Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1431af36 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

arm64: KVM: Implement timer save/restore 



Implement the timer save restore as a direct translation of
the assembly code version.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent f68d2b1b

arch/arm64/kvm/hyp/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,3 +4,4 @@ 


obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o

obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o

obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o

arch/arm64/kvm/hyp/hyp.h

+3 −0
Original line number Diff line number Diff line
@@ -35,5 +35,8 @@ void __vgic_v2_restore_state(struct kvm_vcpu *vcpu); 
void __vgic_v3_save_state(struct kvm_vcpu *vcpu);

void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);



void __timer_save_state(struct kvm_vcpu *vcpu);

void __timer_restore_state(struct kvm_vcpu *vcpu);



#endif /* __ARM64_KVM_HYP_H__ */

arch/arm64/kvm/hyp/timer-sr.c

0 → 100644
+71 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012-2015 - ARM Ltd

 * Author: Marc Zyngier <marc.zyngier@arm.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 <clocksource/arm_arch_timer.h>

#include <linux/compiler.h>

#include <linux/kvm_host.h>



#include <asm/kvm_mmu.h>



#include "hyp.h"



/* vcpu is already in the HYP VA space */

void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)

{

	struct kvm *kvm = kern_hyp_va(vcpu->kvm);

	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	u64 val;



	if (kvm->arch.timer.enabled) {

		timer->cntv_ctl = read_sysreg(cntv_ctl_el0);

		timer->cntv_cval = read_sysreg(cntv_cval_el0);

	}



	/* Disable the virtual timer */

	write_sysreg(0, cntv_ctl_el0);



	/* Allow physical timer/counter access for the host */

	val = read_sysreg(cnthctl_el2);

	val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;

	write_sysreg(val, cnthctl_el2);



	/* Clear cntvoff for the host */

	write_sysreg(0, cntvoff_el2);

}



void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)

{

	struct kvm *kvm = kern_hyp_va(vcpu->kvm);

	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;

	u64 val;



	/*

	 * Disallow physical timer access for the guest

	 * Physical counter access is allowed

	 */

	val = read_sysreg(cnthctl_el2);

	val &= ~CNTHCTL_EL1PCEN;

	val |= CNTHCTL_EL1PCTEN;

	write_sysreg(val, cnthctl_el2);



	if (kvm->arch.timer.enabled) {

		write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2);

		write_sysreg(timer->cntv_cval, cntv_cval_el0);

		isb();

		write_sysreg(timer->cntv_ctl, cntv_ctl_el0);

	}

}

include/clocksource/arm_arch_timer.h

+6 −0
Original line number Diff line number Diff line
@@ -23,6 +23,12 @@ 
#define ARCH_TIMER_CTRL_IT_MASK		(1 << 1)

#define ARCH_TIMER_CTRL_IT_STAT		(1 << 2)



#define CNTHCTL_EL1PCTEN		(1 << 0)

#define CNTHCTL_EL1PCEN			(1 << 1)

#define CNTHCTL_EVNTEN			(1 << 2)

#define CNTHCTL_EVNTDIR			(1 << 3)

#define CNTHCTL_EVNTI			(0xF << 4)



enum arch_timer_reg {

	ARCH_TIMER_REG_CTRL,

	ARCH_TIMER_REG_TVAL,