xref: /kernel/linux/linux-5.10/arch/arm64/include/asm/kvm_emulate.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * Derived from arch/arm/include/kvm_emulate.h
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#ifndef __ARM64_KVM_EMULATE_H__
#define __ARM64_KVM_EMULATE_H__

#include <linux/kvm_host.h>

#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_hyp.h>
#include <asm/ptrace.h>
#include <asm/cputype.h>
#include <asm/virt.h>

unsigned long *vcpu_reg32(const struct kvm_vcpu *vcpu, u8 reg_num);
unsigned long vcpu_read_spsr32(const struct kvm_vcpu *vcpu);
void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v);

bool kvm_condition_valid32(const struct kvm_vcpu *vcpu);
void kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr);

void kvm_inject_undefined(struct kvm_vcpu *vcpu);
void kvm_inject_vabt(struct kvm_vcpu *vcpu);
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_undef32(struct kvm_vcpu *vcpu);
void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt32(struct kvm_vcpu *vcpu, unsigned long addr);

static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
{
	return !(vcpu->arch.hcr_el2 & HCR_RW);
}

static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
{
	vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
	if (is_kernel_in_hyp_mode())
		vcpu->arch.hcr_el2 |= HCR_E2H;
	if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) {
		/* route synchronous external abort exceptions to EL2 */
		vcpu->arch.hcr_el2 |= HCR_TEA;
		/* trap error record accesses */
		vcpu->arch.hcr_el2 |= HCR_TERR;
	}

	if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) {
		vcpu->arch.hcr_el2 |= HCR_FWB;
	} else {
		/*
		 * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C
		 * get set in SCTLR_EL1 such that we can detect when the guest
		 * MMU gets turned on and do the necessary cache maintenance
		 * then.
		 */
		vcpu->arch.hcr_el2 |= HCR_TVM;
	}

	if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features))
		vcpu->arch.hcr_el2 &= ~HCR_RW;

	/*
	 * TID3: trap feature register accesses that we virtualise.
	 * For now this is conditional, since no AArch32 feature regs
	 * are currently virtualised.
	 */
	if (!vcpu_el1_is_32bit(vcpu))
		vcpu->arch.hcr_el2 |= HCR_TID3;

	if (cpus_have_const_cap(ARM64_MISMATCHED_CACHE_TYPE) ||
	    vcpu_el1_is_32bit(vcpu))
		vcpu->arch.hcr_el2 |= HCR_TID2;
}

static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
{
	return (unsigned long *)&vcpu->arch.hcr_el2;
}

static inline void vcpu_clear_wfx_traps(struct kvm_vcpu *vcpu)
{
	vcpu->arch.hcr_el2 &= ~HCR_TWE;
	if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
	    vcpu->kvm->arch.vgic.nassgireq)
		vcpu->arch.hcr_el2 &= ~HCR_TWI;
	else
		vcpu->arch.hcr_el2 |= HCR_TWI;
}

static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu)
{
	vcpu->arch.hcr_el2 |= HCR_TWE;
	vcpu->arch.hcr_el2 |= HCR_TWI;
}

static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu)
{
	vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
}

static inline void vcpu_ptrauth_disable(struct kvm_vcpu *vcpu)
{
	vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
}

static inline unsigned long vcpu_get_vsesr(struct kvm_vcpu *vcpu)
{
	return vcpu->arch.vsesr_el2;
}

static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
{
	vcpu->arch.vsesr_el2 = vsesr;
}

static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
	return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
}

static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
{
	return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
}

static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
{
	return !!(*vcpu_cpsr(vcpu) & PSR_MODE32_BIT);
}

static __always_inline bool kvm_condition_valid(const struct kvm_vcpu *vcpu)
{
	if (vcpu_mode_is_32bit(vcpu))
		return kvm_condition_valid32(vcpu);

	return true;
}

static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
{
	*vcpu_cpsr(vcpu) |= PSR_AA32_T_BIT;
}

/*
 * vcpu_get_reg and vcpu_set_reg should always be passed a register number
 * coming from a read of ESR_EL2. Otherwise, it may give the wrong result on
 * AArch32 with banked registers.
 */
static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
					 u8 reg_num)
{
	return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
}

static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
				unsigned long val)
{
	if (reg_num != 31)
		vcpu_gp_regs(vcpu)->regs[reg_num] = val;
}

static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
{
	if (vcpu_mode_is_32bit(vcpu))
		return vcpu_read_spsr32(vcpu);

	if (vcpu->arch.sysregs_loaded_on_cpu)
		return read_sysreg_el1(SYS_SPSR);
	else
		return __vcpu_sys_reg(vcpu, SPSR_EL1);
}

static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
{
	if (vcpu_mode_is_32bit(vcpu)) {
		vcpu_write_spsr32(vcpu, v);
		return;
	}

	if (vcpu->arch.sysregs_loaded_on_cpu)
		write_sysreg_el1(v, SYS_SPSR);
	else
		__vcpu_sys_reg(vcpu, SPSR_EL1) = v;
}

/*
 * The layout of SPSR for an AArch32 state is different when observed from an
 * AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32
 * view given an AArch64 view.
 *
 * In ARM DDI 0487E.a see:
 *
 * - The AArch64 view (SPSR_EL2) in section C5.2.18, page C5-426
 * - The AArch32 view (SPSR_abt) in section G8.2.126, page G8-6256
 * - The AArch32 view (SPSR_und) in section G8.2.132, page G8-6280
 *
 * Which show the following differences:
 *
 * | Bit | AA64 | AA32 | Notes                       |
 * +-----+------+------+-----------------------------|
 * | 24  | DIT  | J    | J is RES0 in ARMv8          |
 * | 21  | SS   | DIT  | SS doesn't exist in AArch32 |
 *
 * ... and all other bits are (currently) common.
 */
static inline unsigned long host_spsr_to_spsr32(unsigned long spsr)
{
	const unsigned long overlap = BIT(24) | BIT(21);
	unsigned long dit = !!(spsr & PSR_AA32_DIT_BIT);

	spsr &= ~overlap;

	spsr |= dit << 21;

	return spsr;
}

static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
{
	u32 mode;

	if (vcpu_mode_is_32bit(vcpu)) {
		mode = *vcpu_cpsr(vcpu) & PSR_AA32_MODE_MASK;
		return mode > PSR_AA32_MODE_USR;
	}

	mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;

	return mode != PSR_MODE_EL0t;
}

static __always_inline u32 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu)
{
	return vcpu->arch.fault.esr_el2;
}

static __always_inline int kvm_vcpu_get_condition(const struct kvm_vcpu *vcpu)
{
	u32 esr = kvm_vcpu_get_esr(vcpu);

	if (esr & ESR_ELx_CV)
		return (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;

	return -1;
}

static __always_inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu)
{
	return vcpu->arch.fault.far_el2;
}

static __always_inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu)
{
	return ((phys_addr_t)vcpu->arch.fault.hpfar_el2 & HPFAR_MASK) << 8;
}

static inline u64 kvm_vcpu_get_disr(const struct kvm_vcpu *vcpu)
{
	return vcpu->arch.fault.disr_el1;
}

static inline u32 kvm_vcpu_hvc_get_imm(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_xVC_IMM_MASK;
}

static __always_inline bool kvm_vcpu_dabt_isvalid(const struct kvm_vcpu *vcpu)
{
	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_ISV);
}

static inline unsigned long kvm_vcpu_dabt_iss_nisv_sanitized(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_get_esr(vcpu) & (ESR_ELx_CM | ESR_ELx_WNR | ESR_ELx_FSC);
}

static inline bool kvm_vcpu_dabt_issext(const struct kvm_vcpu *vcpu)
{
	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SSE);
}

static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu)
{
	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SF);
}

static __always_inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
{
	return (kvm_vcpu_get_esr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
}

static __always_inline bool kvm_vcpu_abt_iss1tw(const struct kvm_vcpu *vcpu)
{
	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_S1PTW);
}

/* Always check for S1PTW *before* using this. */
static __always_inline bool kvm_vcpu_dabt_iswrite(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_WNR;
}

static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
{
	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_CM);
}

static __always_inline unsigned int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
{
	return 1 << ((kvm_vcpu_get_esr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT);
}

/* This one is not specific to Data Abort */
static __always_inline bool kvm_vcpu_trap_il_is32bit(const struct kvm_vcpu *vcpu)
{
	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_IL);
}

static __always_inline u8 kvm_vcpu_trap_get_class(const struct kvm_vcpu *vcpu)
{
	return ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
}

static inline bool kvm_vcpu_trap_is_iabt(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_IABT_LOW;
}

static inline bool kvm_vcpu_trap_is_exec_fault(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_trap_is_iabt(vcpu) && !kvm_vcpu_abt_iss1tw(vcpu);
}

static __always_inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC;
}

static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_TYPE;
}

static __always_inline u8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu)
{
	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL;
}

static __always_inline bool kvm_vcpu_abt_issea(const struct kvm_vcpu *vcpu)
{
	switch (kvm_vcpu_trap_get_fault(vcpu)) {
	case FSC_SEA:
	case FSC_SEA_TTW0:
	case FSC_SEA_TTW1:
	case FSC_SEA_TTW2:
	case FSC_SEA_TTW3:
	case FSC_SECC:
	case FSC_SECC_TTW0:
	case FSC_SECC_TTW1:
	case FSC_SECC_TTW2:
	case FSC_SECC_TTW3:
		return true;
	default:
		return false;
	}
}

static __always_inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
{
	u32 esr = kvm_vcpu_get_esr(vcpu);
	return ESR_ELx_SYS64_ISS_RT(esr);
}

static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
{
	if (kvm_vcpu_abt_iss1tw(vcpu)) {
		/*
		 * Only a permission fault on a S1PTW should be
		 * considered as a write. Otherwise, page tables baked
		 * in a read-only memslot will result in an exception
		 * being delivered in the guest.
		 *
		 * The drawback is that we end-up faulting twice if the
		 * guest is using any of HW AF/DB: a translation fault
		 * to map the page containing the PT (read only at
		 * first), then a permission fault to allow the flags
		 * to be set.
		 */
		switch (kvm_vcpu_trap_get_fault_type(vcpu)) {
		case ESR_ELx_FSC_PERM:
			return true;
		default:
			return false;
		}
	}

	if (kvm_vcpu_trap_is_iabt(vcpu))
		return false;

	return kvm_vcpu_dabt_iswrite(vcpu);
}

static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
{
	return vcpu_read_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
}

static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
{
	if (vcpu_mode_is_32bit(vcpu)) {
		*vcpu_cpsr(vcpu) |= PSR_AA32_E_BIT;
	} else {
		u64 sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
		sctlr |= (1 << 25);
		vcpu_write_sys_reg(vcpu, sctlr, SCTLR_EL1);
	}
}

static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
{
	if (vcpu_mode_is_32bit(vcpu))
		return !!(*vcpu_cpsr(vcpu) & PSR_AA32_E_BIT);

	return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & (1 << 25));
}

static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
						    unsigned long data,
						    unsigned int len)
{
	if (kvm_vcpu_is_be(vcpu)) {
		switch (len) {
		case 1:
			return data & 0xff;
		case 2:
			return be16_to_cpu(data & 0xffff);
		case 4:
			return be32_to_cpu(data & 0xffffffff);
		default:
			return be64_to_cpu(data);
		}
	} else {
		switch (len) {
		case 1:
			return data & 0xff;
		case 2:
			return le16_to_cpu(data & 0xffff);
		case 4:
			return le32_to_cpu(data & 0xffffffff);
		default:
			return le64_to_cpu(data);
		}
	}

	return data;		/* Leave LE untouched */
}

static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
						    unsigned long data,
						    unsigned int len)
{
	if (kvm_vcpu_is_be(vcpu)) {
		switch (len) {
		case 1:
			return data & 0xff;
		case 2:
			return cpu_to_be16(data & 0xffff);
		case 4:
			return cpu_to_be32(data & 0xffffffff);
		default:
			return cpu_to_be64(data);
		}
	} else {
		switch (len) {
		case 1:
			return data & 0xff;
		case 2:
			return cpu_to_le16(data & 0xffff);
		case 4:
			return cpu_to_le32(data & 0xffffffff);
		default:
			return cpu_to_le64(data);
		}
	}

	return data;		/* Leave LE untouched */
}

static __always_inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_instr)
{
	if (vcpu_mode_is_32bit(vcpu)) {
		kvm_skip_instr32(vcpu, is_wide_instr);
	} else {
		*vcpu_pc(vcpu) += 4;
		*vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;
	}

	/* advance the singlestep state machine */
	*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
}

/*
 * Skip an instruction which has been emulated at hyp while most guest sysregs
 * are live.
 */
static __always_inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)
{
	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
	vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);

	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));

	write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);
	write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
}

static inline bool vcpu_has_feature(struct kvm_vcpu *vcpu, int feature)
{
	return test_bit(feature, vcpu->arch.features);
}

#endif /* __ARM64_KVM_EMULATE_H__ */