[ndctl PATCH] cxl/list: apply bus and port filters to anonymous memdevs

[ndctl PATCH] cxl/list: apply bus and port filters to anonymous memdevs

[Alison Schofield]

Anonymous memdevs are disabled memdevs that do not nest in the
topology output and are reported separately in the "anon memdevs"
array.

A user reports that cxl list -M -i with a port filter may return
anonymous memdevs that are not part of the selected port. In this
case, QEMU-defined disabled memdevs were returned in a query of a
cxl_test bus port.

The issue has two parts. First, util_cxl_memdev_filter_by_port() does 
not properly constrain bus-filtered queries. It treats the bus name
as a port identifier, allowing memdevs from other buses to match.

Second, cxl_filter_walk() collects anonymous memdevs in a global
pre-pass without applying decoder, bus, or port filters, so disabled
memdevs outside the requested scope are included.

Update util_cxl_memdev_filter_by_port() to limit the search to the
selected bus and match ports only within that bus. Apply decoder and
bus/port filtering to anonymous memdevs so they follow the same rules
as other memdev listings.

Found with CXL unit test cxl-topology.sh

Reported-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 cxl/filter.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/cxl/filter.c b/cxl/filter.c
index 8c7dc6e31701..5d634d3b2512 100644
--- a/cxl/filter.c
+++ b/cxl/filter.c
@@ -615,12 +615,12 @@ util_cxl_memdev_filter_by_port(struct cxl_memdev *memdev, const char *bus_ident,
 		struct cxl_port *port, *top;
 
 		port = cxl_bus_get_port(bus);
-		if (util_cxl_bus_filter(bus, bus_ident))
-			if (__memdev_filter_by_port(memdev, port,
-						    cxl_bus_get_devname(bus)))
-				return memdev;
+
+		if (!util_cxl_bus_filter(bus, bus_ident))
+			continue;
 		if (__memdev_filter_by_port(memdev, port, port_ident))
-				return memdev;
+			return memdev;
+
 		top = port;
 		cxl_port_foreach_all(top, port)
 			if (__memdev_filter_by_port(memdev, port, port_ident))
@@ -1125,6 +1125,12 @@ struct json_object *cxl_filter_walk(struct cxl_ctx *ctx,
 		if (!util_cxl_memdev_filter(memdev, p->memdev_filter,
 					    p->serial_filter))
 			continue;
+		if (!util_cxl_memdev_filter_by_decoder(memdev,
+						       p->decoder_filter))
+			continue;
+		if (!util_cxl_memdev_filter_by_port(memdev, p->bus_filter,
+						    p->port_filter))
+			continue;
 		if (cxl_memdev_is_enabled(memdev))
 			continue;
 		if (!p->idle)
-- 
2.37.3

Re: [ndctl PATCH] cxl/list: apply bus and port filters to anonymous memdevs

[Dave Jiang]

On 4/10/26 6:13 PM, Alison Schofield wrote:
> Anonymous memdevs are disabled memdevs that do not nest in the
> topology output and are reported separately in the "anon memdevs"
> array.
> 
> A user reports that cxl list -M -i with a port filter may return
> anonymous memdevs that are not part of the selected port. In this
> case, QEMU-defined disabled memdevs were returned in a query of a
> cxl_test bus port.
> 
> The issue has two parts. First, util_cxl_memdev_filter_by_port() does 
> not properly constrain bus-filtered queries. It treats the bus name
> as a port identifier, allowing memdevs from other buses to match.
> 
> Second, cxl_filter_walk() collects anonymous memdevs in a global
> pre-pass without applying decoder, bus, or port filters, so disabled
> memdevs outside the requested scope are included.
> 
> Update util_cxl_memdev_filter_by_port() to limit the search to the
> selected bus and match ports only within that bus. Apply decoder and
> bus/port filtering to anonymous memdevs so they follow the same rules
> as other memdev listings.
> 
> Found with CXL unit test cxl-topology.sh
> 
> Reported-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

Thanks for the quick fix.

> ---
>  cxl/filter.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/cxl/filter.c b/cxl/filter.c
> index 8c7dc6e31701..5d634d3b2512 100644
> --- a/cxl/filter.c
> +++ b/cxl/filter.c
> @@ -615,12 +615,12 @@ util_cxl_memdev_filter_by_port(struct cxl_memdev *memdev, const char *bus_ident,
>  		struct cxl_port *port, *top;
>  
>  		port = cxl_bus_get_port(bus);
> -		if (util_cxl_bus_filter(bus, bus_ident))
> -			if (__memdev_filter_by_port(memdev, port,
> -						    cxl_bus_get_devname(bus)))
> -				return memdev;
> +
> +		if (!util_cxl_bus_filter(bus, bus_ident))
> +			continue;
>  		if (__memdev_filter_by_port(memdev, port, port_ident))
> -				return memdev;
> +			return memdev;
> +
>  		top = port;
>  		cxl_port_foreach_all(top, port)
>  			if (__memdev_filter_by_port(memdev, port, port_ident))
> @@ -1125,6 +1125,12 @@ struct json_object *cxl_filter_walk(struct cxl_ctx *ctx,
>  		if (!util_cxl_memdev_filter(memdev, p->memdev_filter,
>  					    p->serial_filter))
>  			continue;
> +		if (!util_cxl_memdev_filter_by_decoder(memdev,
> +						       p->decoder_filter))
> +			continue;
> +		if (!util_cxl_memdev_filter_by_port(memdev, p->bus_filter,
> +						    p->port_filter))
> +			continue;
>  		if (cxl_memdev_is_enabled(memdev))
>  			continue;
>  		if (!p->idle)