Files
linux/arch/arm64/include/asm/cpu.h
T
Fuad Tabba 5445d64199 arm64: Don't read GMID_EL1 when MTE is disabled
__cpuinfo_store_cpu() gates the GMID_EL1 read on the raw
ID_AA64PFR1_EL1, so it reads the register even when the kernel has
disabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5
in that case, and pKVM injects an UNDEF the host cannot handle:

  Internal error: Oops - Undefined instruction: 0000000002000000 [#1]  SMP
  pc : __cpuinfo_store_cpu+0xf4/0x264
  Kernel panic - not syncing: Attempted to kill the idle task!

Only pKVM reaches it, and only after a CPU is offlined and brought back
online: its CPU_ON relay sets the host HCR before the CPU enters EL1,
while plain nVHE sets it at CPUHP_AP_KVM_ONLINE.

Gate the read on the CPU's own ID_AA64PFR1_EL1 with the command-line
override applied, and on CONFIG_ARM64_MTE, which no register reflects.
The boot CPU stores its registers before init_cpu_features() strips an
unsafe override, so clamp against the hardware value here too.

Fixes: f35abcbb8a ("KVM: arm64: Trap MTE access and discovery when MTE is disabled")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-03 13:03:23 +00:00

84 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014 ARM Ltd.
*/
#ifndef __ASM_CPU_H
#define __ASM_CPU_H
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/percpu.h>
/*
* Records attributes of an individual CPU.
*/
struct cpuinfo_32bit {
u32 reg_id_dfr0;
u32 reg_id_dfr1;
u32 reg_id_isar0;
u32 reg_id_isar1;
u32 reg_id_isar2;
u32 reg_id_isar3;
u32 reg_id_isar4;
u32 reg_id_isar5;
u32 reg_id_isar6;
u32 reg_id_mmfr0;
u32 reg_id_mmfr1;
u32 reg_id_mmfr2;
u32 reg_id_mmfr3;
u32 reg_id_mmfr4;
u32 reg_id_mmfr5;
u32 reg_id_pfr0;
u32 reg_id_pfr1;
u32 reg_id_pfr2;
u32 reg_mvfr0;
u32 reg_mvfr1;
u32 reg_mvfr2;
};
struct cpuinfo_arm64 {
struct kobject kobj;
u64 reg_ctr;
u64 reg_cntfrq;
u64 reg_dczid;
u64 reg_midr;
u64 reg_revidr;
u64 reg_aidr;
u64 reg_gmid;
u64 reg_smidr;
u64 reg_mpamidr;
u64 reg_id_aa64dfr0;
u64 reg_id_aa64dfr1;
u64 reg_id_aa64isar0;
u64 reg_id_aa64isar1;
u64 reg_id_aa64isar2;
u64 reg_id_aa64isar3;
u64 reg_id_aa64mmfr0;
u64 reg_id_aa64mmfr1;
u64 reg_id_aa64mmfr2;
u64 reg_id_aa64mmfr3;
u64 reg_id_aa64mmfr4;
u64 reg_id_aa64pfr0;
u64 reg_id_aa64pfr1;
u64 reg_id_aa64pfr2;
u64 reg_id_aa64zfr0;
u64 reg_id_aa64smfr0;
u64 reg_id_aa64fpfr0;
struct cpuinfo_32bit aarch32;
};
DECLARE_PER_CPU(struct cpuinfo_arm64, cpu_data);
void cpuinfo_store_cpu(void);
void __init cpuinfo_store_boot_cpu(void);
void __init init_cpu_features(struct cpuinfo_arm64 *info);
void update_cpu_features(int cpu, struct cpuinfo_arm64 *info,
struct cpuinfo_arm64 *boot);
bool gmid_el1_accessible(const struct cpuinfo_arm64 *info);
#endif /* __ASM_CPU_H */