On Fri, Jan 27 2017 at 01:05:00 AM, Jintack Lim <jintack@xxxxxxxxxxxxxxx> wrote:
> 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 <jintack@xxxxxxxxxxxxxxx>
> ---
> arch/arm64/kvm/sys_regs.c | 32 +++++++++++++++++++++++++++++---
> include/kvm/arm_arch_timer.h | 2 ++
> virt/kvm/arm/arch_timer.c | 2 +-
> 3 files changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index fd9e747..adf009f 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 +839,20 @@ 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 */
> + if (ptimer->cnt_cval <= now)
> + p->regval |= ARCH_TIMER_CTRL_IT_STAT;
> + }
Shouldn't we take the ENABLE bit into account? The ARMv8 ARM version I
have at hand (version h) seems to indicate that we should, but we should
check with the latest and greatest...
> +
> return true;
> }
>
> @@ -840,7 +860,13 @@ 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 a364593..fec99f2 100644
> --- a/include/kvm/arm_arch_timer.h
> +++ b/include/kvm/arm_arch_timer.h
> @@ -74,6 +74,8 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu,
> 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 b366bb2..9eec063 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);
> }
Thanks,
M.
--
Jazz is not dead. It just smells funny.
