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Commit 5c5196da authored by Christoffer Dall's avatar Christoffer Dall Committed by Christoffer Dall
Browse files

KVM: arm/arm64: Support EL1 phys timer register access in set/get reg 



Add suport for the physical timer registers in kvm_arm_timer_set_reg and
kvm_arm_timer_get_reg so that these functions can be reused to interact
with the rest of the system.

Note that this paves part of the way for the physical timer state
save/restore, but we still need to add those registers to
KVM_GET_REG_LIST before we support migrating the physical timer state.

Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent b103cc3f

arch/arm/include/uapi/asm/kvm.h

+6 −0
Original line number Diff line number Diff line
@@ -151,6 +151,12 @@ struct kvm_arch_memory_slot { 
	(__ARM_CP15_REG(op1, 0, crm, 0) | KVM_REG_SIZE_U64)

#define ARM_CP15_REG64(...) __ARM_CP15_REG64(__VA_ARGS__)



/* PL1 Physical Timer Registers */

#define KVM_REG_ARM_PTIMER_CTL		ARM_CP15_REG32(0, 14, 2, 1)

#define KVM_REG_ARM_PTIMER_CNT		ARM_CP15_REG64(0, 14)

#define KVM_REG_ARM_PTIMER_CVAL		ARM_CP15_REG64(2, 14)



/* Virtual Timer Registers */

#define KVM_REG_ARM_TIMER_CTL		ARM_CP15_REG32(0, 14, 3, 1)

#define KVM_REG_ARM_TIMER_CNT		ARM_CP15_REG64(1, 14)

#define KVM_REG_ARM_TIMER_CVAL		ARM_CP15_REG64(3, 14)

arch/arm64/include/uapi/asm/kvm.h

+6 −0
Original line number Diff line number Diff line
@@ -195,6 +195,12 @@ struct kvm_arch_memory_slot { 


#define ARM64_SYS_REG(...) (__ARM64_SYS_REG(__VA_ARGS__) | KVM_REG_SIZE_U64)



/* Physical Timer EL0 Registers */

#define KVM_REG_ARM_PTIMER_CTL		ARM64_SYS_REG(3, 3, 14, 2, 1)

#define KVM_REG_ARM_PTIMER_CVAL		ARM64_SYS_REG(3, 3, 14, 2, 2)

#define KVM_REG_ARM_PTIMER_CNT		ARM64_SYS_REG(3, 3, 14, 0, 1)



/* EL0 Virtual Timer Registers */

#define KVM_REG_ARM_TIMER_CTL		ARM64_SYS_REG(3, 3, 14, 3, 1)

#define KVM_REG_ARM_TIMER_CNT		ARM64_SYS_REG(3, 3, 14, 3, 2)

#define KVM_REG_ARM_TIMER_CVAL		ARM64_SYS_REG(3, 3, 14, 0, 2)

virt/kvm/arm/arch_timer.c

+31 −2
Original line number Diff line number Diff line
@@ -628,10 +628,11 @@ static void kvm_timer_init_interrupt(void *info) 
int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)

{

	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);

	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);



	switch (regid) {

	case KVM_REG_ARM_TIMER_CTL:

		vtimer->cnt_ctl = value;

		vtimer->cnt_ctl = value & ~ARCH_TIMER_CTRL_IT_STAT;

		break;

	case KVM_REG_ARM_TIMER_CNT:

		update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value);
@@ -639,6 +640,13 @@ int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) 
	case KVM_REG_ARM_TIMER_CVAL:

		vtimer->cnt_cval = value;

		break;

	case KVM_REG_ARM_PTIMER_CTL:

		ptimer->cnt_ctl = value & ~ARCH_TIMER_CTRL_IT_STAT;

		break;

	case KVM_REG_ARM_PTIMER_CVAL:

		ptimer->cnt_cval = value;

		break;



	default:

		return -1;

	}
@@ -647,17 +655,38 @@ int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) 
	return 0;

}



static u64 read_timer_ctl(struct arch_timer_context *timer)

{

	/*

	 * Set ISTATUS bit if it's expired.

	 * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is

	 * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit

	 * regardless of ENABLE bit for our implementation convenience.

	 */

	if (!kvm_timer_compute_delta(timer))

		return timer->cnt_ctl | ARCH_TIMER_CTRL_IT_STAT;

	else

		return timer->cnt_ctl;

}



u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid)

{

	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);



	switch (regid) {

	case KVM_REG_ARM_TIMER_CTL:

		return vtimer->cnt_ctl;

		return read_timer_ctl(vtimer);

	case KVM_REG_ARM_TIMER_CNT:

		return kvm_phys_timer_read() - vtimer->cntvoff;

	case KVM_REG_ARM_TIMER_CVAL:

		return vtimer->cnt_cval;

	case KVM_REG_ARM_PTIMER_CTL:

		return read_timer_ctl(ptimer);

	case KVM_REG_ARM_PTIMER_CVAL:

		return ptimer->cnt_cval;

	case KVM_REG_ARM_PTIMER_CNT:

		return kvm_phys_timer_read();

	}

	return (u64)-1;

}