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Commit b9fb1739 authored by Jérémy Fanguède's avatar Jérémy Fanguède Committed by Christoffer Dall
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KVM: arm: Enable emulation of the physical timer



Set the handlers to emulate read and write operations for CNTP_CTL,
CNTP_CVAL and CNTP_TVAL registers in such a way that VMs can use the
physical timer.

Signed-off-by: default avatarJérémy Fanguède <j.fanguede@virtualopensystems.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent eac137b4
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+61 −0
Original line number Diff line number Diff line
@@ -270,6 +270,60 @@ static bool access_gic_sre(struct kvm_vcpu *vcpu,
	return true;
}

static bool access_cntp_tval(struct kvm_vcpu *vcpu,
			     const struct coproc_params *p,
			     const struct coproc_reg *r)
{
	u64 now = kvm_phys_timer_read();
	u64 val;

	if (p->is_write) {
		val = *vcpu_reg(vcpu, p->Rt1);
		kvm_arm_timer_set_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL, val + now);
	} else {
		val = kvm_arm_timer_get_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL);
		*vcpu_reg(vcpu, p->Rt1) = val - now;
	}

	return true;
}

static bool access_cntp_ctl(struct kvm_vcpu *vcpu,
			    const struct coproc_params *p,
			    const struct coproc_reg *r)
{
	u32 val;

	if (p->is_write) {
		val = *vcpu_reg(vcpu, p->Rt1);
		kvm_arm_timer_set_reg(vcpu, KVM_REG_ARM_PTIMER_CTL, val);
	} else {
		val = kvm_arm_timer_get_reg(vcpu, KVM_REG_ARM_PTIMER_CTL);
		*vcpu_reg(vcpu, p->Rt1) = val;
	}

	return true;
}

static bool access_cntp_cval(struct kvm_vcpu *vcpu,
			     const struct coproc_params *p,
			     const struct coproc_reg *r)
{
	u64 val;

	if (p->is_write) {
		val = (u64)*vcpu_reg(vcpu, p->Rt2) << 32;
		val |= *vcpu_reg(vcpu, p->Rt1);
		kvm_arm_timer_set_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL, val);
	} else {
		val = kvm_arm_timer_get_reg(vcpu, KVM_REG_ARM_PTIMER_CVAL);
		*vcpu_reg(vcpu, p->Rt1) = val;
		*vcpu_reg(vcpu, p->Rt2) = val >> 32;
	}

	return true;
}

/*
 * We could trap ID_DFR0 and tell the guest we don't support performance
 * monitoring.  Unfortunately the patch to make the kernel check ID_DFR0 was
@@ -423,10 +477,17 @@ static const struct coproc_reg cp15_regs[] = {
	{ CRn(13), CRm( 0), Op1( 0), Op2( 4), is32,
			NULL, reset_unknown, c13_TID_PRIV },

	/* CNTP */
	{ CRm64(14), Op1( 2), is64, access_cntp_cval},

	/* CNTKCTL: swapped by interrupt.S. */
	{ CRn(14), CRm( 1), Op1( 0), Op2( 0), is32,
			NULL, reset_val, c14_CNTKCTL, 0x00000000 },

	/* CNTP */
	{ CRn(14), CRm( 2), Op1( 0), Op2( 0), is32, access_cntp_tval },
	{ CRn(14), CRm( 2), Op1( 0), Op2( 1), is32, access_cntp_ctl },

	/* The Configuration Base Address Register. */
	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
};