cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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virt.h (3864B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 * Copyright (C) 2012 ARM Ltd.
      4 * Author: Marc Zyngier <marc.zyngier@arm.com>
      5 */
      6
      7#ifndef __ASM__VIRT_H
      8#define __ASM__VIRT_H
      9
     10/*
     11 * The arm64 hcall implementation uses x0 to specify the hcall
     12 * number. A value less than HVC_STUB_HCALL_NR indicates a special
     13 * hcall, such as set vector. Any other value is handled in a
     14 * hypervisor specific way.
     15 *
     16 * The hypercall is allowed to clobber any of the caller-saved
     17 * registers (x0-x18), so it is advisable to use it through the
     18 * indirection of a function call (as implemented in hyp-stub.S).
     19 */
     20
     21/*
     22 * HVC_SET_VECTORS - Set the value of the vbar_el2 register.
     23 *
     24 * @x1: Physical address of the new vector table.
     25 */
     26#define HVC_SET_VECTORS 0
     27
     28/*
     29 * HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine.
     30 */
     31#define HVC_SOFT_RESTART 1
     32
     33/*
     34 * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
     35 */
     36#define HVC_RESET_VECTORS 2
     37
     38/*
     39 * HVC_VHE_RESTART - Upgrade the CPU from EL1 to EL2, if possible
     40 */
     41#define HVC_VHE_RESTART	3
     42
     43/* Max number of HYP stub hypercalls */
     44#define HVC_STUB_HCALL_NR 4
     45
     46/* Error returned when an invalid stub number is passed into x0 */
     47#define HVC_STUB_ERR	0xbadca11
     48
     49#define BOOT_CPU_MODE_EL1	(0xe11)
     50#define BOOT_CPU_MODE_EL2	(0xe12)
     51
     52#ifndef __ASSEMBLY__
     53
     54#include <asm/ptrace.h>
     55#include <asm/sections.h>
     56#include <asm/sysreg.h>
     57#include <asm/cpufeature.h>
     58
     59/*
     60 * __boot_cpu_mode records what mode CPUs were booted in.
     61 * A correctly-implemented bootloader must start all CPUs in the same mode:
     62 * In this case, both 32bit halves of __boot_cpu_mode will contain the
     63 * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
     64 *
     65 * Should the bootloader fail to do this, the two values will be different.
     66 * This allows the kernel to flag an error when the secondaries have come up.
     67 */
     68extern u32 __boot_cpu_mode[2];
     69
     70#define ARM64_VECTOR_TABLE_LEN	SZ_2K
     71
     72void __hyp_set_vectors(phys_addr_t phys_vector_base);
     73void __hyp_reset_vectors(void);
     74
     75DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
     76
     77/* Reports the availability of HYP mode */
     78static inline bool is_hyp_mode_available(void)
     79{
     80	/*
     81	 * If KVM protected mode is initialized, all CPUs must have been booted
     82	 * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
     83	 */
     84	if (IS_ENABLED(CONFIG_KVM) &&
     85	    static_branch_likely(&kvm_protected_mode_initialized))
     86		return true;
     87
     88	return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
     89		__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
     90}
     91
     92/* Check if the bootloader has booted CPUs in different modes */
     93static inline bool is_hyp_mode_mismatched(void)
     94{
     95	/*
     96	 * If KVM protected mode is initialized, all CPUs must have been booted
     97	 * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
     98	 */
     99	if (IS_ENABLED(CONFIG_KVM) &&
    100	    static_branch_likely(&kvm_protected_mode_initialized))
    101		return false;
    102
    103	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
    104}
    105
    106static inline bool is_kernel_in_hyp_mode(void)
    107{
    108	return read_sysreg(CurrentEL) == CurrentEL_EL2;
    109}
    110
    111static __always_inline bool has_vhe(void)
    112{
    113	/*
    114	 * Code only run in VHE/NVHE hyp context can assume VHE is present or
    115	 * absent. Otherwise fall back to caps.
    116	 * This allows the compiler to discard VHE-specific code from the
    117	 * nVHE object, reducing the number of external symbol references
    118	 * needed to link.
    119	 */
    120	if (is_vhe_hyp_code())
    121		return true;
    122	else if (is_nvhe_hyp_code())
    123		return false;
    124	else
    125		return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN);
    126}
    127
    128static __always_inline bool is_protected_kvm_enabled(void)
    129{
    130	if (is_vhe_hyp_code())
    131		return false;
    132	else
    133		return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE);
    134}
    135
    136static inline bool is_hyp_nvhe(void)
    137{
    138	return is_hyp_mode_available() && !is_kernel_in_hyp_mode();
    139}
    140
    141#endif /* __ASSEMBLY__ */
    142
    143#endif /* ! __ASM__VIRT_H */