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Diffstat (limited to 'arch/arm64/include/asm/virt.h')
| -rw-r--r-- | arch/arm64/include/asm/virt.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h new file mode 100644 index 000000000..4eb601e7d --- /dev/null +++ b/arch/arm64/include/asm/virt.h @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 ARM Ltd. + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#ifndef __ASM__VIRT_H +#define __ASM__VIRT_H + +/* + * The arm64 hcall implementation uses x0 to specify the hcall + * number. A value less than HVC_STUB_HCALL_NR indicates a special + * hcall, such as set vector. Any other value is handled in a + * hypervisor specific way. + * + * The hypercall is allowed to clobber any of the caller-saved + * registers (x0-x18), so it is advisable to use it through the + * indirection of a function call (as implemented in hyp-stub.S). + */ + +/* + * HVC_SET_VECTORS - Set the value of the vbar_el2 register. + * + * @x1: Physical address of the new vector table. + */ +#define HVC_SET_VECTORS 0 + +/* + * HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine. + */ +#define HVC_SOFT_RESTART 1 + +/* + * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs + */ +#define HVC_RESET_VECTORS 2 + +/* + * HVC_FINALISE_EL2 - Upgrade the CPU from EL1 to EL2, if possible + */ +#define HVC_FINALISE_EL2 3 + +/* Max number of HYP stub hypercalls */ +#define HVC_STUB_HCALL_NR 4 + +/* Error returned when an invalid stub number is passed into x0 */ +#define HVC_STUB_ERR 0xbadca11 + +#define BOOT_CPU_MODE_EL1 (0xe11) +#define BOOT_CPU_MODE_EL2 (0xe12) + +/* + * Flags returned together with the boot mode, but not preserved in + * __boot_cpu_mode. Used by the idreg override code to work out the + * boot state. + */ +#define BOOT_CPU_FLAG_E2H BIT_ULL(32) + +#ifndef __ASSEMBLY__ + +#include <asm/ptrace.h> +#include <asm/sections.h> +#include <asm/sysreg.h> +#include <asm/cpufeature.h> + +/* + * __boot_cpu_mode records what mode CPUs were booted in. + * A correctly-implemented bootloader must start all CPUs in the same mode: + * In this case, both 32bit halves of __boot_cpu_mode will contain the + * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2). + * + * Should the bootloader fail to do this, the two values will be different. + * This allows the kernel to flag an error when the secondaries have come up. + */ +extern u32 __boot_cpu_mode[2]; + +#define ARM64_VECTOR_TABLE_LEN SZ_2K + +void __hyp_set_vectors(phys_addr_t phys_vector_base); +void __hyp_reset_vectors(void); + +DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); + +/* Reports the availability of HYP mode */ +static inline bool is_hyp_mode_available(void) +{ + /* + * If KVM protected mode is initialized, all CPUs must have been booted + * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1. + */ + if (IS_ENABLED(CONFIG_KVM) && + static_branch_likely(&kvm_protected_mode_initialized)) + return true; + + return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 && + __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2); +} + +/* Check if the bootloader has booted CPUs in different modes */ +static inline bool is_hyp_mode_mismatched(void) +{ + /* + * If KVM protected mode is initialized, all CPUs must have been booted + * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1. + */ + if (IS_ENABLED(CONFIG_KVM) && + static_branch_likely(&kvm_protected_mode_initialized)) + return false; + + return __boot_cpu_mode[0] != __boot_cpu_mode[1]; +} + +static inline bool is_kernel_in_hyp_mode(void) +{ + return read_sysreg(CurrentEL) == CurrentEL_EL2; +} + +static __always_inline bool has_vhe(void) +{ + /* + * Code only run in VHE/NVHE hyp context can assume VHE is present or + * absent. Otherwise fall back to caps. + * This allows the compiler to discard VHE-specific code from the + * nVHE object, reducing the number of external symbol references + * needed to link. + */ + if (is_vhe_hyp_code()) + return true; + else if (is_nvhe_hyp_code()) + return false; + else + return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN); +} + +static __always_inline bool is_protected_kvm_enabled(void) +{ + if (is_vhe_hyp_code()) + return false; + else + return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE); +} + +static inline bool is_hyp_nvhe(void) +{ + return is_hyp_mode_available() && !is_kernel_in_hyp_mode(); +} + +#endif /* __ASSEMBLY__ */ + +#endif /* ! __ASM__VIRT_H */ |