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/asm-generic/pgtable-nop4d.h | 58 +++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 include/asm-generic/pgtable-nop4d.h (limited to 'include/asm-generic/pgtable-nop4d.h') diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h new file mode 100644 index 000000000..89c21f84c --- /dev/null +++ b/include/asm-generic/pgtable-nop4d.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _PGTABLE_NOP4D_H +#define _PGTABLE_NOP4D_H + +#ifndef __ASSEMBLER__ + +#define __PAGETABLE_P4D_FOLDED 1 + +typedef struct { pgd_t pgd; } p4d_t; + +#define P4D_SHIFT PGDIR_SHIFT +#define PTRS_PER_P4D 1 +#define P4D_SIZE (1UL << P4D_SHIFT) +#define P4D_MASK (~(P4D_SIZE-1)) + +/* + * The "pgd_xxx()" functions here are trivial for a folded two-level + * setup: the p4d is never bad, and a p4d always exists (as it's folded + * into the pgd entry) + */ +static inline int pgd_none(pgd_t pgd) { return 0; } +static inline int pgd_bad(pgd_t pgd) { return 0; } +static inline int pgd_present(pgd_t pgd) { return 1; } +static inline void pgd_clear(pgd_t *pgd) { } +#define p4d_ERROR(p4d) (pgd_ERROR((p4d).pgd)) + +#define pgd_populate(mm, pgd, p4d) do { } while (0) +#define pgd_populate_safe(mm, pgd, p4d) do { } while (0) +/* + * (p4ds are folded into pgds so this doesn't get actually called, + * but the define is needed for a generic inline function.) + */ +#define set_pgd(pgdptr, pgdval) set_p4d((p4d_t *)(pgdptr), (p4d_t) { pgdval }) + +static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address) +{ + return (p4d_t *)pgd; +} + +#define p4d_val(x) (pgd_val((x).pgd)) +#define __p4d(x) ((p4d_t) { __pgd(x) }) + +#define pgd_page(pgd) (p4d_page((p4d_t){ pgd })) +#define pgd_page_vaddr(pgd) ((unsigned long)(p4d_pgtable((p4d_t){ pgd }))) + +/* + * allocating and freeing a p4d is trivial: the 1-entry p4d is + * inside the pgd, so has no extra memory associated with it. + */ +#define p4d_alloc_one(mm, address) NULL +#define p4d_free(mm, x) do { } while (0) +#define p4d_free_tlb(tlb, x, a) do { } while (0) + +#undef p4d_addr_end +#define p4d_addr_end(addr, end) (end) + +#endif /* __ASSEMBLER__ */ +#endif /* _PGTABLE_NOP4D_H */ -- cgit v1.3.1