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: Jérémy Fanguède <j.fangu...@virtualopensystems.com>
---

This patch is the equivalent of this one: [1], but for arm 32bits
instead of ARMv8 aarch32.

[1] https://patchwork.kernel.org/patch/10207019/

---
 arch/arm/kvm/coproc.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 6d1d2e2..3a02e76 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -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},
 };
-- 
2.7.4

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