From 7b6b46311a8562fb3a9e035ed6ffab6d49c28886 Mon Sep 17 00:00:00 2001 From: Jintack Lim Date: Fri, 3 Feb 2017 10:20:08 -0500 Subject: KVM: arm/arm64: Emulate the EL1 phys timer registers Emulate read and write operations to CNTP_TVAL, CNTP_CVAL and CNTP_CTL. Now VMs are able to use the EL1 physical timer. Signed-off-by: Jintack Lim Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1cd3464ff88d..0e26f8c2b56f 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -824,7 +824,14 @@ static bool access_cntp_tval(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - kvm_inject_undefined(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + u64 now = kvm_phys_timer_read(); + + if (p->is_write) + ptimer->cnt_cval = p->regval + now; + else + p->regval = ptimer->cnt_cval - now; + return true; } @@ -832,7 +839,25 @@ static bool access_cntp_ctl(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - kvm_inject_undefined(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (p->is_write) { + /* ISTATUS bit is read-only */ + ptimer->cnt_ctl = p->regval & ~ARCH_TIMER_CTRL_IT_STAT; + } else { + u64 now = kvm_phys_timer_read(); + + p->regval = ptimer->cnt_ctl; + /* + * 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 (ptimer->cnt_cval <= now) + p->regval |= ARCH_TIMER_CTRL_IT_STAT; + } + return true; } @@ -840,7 +865,13 @@ static bool access_cntp_cval(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - kvm_inject_undefined(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + + if (p->is_write) + ptimer->cnt_cval = p->regval; + else + p->regval = ptimer->cnt_cval; + return true; } -- cgit v1.2.3-59-g8ed1b