[PATCH 6.12 060/460] xdp: register system page pool as an XDP memory model

Greg Kroah-Hartman
2026-03-23T14:17:25Z

6.12-stable review patch. If anyone has any objections, please let me know.

------------------

From: Toke Høiland-Jørgensen <toke@redhat.com>

[ Upstream commit e77d9aee951341119be16a991fcfc76d1154d22a ]

To make the system page pool usable as a source for allocating XDP
frames, we need to register it with xdp_reg_mem_model(), so that page
return works correctly. This is done in preparation for using the system
page_pool to convert XDP_PASS XSk frames to skbs; for the same reason,
make the per-cpu variable non-static so we can access it from other
source files as well (but w/o exporting).

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20241203173733.3181246-7-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/netdevice.h | 1 +
net/core/dev.c | 10 +++++++++-
2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3699c43731ccf..d5215f23f2b99 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3256,6 +3256,7 @@ struct softnet_data {
};

DECLARE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
+DECLARE_PER_CPU(struct page_pool *, system_page_pool);

#ifndef CONFIG_PREEMPT_RT
static inline int dev_recursion_level(void)
diff --git a/net/core/dev.c b/net/core/dev.c
index a855cee5e5aeb..336257b515f04 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -460,7 +460,7 @@ EXPORT_PER_CPU_SYMBOL(softnet_data);
* PP consumers must pay attention to run APIs in the appropriate context
* (e.g. NAPI context).
*/
-static DEFINE_PER_CPU(struct page_pool *, system_page_pool);
+DEFINE_PER_CPU(struct page_pool *, system_page_pool);

#ifdef CONFIG_LOCKDEP
/*
@@ -12225,11 +12225,18 @@ static int net_page_pool_create(int cpuid)
.nid = cpu_to_mem(cpuid),
};
struct page_pool *pp_ptr;
+ int err;

pp_ptr = page_pool_create_percpu(&page_pool_params, cpuid);
if (IS_ERR(pp_ptr))
return -ENOMEM;

+ err = xdp_reg_page_pool(pp_ptr);
+ if (err) {
+ page_pool_destroy(pp_ptr);
+ return err;
+ }
+
per_cpu(system_page_pool, cpuid) = pp_ptr;
#endif
return 0;
@@ -12363,6 +12370,7 @@ static int __init net_dev_init(void)
if (!pp_ptr)
continue;

+ xdp_unreg_page_pool(pp_ptr);
page_pool_destroy(pp_ptr);
per_cpu(system_page_pool, i) = NULL;
}
--
2.51.0