arch/arm64/kvm/debug.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Debug and Guest Debug support
  *
  * Copyright (C) 2015 - Linaro Ltd
  * Author: Alex Bennée <alex.bennee@linaro.org>
  */

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

 #include <asm/debug-monitors.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_emulate.h>

 #include "trace.h"

 /* These are the bits of MDSCR_EL1 we may manipulate */
 #define MDSCR_EL1_DEBUG_MASK	(DBG_MDSCR_SS | \
 				DBG_MDSCR_KDE | \
 				DBG_MDSCR_MDE)

 static DEFINE_PER_CPU(u64, mdcr_el2);

 /**
  * save/restore_guest_debug_regs
  *
  * For some debug operations we need to tweak some guest registers. As
  * a result we need to save the state of those registers before we
  * make those modifications.
  *
  * Guest access to MDSCR_EL1 is trapped by the hypervisor and handled
  * after we have restored the preserved value to the main context.
  */
 static void save_guest_debug_regs(struct kvm_vcpu *vcpu)
 {
 	u64 val = vcpu_read_sys_reg(vcpu, MDSCR_EL1);

 	vcpu->arch.guest_debug_preserved.mdscr_el1 = val;

 	trace_kvm_arm_set_dreg32("Saved MDSCR_EL1",
 				vcpu->arch.guest_debug_preserved.mdscr_el1);
 }

 static void restore_guest_debug_regs(struct kvm_vcpu *vcpu)
 {
 	u64 val = vcpu->arch.guest_debug_preserved.mdscr_el1;

 	vcpu_write_sys_reg(vcpu, val, MDSCR_EL1);

 	trace_kvm_arm_set_dreg32("Restored MDSCR_EL1",
 				vcpu_read_sys_reg(vcpu, MDSCR_EL1));
 }

 /**
  * kvm_arm_init_debug - grab what we need for debug
  *
  * Currently the sole task of this function is to retrieve the initial
  * value of mdcr_el2 so we can preserve MDCR_EL2.HPMN which has
  * presumably been set-up by some knowledgeable bootcode.
  *
  * It is called once per-cpu during CPU hyp initialisation.
  */

 void kvm_arm_init_debug(void)
 {
 	__this_cpu_write(mdcr_el2, kvm_call_hyp_ret(__kvm_get_mdcr_el2));
 }

 /**
  * kvm_arm_setup_mdcr_el2 - configure vcpu mdcr_el2 value
  *
  * @vcpu:	the vcpu pointer
  *
  * This ensures we will trap access to:
  *  - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
  *  - Debug ROM Address (MDCR_EL2_TDRA)
  *  - OS related registers (MDCR_EL2_TDOSA)
  *  - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
  *  - Self-hosted Trace Filter controls (MDCR_EL2_TTRF)
  */
 static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu)
 {
 	/*
 	 * This also clears MDCR_EL2_E2PB_MASK to disable guest access
 	 * to the profiling buffer.
 	 */
 	vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
 	vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
 				MDCR_EL2_TPMS |
 				MDCR_EL2_TTRF |
 				MDCR_EL2_TPMCR |
 				MDCR_EL2_TDRA |
 				MDCR_EL2_TDOSA);

 	/* Is the VM being debugged by userspace? */
 	if (vcpu->guest_debug)
 		/* Route all software debug exceptions to EL2 */
 		vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE;

 	/*
 	 * Trap debug register access when one of the following is true:
 	 *  - Userspace is using the hardware to debug the guest
 	 *  (KVM_GUESTDBG_USE_HW is set).
 	 *  - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear).
 	 */
 	if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) ||
 	    !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
 		vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;

 	trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);
 }

 /**
  * kvm_arm_vcpu_init_debug - setup vcpu debug traps
  *
  * @vcpu:	the vcpu pointer
  *
  * Set vcpu initial mdcr_el2 value.
  */
 void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu)
 {
 	preempt_disable();
 	kvm_arm_setup_mdcr_el2(vcpu);
 	preempt_enable();
 }

 /**
  * kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state
  */

 void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.debug_ptr = &vcpu->arch.vcpu_debug_state;
 }

 /**
  * kvm_arm_setup_debug - set up debug related stuff
  *
  * @vcpu:	the vcpu pointer
  *
  * This is called before each entry into the hypervisor to setup any
  * debug related registers. Currently this just ensures we will trap
  * access to:
  *  - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
  *  - Debug ROM Address (MDCR_EL2_TDRA)
  *  - OS related registers (MDCR_EL2_TDOSA)
  *  - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
  *  - Self-hosted Trace (MDCR_EL2_TTRF/MDCR_EL2_E2TB)
  *
  * Additionally, KVM only traps guest accesses to the debug registers if
  * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
  * flag on vcpu->arch.flags).  Since the guest must not interfere
  * with the hardware state when debugging the guest, we must ensure that
  * trapping is enabled whenever we are debugging the guest using the
  * debug registers.
  */

 void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
 {
 	unsigned long mdscr, orig_mdcr_el2 = vcpu->arch.mdcr_el2;

 	trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);

 	kvm_arm_setup_mdcr_el2(vcpu);

 	/* Is Guest debugging in effect? */
 	if (vcpu->guest_debug) {
 		/* Save guest debug state */
 		save_guest_debug_regs(vcpu);

 		/*
 		 * Single Step (ARM ARM D2.12.3 The software step state
 		 * machine)
 		 *
 		 * If we are doing Single Step we need to manipulate
 		 * the guest's MDSCR_EL1.SS and PSTATE.SS. Once the
 		 * step has occurred the hypervisor will trap the
 		 * debug exception and we return to userspace.
 		 *
 		 * If the guest attempts to single step its userspace
 		 * we would have to deal with a trapped exception
 		 * while in the guest kernel. Because this would be
 		 * hard to unwind we suppress the guest's ability to
 		 * do so by masking MDSCR_EL.SS.
 		 *
 		 * This confuses guest debuggers which use
 		 * single-step behind the scenes but everything
 		 * returns to normal once the host is no longer
 		 * debugging the system.
 		 */
 		if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
 			*vcpu_cpsr(vcpu) |=  DBG_SPSR_SS;
 			mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1);
 			mdscr |= DBG_MDSCR_SS;
 			vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);
 		} else {
 			mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1);
 			mdscr &= ~DBG_MDSCR_SS;
 			vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);
 		}

 		trace_kvm_arm_set_dreg32("SPSR_EL2", *vcpu_cpsr(vcpu));

 		/*
 		 * HW Breakpoints and watchpoints
 		 *
 		 * We simply switch the debug_ptr to point to our new
 		 * external_debug_state which has been populated by the
 		 * debug ioctl. The existing KVM_ARM64_DEBUG_DIRTY
 		 * mechanism ensures the registers are updated on the
 		 * world switch.
 		 */
 		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
 			/* Enable breakpoints/watchpoints */
 			mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1);
 			mdscr |= DBG_MDSCR_MDE;
 			vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);

 			vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state;
 			vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;

 			trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
 						&vcpu->arch.debug_ptr->dbg_bcr[0],
 						&vcpu->arch.debug_ptr->dbg_bvr[0]);

 			trace_kvm_arm_set_regset("WAPTS", get_num_wrps(),
 						&vcpu->arch.debug_ptr->dbg_wcr[0],
 						&vcpu->arch.debug_ptr->dbg_wvr[0]);
 		}
 	}

 	BUG_ON(!vcpu->guest_debug &&
 		vcpu->arch.debug_ptr != &vcpu->arch.vcpu_debug_state);

 	/* If KDE or MDE are set, perform a full save/restore cycle. */
 	if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE))
 		vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;

 	/* Write mdcr_el2 changes since vcpu_load on VHE systems */
 	if (has_vhe() && orig_mdcr_el2 != vcpu->arch.mdcr_el2)
 		write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);

 	trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1));
 }

 void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)
 {
 	trace_kvm_arm_clear_debug(vcpu->guest_debug);

 	if (vcpu->guest_debug) {
 		restore_guest_debug_regs(vcpu);

 		/*
 		 * If we were using HW debug we need to restore the
 		 * debug_ptr to the guest debug state.
 		 */
 		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
 			kvm_arm_reset_debug_ptr(vcpu);

 			trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
 						&vcpu->arch.debug_ptr->dbg_bcr[0],
 						&vcpu->arch.debug_ptr->dbg_bvr[0]);

 			trace_kvm_arm_set_regset("WAPTS", get_num_wrps(),
 						&vcpu->arch.debug_ptr->dbg_wcr[0],
 						&vcpu->arch.debug_ptr->dbg_wvr[0]);
 		}
 	}
 }

 void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu)
 {
 	u64 dfr0;

 	/* For VHE, there is nothing to do */
 	if (has_vhe())
 		return;

 	dfr0 = read_sysreg(id_aa64dfr0_el1);
 	/*
 	 * If SPE is present on this CPU and is available at current EL,
 	 * we may need to check if the host state needs to be saved.
 	 */
 	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMSVER_SHIFT) &&
 	    !(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(SYS_PMBIDR_EL1_P_SHIFT)))
 		vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_SPE;

 	/* Check if we have TRBE implemented and available at the host */
 	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRBE_SHIFT) &&
 	    !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_PROG))
 		vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_TRBE;
 }

 void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.flags &= ~(KVM_ARM64_DEBUG_STATE_SAVE_SPE |
 			      KVM_ARM64_DEBUG_STATE_SAVE_TRBE);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Debug and Guest Debug support
	*
	* Copyright (C) 2015 - Linaro Ltd
	* Author: Alex Bennée <alex.bennee@linaro.org>
	*/

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

	#include <asm/debug-monitors.h>
	#include <asm/kvm_asm.h>
	#include <asm/kvm_arm.h>
	#include <asm/kvm_emulate.h>

	#include "trace.h"

	/* These are the bits of MDSCR_EL1 we may manipulate */
	#define MDSCR_EL1_DEBUG_MASK (DBG_MDSCR_SS \| \
	DBG_MDSCR_KDE \| \
	DBG_MDSCR_MDE)

	static DEFINE_PER_CPU(u64, mdcr_el2);

	/**
	* save/restore_guest_debug_regs
	*
	* For some debug operations we need to tweak some guest registers. As
	* a result we need to save the state of those registers before we
	* make those modifications.
	*
	* Guest access to MDSCR_EL1 is trapped by the hypervisor and handled
	* after we have restored the preserved value to the main context.
	*/
	static void save_guest_debug_regs(struct kvm_vcpu *vcpu)
	{
	u64 val = vcpu_read_sys_reg(vcpu, MDSCR_EL1);

	vcpu->arch.guest_debug_preserved.mdscr_el1 = val;

	trace_kvm_arm_set_dreg32("Saved MDSCR_EL1",
	vcpu->arch.guest_debug_preserved.mdscr_el1);
	}

	static void restore_guest_debug_regs(struct kvm_vcpu *vcpu)
	{
	u64 val = vcpu->arch.guest_debug_preserved.mdscr_el1;

	vcpu_write_sys_reg(vcpu, val, MDSCR_EL1);

	trace_kvm_arm_set_dreg32("Restored MDSCR_EL1",
	vcpu_read_sys_reg(vcpu, MDSCR_EL1));
	}

	/**
	* kvm_arm_init_debug - grab what we need for debug
	*
	* Currently the sole task of this function is to retrieve the initial
	* value of mdcr_el2 so we can preserve MDCR_EL2.HPMN which has
	* presumably been set-up by some knowledgeable bootcode.
	*
	* It is called once per-cpu during CPU hyp initialisation.
	*/

	void kvm_arm_init_debug(void)
	{
	__this_cpu_write(mdcr_el2, kvm_call_hyp_ret(__kvm_get_mdcr_el2));
	}

	/**
	* kvm_arm_setup_mdcr_el2 - configure vcpu mdcr_el2 value
	*
	* @vcpu: the vcpu pointer
	*
	* This ensures we will trap access to:
	* - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
	* - Debug ROM Address (MDCR_EL2_TDRA)
	* - OS related registers (MDCR_EL2_TDOSA)
	* - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
	* - Self-hosted Trace Filter controls (MDCR_EL2_TTRF)
	*/
	static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu)
	{
	/*
	* This also clears MDCR_EL2_E2PB_MASK to disable guest access
	* to the profiling buffer.
	*/
	vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
	vcpu->arch.mdcr_el2 \|= (MDCR_EL2_TPM \|
	MDCR_EL2_TPMS \|
	MDCR_EL2_TTRF \|
	MDCR_EL2_TPMCR \|
	MDCR_EL2_TDRA \|
	MDCR_EL2_TDOSA);

	/* Is the VM being debugged by userspace? */
	if (vcpu->guest_debug)
	/* Route all software debug exceptions to EL2 */
	vcpu->arch.mdcr_el2 \|= MDCR_EL2_TDE;

	/*
	* Trap debug register access when one of the following is true:
	* - Userspace is using the hardware to debug the guest
	* (KVM_GUESTDBG_USE_HW is set).
	* - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear).
	*/
	if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) \|\|
	!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
	vcpu->arch.mdcr_el2 \|= MDCR_EL2_TDA;

	trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);
	}

	/**
	* kvm_arm_vcpu_init_debug - setup vcpu debug traps
	*
	* @vcpu: the vcpu pointer
	*
	* Set vcpu initial mdcr_el2 value.
	*/
	void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu)
	{
	preempt_disable();
	kvm_arm_setup_mdcr_el2(vcpu);
	preempt_enable();
	}

	/**
	* kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state
	*/

	void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
	{
	vcpu->arch.debug_ptr = &vcpu->arch.vcpu_debug_state;
	}

	/**
	* kvm_arm_setup_debug - set up debug related stuff
	*
	* @vcpu: the vcpu pointer
	*
	* This is called before each entry into the hypervisor to setup any
	* debug related registers. Currently this just ensures we will trap
	* access to:
	* - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
	* - Debug ROM Address (MDCR_EL2_TDRA)
	* - OS related registers (MDCR_EL2_TDOSA)
	* - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
	* - Self-hosted Trace (MDCR_EL2_TTRF/MDCR_EL2_E2TB)
	*
	* Additionally, KVM only traps guest accesses to the debug registers if
	* the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
	* flag on vcpu->arch.flags). Since the guest must not interfere
	* with the hardware state when debugging the guest, we must ensure that
	* trapping is enabled whenever we are debugging the guest using the
	* debug registers.
	*/

	void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
	{
	unsigned long mdscr, orig_mdcr_el2 = vcpu->arch.mdcr_el2;

	trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);

	kvm_arm_setup_mdcr_el2(vcpu);

	/* Is Guest debugging in effect? */
	if (vcpu->guest_debug) {
	/* Save guest debug state */
	save_guest_debug_regs(vcpu);

	/*
	* Single Step (ARM ARM D2.12.3 The software step state
	* machine)
	*
	* If we are doing Single Step we need to manipulate
	* the guest's MDSCR_EL1.SS and PSTATE.SS. Once the
	* step has occurred the hypervisor will trap the
	* debug exception and we return to userspace.
	*
	* If the guest attempts to single step its userspace
	* we would have to deal with a trapped exception
	* while in the guest kernel. Because this would be
	* hard to unwind we suppress the guest's ability to
	* do so by masking MDSCR_EL.SS.
	*
	* This confuses guest debuggers which use
	* single-step behind the scenes but everything
	* returns to normal once the host is no longer
	* debugging the system.
	*/
	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
	*vcpu_cpsr(vcpu) \|= DBG_SPSR_SS;
	mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1);
	mdscr \|= DBG_MDSCR_SS;
	vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);
	} else {
	mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1);
	mdscr &= ~DBG_MDSCR_SS;
	vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);
	}

	trace_kvm_arm_set_dreg32("SPSR_EL2", *vcpu_cpsr(vcpu));

	/*
	* HW Breakpoints and watchpoints
	*
	* We simply switch the debug_ptr to point to our new
	* external_debug_state which has been populated by the
	* debug ioctl. The existing KVM_ARM64_DEBUG_DIRTY
	* mechanism ensures the registers are updated on the
	* world switch.
	*/
	if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
	/* Enable breakpoints/watchpoints */
	mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1);
	mdscr \|= DBG_MDSCR_MDE;
	vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);

	vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state;
	vcpu->arch.flags \|= KVM_ARM64_DEBUG_DIRTY;

	trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
	&vcpu->arch.debug_ptr->dbg_bcr[0],
	&vcpu->arch.debug_ptr->dbg_bvr[0]);

	trace_kvm_arm_set_regset("WAPTS", get_num_wrps(),
	&vcpu->arch.debug_ptr->dbg_wcr[0],
	&vcpu->arch.debug_ptr->dbg_wvr[0]);
	}
	}

	BUG_ON(!vcpu->guest_debug &&
	vcpu->arch.debug_ptr != &vcpu->arch.vcpu_debug_state);

	/* If KDE or MDE are set, perform a full save/restore cycle. */
	if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE \| DBG_MDSCR_MDE))
	vcpu->arch.flags \|= KVM_ARM64_DEBUG_DIRTY;

	/* Write mdcr_el2 changes since vcpu_load on VHE systems */
	if (has_vhe() && orig_mdcr_el2 != vcpu->arch.mdcr_el2)
	write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);

	trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1));
	}

	void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)
	{
	trace_kvm_arm_clear_debug(vcpu->guest_debug);

	if (vcpu->guest_debug) {
	restore_guest_debug_regs(vcpu);

	/*
	* If we were using HW debug we need to restore the
	* debug_ptr to the guest debug state.
	*/
	if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
	kvm_arm_reset_debug_ptr(vcpu);

	trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
	&vcpu->arch.debug_ptr->dbg_bcr[0],
	&vcpu->arch.debug_ptr->dbg_bvr[0]);

	trace_kvm_arm_set_regset("WAPTS", get_num_wrps(),
	&vcpu->arch.debug_ptr->dbg_wcr[0],
	&vcpu->arch.debug_ptr->dbg_wvr[0]);
	}
	}
	}

	void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu)
	{
	u64 dfr0;

	/* For VHE, there is nothing to do */
	if (has_vhe())
	return;

	dfr0 = read_sysreg(id_aa64dfr0_el1);
	/*
	* If SPE is present on this CPU and is available at current EL,
	* we may need to check if the host state needs to be saved.
	*/
	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMSVER_SHIFT) &&
	!(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(SYS_PMBIDR_EL1_P_SHIFT)))
	vcpu->arch.flags \|= KVM_ARM64_DEBUG_STATE_SAVE_SPE;

	/* Check if we have TRBE implemented and available at the host */
	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRBE_SHIFT) &&
	!(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_PROG))
	vcpu->arch.flags \|= KVM_ARM64_DEBUG_STATE_SAVE_TRBE;
	}

	void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu)
	{
	vcpu->arch.flags &= ~(KVM_ARM64_DEBUG_STATE_SAVE_SPE \|
	KVM_ARM64_DEBUG_STATE_SAVE_TRBE);
	}