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Commit 003300de authored by Marc Zyngier's avatar Marc Zyngier
Browse files

arm64: KVM: Plug the arch timer 



Add support for the in-kernel timer emulation.

Reviewed-by: default avatarChristopher Covington <cov@codeaurora.org>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent f61701e0

arch/arm64/kvm/hyp.S

+56 −0
Original line number Diff line number Diff line
@@ -390,6 +390,60 @@ __kvm_hyp_code_start: 
2:

.endm



.macro save_timer_state

	// x0: vcpu pointer

	ldr	x2, [x0, #VCPU_KVM]

	kern_hyp_va x2

	ldr	w3, [x2, #KVM_TIMER_ENABLED]

	cbz	w3, 1f



	mrs	x3, cntv_ctl_el0

	and	x3, x3, #3

	str	w3, [x0, #VCPU_TIMER_CNTV_CTL]

	bic	x3, x3, #1		// Clear Enable

	msr	cntv_ctl_el0, x3



	isb



	mrs	x3, cntv_cval_el0

	str	x3, [x0, #VCPU_TIMER_CNTV_CVAL]



1:

	// Allow physical timer/counter access for the host

	mrs	x2, cnthctl_el2

	orr	x2, x2, #3

	msr	cnthctl_el2, x2



	// Clear cntvoff for the host

	msr	cntvoff_el2, xzr

.endm



.macro restore_timer_state

	// x0: vcpu pointer

	// Disallow physical timer access for the guest

	// Physical counter access is allowed

	mrs	x2, cnthctl_el2

	orr	x2, x2, #1

	bic	x2, x2, #2

	msr	cnthctl_el2, x2



	ldr	x2, [x0, #VCPU_KVM]

	kern_hyp_va x2

	ldr	w3, [x2, #KVM_TIMER_ENABLED]

	cbz	w3, 1f



	ldr	x3, [x2, #KVM_TIMER_CNTVOFF]

	msr	cntvoff_el2, x3

	ldr	x2, [x0, #VCPU_TIMER_CNTV_CVAL]

	msr	cntv_cval_el0, x2

	isb



	ldr	w2, [x0, #VCPU_TIMER_CNTV_CTL]

	and	x2, x2, #3

	msr	cntv_ctl_el0, x2

1:

.endm



__save_sysregs:

	save_sysregs

	ret
@@ -433,6 +487,7 @@ ENTRY(__kvm_vcpu_run) 
	activate_vm



	restore_vgic_state

	restore_timer_state



	// Guest context

	add	x2, x0, #VCPU_CONTEXT
@@ -455,6 +510,7 @@ __kvm_vcpu_return: 
	bl __save_fpsimd

	bl __save_sysregs



	save_timer_state

	save_vgic_state



	deactivate_traps

arch/arm64/kvm/reset.c

+12 −0
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ 
#include <linux/kvm_host.h>

#include <linux/kvm.h>



#include <kvm/arm_arch_timer.h>



#include <asm/cputype.h>

#include <asm/ptrace.h>

#include <asm/kvm_arm.h>
@@ -36,6 +38,11 @@ static const struct kvm_regs default_regs_reset = { 
			PSR_F_BIT | PSR_D_BIT),

};



static const struct kvm_irq_level default_vtimer_irq = {

	.irq	= 27,

	.level	= 1,

};



int kvm_arch_dev_ioctl_check_extension(long ext)

{

	int r;
@@ -58,11 +65,13 @@ int kvm_arch_dev_ioctl_check_extension(long ext) 
 */

int kvm_reset_vcpu(struct kvm_vcpu *vcpu)

{

	const struct kvm_irq_level *cpu_vtimer_irq;

	const struct kvm_regs *cpu_reset;



	switch (vcpu->arch.target) {

	default:

		cpu_reset = &default_regs_reset;

		cpu_vtimer_irq = &default_vtimer_irq;

		break;

	}
@@ -72,5 +81,8 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) 
	/* Reset system registers */

	kvm_reset_sys_regs(vcpu);



	/* Reset timer */

	kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);



	return 0;

}