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/simd.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 include/asm-generic/simd.h (limited to 'include/asm-generic/simd.h') diff --git a/include/asm-generic/simd.h b/include/asm-generic/simd.h new file mode 100644 index 000000000..70c8716ad --- /dev/null +++ b/include/asm-generic/simd.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_SIMD_H +#define _ASM_GENERIC_SIMD_H + +#include +#include +#include +#include + +/* + * may_use_simd - whether it is allowable at this time to issue SIMD + * instructions or access the SIMD register file + * + * As architectures typically don't preserve the SIMD register file when + * taking an interrupt, !in_interrupt() should be a reasonable default. + */ +static __must_check inline bool may_use_simd(void) +{ + return !in_interrupt(); +} + +#endif /* _ASM_GENERIC_SIMD_H */ -- cgit v1.3.1