arm64: KVM: fault injection into a guest

/*

 * Fault injection for 64bit guests.

 *

 * Copyright (C) 2012,2013 - ARM Ltd

 * Author: Marc Zyngier <marc.zyngier@arm.com>

 *

 * Based on arch/arm/kvm/emulate.c

 * Copyright (C) 2012 - Virtual Open Systems and Columbia University

 * Author: Christoffer Dall <c.dall@virtualopensystems.com>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <linux/kvm_host.h>

#include <asm/kvm_emulate.h>

#include <asm/esr.h>

#define PSTATE_FAULT_BITS_64 	(PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \

				 PSR_I_BIT | PSR_D_BIT)

#define EL1_EXCEPT_SYNC_OFFSET	0x200

static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)

{

	unsigned long cpsr = *vcpu_cpsr(vcpu);

	bool is_aarch32;

	u32 esr = 0;

	is_aarch32 = vcpu_mode_is_32bit(vcpu);

	*vcpu_spsr(vcpu) = cpsr;

	*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);

	*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;

	*vcpu_pc(vcpu) = vcpu_sys_reg(vcpu, VBAR_EL1) + EL1_EXCEPT_SYNC_OFFSET;

	vcpu_sys_reg(vcpu, FAR_EL1) = addr;

	/*

	 * Build an {i,d}abort, depending on the level and the

	 * instruction set. Report an external synchronous abort.

	 */

	if (kvm_vcpu_trap_il_is32bit(vcpu))

		esr |= ESR_EL1_IL;

	/*

	 * Here, the guest runs in AArch64 mode when in EL1. If we get

	 * an AArch32 fault, it means we managed to trap an EL0 fault.

	 */

	if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)

		esr |= (ESR_EL1_EC_IABT_EL0 << ESR_EL1_EC_SHIFT);

	else

		esr |= (ESR_EL1_EC_IABT_EL1 << ESR_EL1_EC_SHIFT);

	if (!is_iabt)

		esr |= ESR_EL1_EC_DABT_EL0;

	vcpu_sys_reg(vcpu, ESR_EL1) = esr | ESR_EL2_EC_xABT_xFSR_EXTABT;

}

static void inject_undef64(struct kvm_vcpu *vcpu)

{

	unsigned long cpsr = *vcpu_cpsr(vcpu);

	u32 esr = (ESR_EL1_EC_UNKNOWN << ESR_EL1_EC_SHIFT);

	*vcpu_spsr(vcpu) = cpsr;

	*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);

	*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;

	*vcpu_pc(vcpu) = vcpu_sys_reg(vcpu, VBAR_EL1) + EL1_EXCEPT_SYNC_OFFSET;

	/*

	 * Build an unknown exception, depending on the instruction

	 * set.

	 */

	if (kvm_vcpu_trap_il_is32bit(vcpu))

		esr |= ESR_EL1_IL;

	vcpu_sys_reg(vcpu, ESR_EL1) = esr;

}

/**

 * kvm_inject_dabt - inject a data abort into the guest

 * @vcpu: The VCPU to receive the undefined exception

 * @addr: The address to report in the DFAR

 *

 * It is assumed that this code is called from the VCPU thread and that the

 * VCPU therefore is not currently executing guest code.

 */

void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)

{

	inject_abt64(vcpu, false, addr);

}

/**

 * kvm_inject_pabt - inject a prefetch abort into the guest

 * @vcpu: The VCPU to receive the undefined exception

 * @addr: The address to report in the DFAR

 *

 * It is assumed that this code is called from the VCPU thread and that the

 * VCPU therefore is not currently executing guest code.

 */

void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)

{

	inject_abt64(vcpu, true, addr);

}

/**

 * kvm_inject_undefined - inject an undefined instruction into the guest

 *

 * It is assumed that this code is called from the VCPU thread and that the

 * VCPU therefore is not currently executing guest code.

 */

void kvm_inject_undefined(struct kvm_vcpu *vcpu)

{

	inject_undef64(vcpu);

}