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 ++++++++++++++++++++++++++++++++++--- include/kvm/arm_arch_timer.h | 2 ++ virt/kvm/arm/arch_timer.c | 2 +- 3 files changed, 37 insertions(+), 4 deletions(-) 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; } diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index f1d2fba0b9c6..fe797d6ef89d 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -72,6 +72,8 @@ bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx); void kvm_timer_schedule(struct kvm_vcpu *vcpu); void kvm_timer_unschedule(struct kvm_vcpu *vcpu); +u64 kvm_phys_timer_read(void); + void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu); void kvm_timer_init_vhe(void); diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 33257b560f74..35d7100e0815 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -40,7 +40,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) vcpu_vtimer(vcpu)->active_cleared_last = false; } -static u64 kvm_phys_timer_read(void) +u64 kvm_phys_timer_read(void) { return timecounter->cc->read(timecounter->cc); } -- cgit v1.2.3-59-g8ed1b