23:11 ` [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID Leon Romanovsky
  1 sibling, 0 replies; 5+ messages in thread
From: Leon Romanovsky @ 2021-09-14 23:11 UTC (permalink / raw)
  To: Doug Ledford, Jason Gunthorpe
  Cc: Meir Lichtinger, linux-kernel, linux-rdma, netdev,
	Saeed Mahameed, Yishai Hadas

From: Meir Lichtinger <meirl@nvidia.com>

Add uid field to mlx5_ifc_alloc_uar_in_bits and
mlx5_ifc_dealloc_uar_out_bits structs.

This field will be used by FW to manage UAR according to uid.

Signed-off-by: Meir Lichtinger <meirl@nvidia.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 include/linux/mlx5/mlx5_ifc.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h
index 52e5baad3b93..4a7e6914ed9b 100644
--- a/include/linux/mlx5/mlx5_ifc.h
+++ b/include/linux/mlx5/mlx5_ifc.h
@@ -7573,7 +7573,7 @@ struct mlx5_ifc_dealloc_uar_out_bits {
 
 struct mlx5_ifc_dealloc_uar_in_bits {
 	u8         opcode[0x10];
-	u8         reserved_at_10[0x10];
+	u8         uid[0x10];
 
 	u8         reserved_at_20[0x10];
 	u8         op_mod[0x10];
@@ -8420,7 +8420,7 @@ struct mlx5_ifc_alloc_uar_out_bits {
 
 struct mlx5_ifc_alloc_uar_in_bits {
 	u8         opcode[0x10];
-	u8         reserved_at_10[0x10];
+	u8         uid[0x10];
 
 	u8         reserved_at_20[0x10];
 	u8         op_mod[0x10];
-- 
2.31.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID
  2021-09-14 23:11 [PATCH rdma-next 0/2] Extend UAR to have DevX UID Leon Romanovsky
  2021-09-14 23:11 ` [PATCH mlx5-next 1/2] net/mlx5: Add uid field to UAR allocation structures Leon Romanovsky
@ 2021-09-14 23:11 ` Leon Romanovsky
  2021-09-15 13:47   ` Jason Gunthorpe
  1 sibling, 1 reply; 5+ messages in thread
From: Leon Romanovsky @ 2021-09-14 23:11 UTC (permalink / raw)
  To: Doug Ledford, Jason Gunthorpe
  Cc: Meir Lichtinger, linux-kernel, linux-rdma, netdev,
	Saeed Mahameed, Yishai Hadas

From: Meir Lichtinger <meirl@nvidia.com>

UID field was added to alloc_uar and dealloc_uar PRM command, to specify
DevX UID for UAR. This change enables firmware validating user access to
its own UAR resources.

For the kernel allocated UARs the UID will stay 0 as of today.

Signed-off-by: Meir Lichtinger <meirl@nvidia.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/hw/mlx5/cmd.c  | 24 ++++++++++++++
 drivers/infiniband/hw/mlx5/cmd.h  |  2 ++
 drivers/infiniband/hw/mlx5/main.c | 55 +++++++++++++++++--------------
 3 files changed, 57 insertions(+), 24 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/cmd.c b/drivers/infiniband/hw/mlx5/cmd.c
index a8db8a051170..0fe3c4ceec43 100644
--- a/drivers/infiniband/hw/mlx5/cmd.c
+++ b/drivers/infiniband/hw/mlx5/cmd.c
@@ -206,3 +206,27 @@ int mlx5_cmd_mad_ifc(struct mlx5_core_dev *dev, const void *inb, void *outb,
 	kfree(in);
 	return err;
 }
+
+int mlx5_ib_cmd_uar_alloc(struct mlx5_core_dev *dev, u32 *uarn, u16 uid)
+{
+	u32 out[MLX5_ST_SZ_DW(alloc_uar_out)] = {};
+	u32 in[MLX5_ST_SZ_DW(alloc_uar_in)] = {};
+	int err;
+
+	MLX5_SET(alloc_uar_in, in, opcode, MLX5_CMD_OP_ALLOC_UAR);
+	MLX5_SET(alloc_uar_in, in, uid, uid);
+	err = mlx5_cmd_exec_inout(dev, alloc_uar, in, out);
+	if (!err)
+		*uarn = MLX5_GET(alloc_uar_out, out, uar);
+	return err;
+}
+
+int mlx5_ib_cmd_uar_dealloc(struct mlx5_core_dev *dev, u32 uarn, u16 uid)
+{
+	u32 in[MLX5_ST_SZ_DW(dealloc_uar_in)] = {};
+
+	MLX5_SET(dealloc_uar_in, in, opcode, MLX5_CMD_OP_DEALLOC_UAR);
+	MLX5_SET(dealloc_uar_in, in, uar, uarn);
+	MLX5_SET(dealloc_uar_in, in, uid, uid);
+	return mlx5_cmd_exec_in(dev, dealloc_uar, in);
+}
diff --git a/drivers/infiniband/hw/mlx5/cmd.h b/drivers/infiniband/hw/mlx5/cmd.h
index 66c96292ed43..a008938e52f4 100644
--- a/drivers/infiniband/hw/mlx5/cmd.h
+++ b/drivers/infiniband/hw/mlx5/cmd.h
@@ -57,4 +57,6 @@ int mlx5_cmd_xrcd_alloc(struct mlx5_core_dev *dev, u32 *xrcdn, u16 uid);
 int mlx5_cmd_xrcd_dealloc(struct mlx5_core_dev *dev, u32 xrcdn, u16 uid);
 int mlx5_cmd_mad_ifc(struct mlx5_core_dev *dev, const void *inb, void *outb,
 		     u16 opmod, u8 port);
+int mlx5_ib_cmd_uar_alloc(struct mlx5_core_dev *dev, u32 *uarn, u16 uid);
+int mlx5_ib_cmd_uar_dealloc(struct mlx5_core_dev *dev, u32 uarn, u16 uid);
 #endif /* MLX5_IB_CMD_H */
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 8664bcf6d3f5..a6dcdbbc242f 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1643,7 +1643,8 @@ static int allocate_uars(struct mlx5_ib_dev *dev, struct mlx5_ib_ucontext *conte
 
 	bfregi = &context->bfregi;
 	for (i = 0; i < bfregi->num_static_sys_pages; i++) {
-		err = mlx5_cmd_alloc_uar(dev->mdev, &bfregi->sys_pages[i]);
+		err = mlx5_ib_cmd_uar_alloc(dev->mdev, &bfregi->sys_pages[i],
+					    context->devx_uid);
 		if (err)
 			goto error;
 
@@ -1657,7 +1658,8 @@ static int allocate_uars(struct mlx5_ib_dev *dev, struct mlx5_ib_ucontext *conte
 
 error:
 	for (--i; i >= 0; i--)
-		if (mlx5_cmd_free_uar(dev->mdev, bfregi->sys_pages[i]))
+		if (mlx5_ib_cmd_uar_dealloc(dev->mdev, bfregi->sys_pages[i],
+					    context->devx_uid))
 			mlx5_ib_warn(dev, "failed to free uar %d\n", i);
 
 	return err;
@@ -1673,7 +1675,8 @@ static void deallocate_uars(struct mlx5_ib_dev *dev,
 	for (i = 0; i < bfregi->num_sys_pages; i++)
 		if (i < bfregi->num_static_sys_pages ||
 		    bfregi->sys_pages[i] != MLX5_IB_INVALID_UAR_INDEX)
-			mlx5_cmd_free_uar(dev->mdev, bfregi->sys_pages[i]);
+			mlx5_ib_cmd_uar_dealloc(dev->mdev, bfregi->sys_pages[i],
+						context->devx_uid);
 }
 
 int mlx5_ib_enable_lb(struct mlx5_ib_dev *dev, bool td, bool qp)
@@ -1891,6 +1894,13 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 	if (req.num_low_latency_bfregs > req.total_num_bfregs - 1)
 		return -EINVAL;
 
+	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX) {
+		err = mlx5_ib_devx_create(dev, true);
+		if (err < 0)
+			goto out_ctx;
+		context->devx_uid = err;
+	}
+
 	lib_uar_4k = req.lib_caps & MLX5_LIB_CAP_4K_UAR;
 	lib_uar_dyn = req.lib_caps & MLX5_LIB_CAP_DYN_UAR;
 	bfregi = &context->bfregi;
@@ -1903,7 +1913,7 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 	/* updates req->total_num_bfregs */
 	err = calc_total_bfregs(dev, lib_uar_4k, &req, bfregi);
 	if (err)
-		goto out_ctx;
+		goto out_devx;
 
 	mutex_init(&bfregi->lock);
 	bfregi->lib_uar_4k = lib_uar_4k;
@@ -1911,7 +1921,7 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 				GFP_KERNEL);
 	if (!bfregi->count) {
 		err = -ENOMEM;
-		goto out_ctx;
+		goto out_devx;
 	}
 
 	bfregi->sys_pages = kcalloc(bfregi->num_sys_pages,
@@ -1927,17 +1937,10 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 		goto out_sys_pages;
 
 uar_done:
-	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX) {
-		err = mlx5_ib_devx_create(dev, true);
-		if (err < 0)
-			goto out_uars;
-		context->devx_uid = err;
-	}
-
 	err = mlx5_ib_alloc_transport_domain(dev, &context->tdn,
 					     context->devx_uid);
 	if (err)
-		goto out_devx;
+		goto out_uars;
 
 	INIT_LIST_HEAD(&context->db_page_list);
 	mutex_init(&context->db_page_mutex);
@@ -1972,9 +1975,6 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 
 out_mdev:
 	mlx5_ib_dealloc_transport_domain(dev, context->tdn, context->devx_uid);
-out_devx:
-	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX)
-		mlx5_ib_devx_destroy(dev, context->devx_uid);
 
 out_uars:
 	deallocate_uars(dev, context);
@@ -1985,6 +1985,10 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 out_count:
 	kfree(bfregi->count);
 
+out_devx:
+	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX)
+		mlx5_ib_devx_destroy(dev, context->devx_uid);
+
 out_ctx:
 	return err;
 }
@@ -2021,12 +2025,12 @@ static void mlx5_ib_dealloc_ucontext(struct ib_ucontext *ibcontext)
 	bfregi = &context->bfregi;
 	mlx5_ib_dealloc_transport_domain(dev, context->tdn, context->devx_uid);
 
-	if (context->devx_uid)
-		mlx5_ib_devx_destroy(dev, context->devx_uid);
-
 	deallocate_uars(dev, context);
 	kfree(bfregi->sys_pages);
 	kfree(bfregi->count);
+
+	if (context->devx_uid)
+		mlx5_ib_devx_destroy(dev, context->devx_uid);
 }
 
 static phys_addr_t uar_index2pfn(struct mlx5_ib_dev *dev,
@@ -2119,6 +2123,7 @@ static void mlx5_ib_mmap_free(struct rdma_user_mmap_entry *entry)
 	struct mlx5_user_mmap_entry *mentry = to_mmmap(entry);
 	struct mlx5_ib_dev *dev = to_mdev(entry->ucontext->device);
 	struct mlx5_var_table *var_table = &dev->var_table;
+	struct mlx5_ib_ucontext *context = to_mucontext(entry->ucontext);
 
 	switch (mentry->mmap_flag) {
 	case MLX5_IB_MMAP_TYPE_MEMIC:
@@ -2133,7 +2138,8 @@ static void mlx5_ib_mmap_free(struct rdma_user_mmap_entry *entry)
 		break;
 	case MLX5_IB_MMAP_TYPE_UAR_WC:
 	case MLX5_IB_MMAP_TYPE_UAR_NC:
-		mlx5_cmd_free_uar(dev->mdev, mentry->page_idx);
+		mlx5_ib_cmd_uar_dealloc(dev->mdev, mentry->page_idx,
+					context->devx_uid);
 		kfree(mentry);
 		break;
 	default:
@@ -2211,7 +2217,8 @@ static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,
 		bfregi->count[bfreg_dyn_idx]++;
 		mutex_unlock(&bfregi->lock);
 
-		err = mlx5_cmd_alloc_uar(dev->mdev, &uar_index);
+		err = mlx5_ib_cmd_uar_alloc(dev->mdev, &uar_index,
+					    context->devx_uid);
 		if (err) {
 			mlx5_ib_warn(dev, "UAR alloc failed\n");
 			goto free_bfreg;
@@ -2240,7 +2247,7 @@ static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,
 	if (!dyn_uar)
 		return err;
 
-	mlx5_cmd_free_uar(dev->mdev, idx);
+	mlx5_ib_cmd_uar_dealloc(dev->mdev, idx, context->devx_uid);
 
 free_bfreg:
 	mlx5_ib_free_bfreg(dev, bfregi, bfreg_dyn_idx);
@@ -3489,7 +3496,7 @@ alloc_uar_entry(struct mlx5_ib_ucontext *c,
 		return ERR_PTR(-ENOMEM);
 
 	dev = to_mdev(c->ibucontext.device);
-	err = mlx5_cmd_alloc_uar(dev->mdev, &uar_index);
+	err = mlx5_ib_cmd_uar_alloc(dev->mdev, &uar_index, c->devx_uid);
 	if (err)
 		goto end;
 
@@ -3507,7 +3514,7 @@ alloc_uar_entry(struct mlx5_ib_ucontext *c,
 	return entry;
 
 err_insert:
-	mlx5_cmd_free_uar(dev->mdev, uar_index);
+	mlx5_ib_cmd_uar_dealloc(dev->mdev, uar_index, c->devx_uid);
 end:
 	kfree(entry);
 	return ERR_PTR(err);
-- 
2.31.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID
  2021-09-14 23:11 ` [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID Leon Romanovsky
@ 2021-09-15 13:47   ` Jason Gunthorpe
  2021-09-20 13:21     ` Leon Romanovsky
  0 siblings, 1 reply; 5+ messages in thread
From: Jason Gunthorpe @ 2021-09-15 13:47 UTC (permalink / raw)
  To: Leon Romanovsky
  Cc: Doug Ledford, Meir Lichtinger, linux-kernel, linux-rdma, netdev,
	Saeed Mahameed, Yishai Hadas

On Wed, Sep 15, 2021 at 02:11:23AM +0300, Leon Romanovsky wrote:
> From: Meir Lichtinger <meirl@nvidia.com>
> 
> UID field was added to alloc_uar and dealloc_uar PRM command, to specify
> DevX UID for UAR. This change enables firmware validating user access to
> its own UAR resources.
> 
> For the kernel allocated UARs the UID will stay 0 as of today.
> 
> Signed-off-by: Meir Lichtinger <meirl@nvidia.com>
> Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
>  drivers/infiniband/hw/mlx5/cmd.c  | 24 ++++++++++++++
>  drivers/infiniband/hw/mlx5/cmd.h  |  2 ++
>  drivers/infiniband/hw/mlx5/main.c | 55 +++++++++++++++++--------------
>  3 files changed, 57 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/mlx5/cmd.c b/drivers/infiniband/hw/mlx5/cmd.c
> index a8db8a051170..0fe3c4ceec43 100644
> +++ b/drivers/infiniband/hw/mlx5/cmd.c
> @@ -206,3 +206,27 @@ int mlx5_cmd_mad_ifc(struct mlx5_core_dev *dev, const void *inb, void *outb,
>  	kfree(in);
>  	return err;
>  }
> +
> +int mlx5_ib_cmd_uar_alloc(struct mlx5_core_dev *dev, u32 *uarn, u16 uid)
> +{
> +	u32 out[MLX5_ST_SZ_DW(alloc_uar_out)] = {};
> +	u32 in[MLX5_ST_SZ_DW(alloc_uar_in)] = {};
> +	int err;
> +
> +	MLX5_SET(alloc_uar_in, in, opcode, MLX5_CMD_OP_ALLOC_UAR);
> +	MLX5_SET(alloc_uar_in, in, uid, uid);
> +	err = mlx5_cmd_exec_inout(dev, alloc_uar, in, out);
> +	if (!err)
> +		*uarn = MLX5_GET(alloc_uar_out, out, uar);

Success oriented flow:

 if (err)
     return err;
 *uarn = MLX5_GET(alloc_uar_out, out, uar);
 return 0;

And why did we add entirely new functions instead of just adding a uid
argument to the core ones? Or, why doesn't this delete the old core
functions that look unused outside of IB anyhow?

Jason

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID
  2021-09-15 13:47   ` Jason Gunthorpe
@ 2021-09-20 13:21     ` Leon Romanovsky
  0 siblings, 0 replies; 5+ messages in thread
From: Leon Romanovsky @ 2021-09-20 13:21 UTC (permalink / raw)
  To: Jason Gunthorpe
  Cc: Doug Ledford, Meir Lichtinger, linux-kernel, linux-rdma, netdev,
	Saeed Mahameed, Yishai Hadas

On Wed, Sep 15, 2021 at 10:47:53AM -0300, Jason Gunthorpe wrote:
> On Wed, Sep 15, 2021 at 02:11:23AM +0300, Leon Romanovsky wrote:
> > From: Meir Lichtinger <meirl@nvidia.com>
> > 
> > UID field was added to alloc_uar and dealloc_uar PRM command, to specify
> > DevX UID for UAR. This change enables firmware validating user access to
> > its own UAR resources.
> > 
> > For the kernel allocated UARs the UID will stay 0 as of today.
> > 
> > Signed-off-by: Meir Lichtinger <meirl@nvidia.com>
> > Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
> > Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> >  drivers/infiniband/hw/mlx5/cmd.c  | 24 ++++++++++++++
> >  drivers/infiniband/hw/mlx5/cmd.h  |  2 ++
> >  drivers/infiniband/hw/mlx5/main.c | 55 +++++++++++++++++--------------
> >  3 files changed, 57 insertions(+), 24 deletions(-)
> > 
> > diff --git a/drivers/infiniband/hw/mlx5/cmd.c b/drivers/infiniband/hw/mlx5/cmd.c
> > index a8db8a051170..0fe3c4ceec43 100644
> > +++ b/drivers/infiniband/hw/mlx5/cmd.c
> > @@ -206,3 +206,27 @@ int mlx5_cmd_mad_ifc(struct mlx5_core_dev *dev, const void *inb, void *outb,
> >  	kfree(in);
> >  	return err;
> >  }
> > +
> > +int mlx5_ib_cmd_uar_alloc(struct mlx5_core_dev *dev, u32 *uarn, u16 uid)
> > +{
> > +	u32 out[MLX5_ST_SZ_DW(alloc_uar_out)] = {};
> > +	u32 in[MLX5_ST_SZ_DW(alloc_uar_in)] = {};
> > +	int err;
> > +
> > +	MLX5_SET(alloc_uar_in, in, opcode, MLX5_CMD_OP_ALLOC_UAR);
> > +	MLX5_SET(alloc_uar_in, in, uid, uid);
> > +	err = mlx5_cmd_exec_inout(dev, alloc_uar, in, out);
> > +	if (!err)
> > +		*uarn = MLX5_GET(alloc_uar_out, out, uar);
> 
> Success oriented flow:
> 
>  if (err)
>      return err;
>  *uarn = MLX5_GET(alloc_uar_out, out, uar);
>  return 0;
> 
> And why did we add entirely new functions instead of just adding a uid
> argument to the core ones? Or, why doesn't this delete the old core
> functions that look unused outside of IB anyhow?

We didn't want to add not-needed for mlx5_core uid field, the rest
comments are valid and I'm sorry that I missed them.

Thanks

> 
> Jason

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2021-09-20 13:21 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-14 23:11 [PATCH rdma-next 0/2] Extend UAR to have DevX UID Leon Romanovsky
2021-09-14 23:11 ` [PATCH mlx5-next 1/2] net/mlx5: Add uid field to UAR allocation structures Leon Romanovsky
2021-09-14 23:11 ` [PATCH rdma-next 2/2] IB/mlx5: Enable UAR to have DevX UID Leon Romanovsky
2021-09-15 13:47   ` Jason Gunthorpe
2021-09-20 13:21     ` Leon Romanovsky

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).