arch/arm64/kvm/hyp/include/hyp/debug-sr.h

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2015 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */

#ifndef __ARM64_KVM_HYP_DEBUG_SR_H__
#define __ARM64_KVM_HYP_DEBUG_SR_H__

#include <linux/compiler.h>
#include <linux/kvm_host.h>

#include <asm/debug-monitors.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>

#define read_debug(r,n)		read_sysreg(r##n##_el1)
#define write_debug(v,r,n)	write_sysreg(v, r##n##_el1)

#define save_debug(ptr,reg,nr)						\
	switch (nr) {							\
	case 15:	ptr[15] = read_debug(reg, 15);			\
			/* Fall through */				\
	case 14:	ptr[14] = read_debug(reg, 14);			\
			/* Fall through */				\
	case 13:	ptr[13] = read_debug(reg, 13);			\
			/* Fall through */				\
	case 12:	ptr[12] = read_debug(reg, 12);			\
			/* Fall through */				\
	case 11:	ptr[11] = read_debug(reg, 11);			\
			/* Fall through */				\
	case 10:	ptr[10] = read_debug(reg, 10);			\
			/* Fall through */				\
	case 9:		ptr[9] = read_debug(reg, 9);			\
			/* Fall through */				\
	case 8:		ptr[8] = read_debug(reg, 8);			\
			/* Fall through */				\
	case 7:		ptr[7] = read_debug(reg, 7);			\
			/* Fall through */				\
	case 6:		ptr[6] = read_debug(reg, 6);			\
			/* Fall through */				\
	case 5:		ptr[5] = read_debug(reg, 5);			\
			/* Fall through */				\
	case 4:		ptr[4] = read_debug(reg, 4);			\
			/* Fall through */				\
	case 3:		ptr[3] = read_debug(reg, 3);			\
			/* Fall through */				\
	case 2:		ptr[2] = read_debug(reg, 2);			\
			/* Fall through */				\
	case 1:		ptr[1] = read_debug(reg, 1);			\
			/* Fall through */				\
	default:	ptr[0] = read_debug(reg, 0);			\
	}

#define restore_debug(ptr,reg,nr)					\
	switch (nr) {							\
	case 15:	write_debug(ptr[15], reg, 15);			\
			/* Fall through */				\
	case 14:	write_debug(ptr[14], reg, 14);			\
			/* Fall through */				\
	case 13:	write_debug(ptr[13], reg, 13);			\
			/* Fall through */				\
	case 12:	write_debug(ptr[12], reg, 12);			\
			/* Fall through */				\
	case 11:	write_debug(ptr[11], reg, 11);			\
			/* Fall through */				\
	case 10:	write_debug(ptr[10], reg, 10);			\
			/* Fall through */				\
	case 9:		write_debug(ptr[9], reg, 9);			\
			/* Fall through */				\
	case 8:		write_debug(ptr[8], reg, 8);			\
			/* Fall through */				\
	case 7:		write_debug(ptr[7], reg, 7);			\
			/* Fall through */				\
	case 6:		write_debug(ptr[6], reg, 6);			\
			/* Fall through */				\
	case 5:		write_debug(ptr[5], reg, 5);			\
			/* Fall through */				\
	case 4:		write_debug(ptr[4], reg, 4);			\
			/* Fall through */				\
	case 3:		write_debug(ptr[3], reg, 3);			\
			/* Fall through */				\
	case 2:		write_debug(ptr[2], reg, 2);			\
			/* Fall through */				\
	case 1:		write_debug(ptr[1], reg, 1);			\
			/* Fall through */				\
	default:	write_debug(ptr[0], reg, 0);			\
	}

static void __debug_save_state(struct kvm_guest_debug_arch *dbg,
			       struct kvm_cpu_context *ctxt)
{
	u64 aa64dfr0;
	int brps, wrps;

	aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
	brps = (aa64dfr0 >> 12) & 0xf;
	wrps = (aa64dfr0 >> 20) & 0xf;

	save_debug(dbg->dbg_bcr, dbgbcr, brps);
	save_debug(dbg->dbg_bvr, dbgbvr, brps);
	save_debug(dbg->dbg_wcr, dbgwcr, wrps);
	save_debug(dbg->dbg_wvr, dbgwvr, wrps);

	ctxt_sys_reg(ctxt, MDCCINT_EL1) = read_sysreg(mdccint_el1);
}

static void __debug_restore_state(struct kvm_guest_debug_arch *dbg,
				  struct kvm_cpu_context *ctxt)
{
	u64 aa64dfr0;
	int brps, wrps;

	aa64dfr0 = read_sysreg(id_aa64dfr0_el1);

	brps = (aa64dfr0 >> 12) & 0xf;
	wrps = (aa64dfr0 >> 20) & 0xf;

	restore_debug(dbg->dbg_bcr, dbgbcr, brps);
	restore_debug(dbg->dbg_bvr, dbgbvr, brps);
	restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
	restore_debug(dbg->dbg_wvr, dbgwvr, wrps);

	write_sysreg(ctxt_sys_reg(ctxt, MDCCINT_EL1), mdccint_el1);
}

static inline void __debug_switch_to_guest_common(struct kvm_vcpu *vcpu)
{
	struct kvm_cpu_context *host_ctxt;
	struct kvm_cpu_context *guest_ctxt;
	struct kvm_guest_debug_arch *host_dbg;
	struct kvm_guest_debug_arch *guest_dbg;

	if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
		return;

	host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
	guest_ctxt = &vcpu->arch.ctxt;
	host_dbg = &vcpu->arch.host_debug_state.regs;
	guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);

	__debug_save_state(host_dbg, host_ctxt);
	__debug_restore_state(guest_dbg, guest_ctxt);
}

static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu)
{
	struct kvm_cpu_context *host_ctxt;
	struct kvm_cpu_context *guest_ctxt;
	struct kvm_guest_debug_arch *host_dbg;
	struct kvm_guest_debug_arch *guest_dbg;

	if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
		return;

	host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
	guest_ctxt = &vcpu->arch.ctxt;
	host_dbg = &vcpu->arch.host_debug_state.regs;
	guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);

	__debug_save_state(guest_dbg, guest_ctxt);
	__debug_restore_state(host_dbg, host_ctxt);

	vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
}

#endif /* __ARM64_KVM_HYP_DEBUG_SR_H__ */