From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- include/net/hwbm.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/net/hwbm.h (limited to 'include/net/hwbm.h') diff --git a/include/net/hwbm.h b/include/net/hwbm.h new file mode 100644 index 000000000..bdbe91c60 --- /dev/null +++ b/include/net/hwbm.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _HWBM_H +#define _HWBM_H + +#include + +struct hwbm_pool { + /* Capacity of the pool */ + int size; + /* Size of the buffers managed */ + int frag_size; + /* Number of buffers currently used by this pool */ + int buf_num; + /* constructor called during allocation */ + int (*construct)(struct hwbm_pool *bm_pool, void *buf); + /* protect access to the buffer counter*/ + struct mutex buf_lock; + /* private data */ + void *priv; +}; +#ifdef CONFIG_HWBM +void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf); +int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp); +int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num); +#else +static inline void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {} + +static inline int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) +{ return 0; } + +static inline int hwbm_pool_add(struct hwbm_pool *bm_pool, + unsigned int buf_num) +{ return 0; } +#endif /* CONFIG_HWBM */ +#endif /* _HWBM_H */ -- cgit v1.3.1