Messages in this thread | | | Date | Mon, 18 Mar 2024 16:58:08 +0530 | Subject | Re: [RFC PATCH 12/28] KVM: arm64: Support timers in realm RECs | From | Ganapatrao Kulkarni <> |
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On 27-01-2023 04:59 pm, Steven Price wrote: > The RMM keeps track of the timer while the realm REC is running, but on > exit to the normal world KVM is responsible for handling the timers. > > Signed-off-by: Steven Price <steven.price@arm.com> > --- > arch/arm64/kvm/arch_timer.c | 53 ++++++++++++++++++++++++++++++++---- > include/kvm/arm_arch_timer.h | 2 ++ > 2 files changed, 49 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c > index bb24a76b4224..d4af9ee58550 100644 > --- a/arch/arm64/kvm/arch_timer.c > +++ b/arch/arm64/kvm/arch_timer.c > @@ -130,6 +130,11 @@ static void timer_set_offset(struct arch_timer_context *ctxt, u64 offset) > { > struct kvm_vcpu *vcpu = ctxt->vcpu; > > + if (kvm_is_realm(vcpu->kvm)) { > + WARN_ON(offset); > + return; > + } > + > switch(arch_timer_ctx_index(ctxt)) { > case TIMER_VTIMER: > __vcpu_sys_reg(vcpu, CNTVOFF_EL2) = offset; > @@ -411,6 +416,21 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, > } > } > > +void kvm_realm_timers_update(struct kvm_vcpu *vcpu) > +{ > + struct arch_timer_cpu *arch_timer = &vcpu->arch.timer_cpu; > + int i; > + > + for (i = 0; i < NR_KVM_TIMERS; i++) {
Do we required to check for all timers, is realm/rmm uses hyp timers?
> + struct arch_timer_context *timer = &arch_timer->timers[i]; > + bool status = timer_get_ctl(timer) & ARCH_TIMER_CTRL_IT_STAT; > + bool level = kvm_timer_irq_can_fire(timer) && status; > + > + if (level != timer->irq.level) > + kvm_timer_update_irq(vcpu, level, timer); > + } > +} > + > /* Only called for a fully emulated timer */ > static void timer_emulate(struct arch_timer_context *ctx) > { > @@ -621,6 +641,11 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu) > if (unlikely(!timer->enabled)) > return; > > + kvm_timer_unblocking(vcpu); > + > + if (vcpu_is_rec(vcpu)) > + return; > +
For realm, timer->enabled is not set, load returns before this check.
> get_timer_map(vcpu, &map); > > if (static_branch_likely(&has_gic_active_state)) { > @@ -633,8 +658,6 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu) > > set_cntvoff(timer_get_offset(map.direct_vtimer)); > > - kvm_timer_unblocking(vcpu); > - > timer_restore_state(map.direct_vtimer); > if (map.direct_ptimer) > timer_restore_state(map.direct_ptimer); > @@ -668,6 +691,9 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > if (unlikely(!timer->enabled)) > return; > > + if (vcpu_is_rec(vcpu)) > + goto out; > + > get_timer_map(vcpu, &map); > > timer_save_state(map.direct_vtimer); > @@ -686,9 +712,6 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > if (map.emul_ptimer) > soft_timer_cancel(&map.emul_ptimer->hrtimer); > > - if (kvm_vcpu_is_blocking(vcpu)) > - kvm_timer_blocking(vcpu); > - > /* > * The kernel may decide to run userspace after calling vcpu_put, so > * we reset cntvoff to 0 to ensure a consistent read between user > @@ -697,6 +720,11 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > * virtual offset of zero, so no need to zero CNTVOFF_EL2 register. > */ > set_cntvoff(0); > + > +out: > + if (kvm_vcpu_is_blocking(vcpu)) > + kvm_timer_blocking(vcpu); > + > } > > /* > @@ -785,12 +813,18 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) > struct arch_timer_cpu *timer = vcpu_timer(vcpu); > struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); > struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); > + u64 cntvoff; > > vtimer->vcpu = vcpu; > ptimer->vcpu = vcpu; > > + if (kvm_is_realm(vcpu->kvm)) > + cntvoff = 0; > + else > + cntvoff = kvm_phys_timer_read(); > + > /* Synchronize cntvoff across all vtimers of a VM. */ > - update_vtimer_cntvoff(vcpu, kvm_phys_timer_read()); > + update_vtimer_cntvoff(vcpu, cntvoff); > timer_set_offset(ptimer, 0); > > hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); > @@ -1265,6 +1299,13 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu) > return -EINVAL; > } > > + /* > + * We don't use mapped IRQs for Realms because the RMI doesn't allow > + * us setting the LR.HW bit in the VGIC. > + */ > + if (vcpu_is_rec(vcpu)) > + return 0; > + > get_timer_map(vcpu, &map); > > ret = kvm_vgic_map_phys_irq(vcpu, > diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h > index cd6d8f260eab..158280e15a33 100644 > --- a/include/kvm/arm_arch_timer.h > +++ b/include/kvm/arm_arch_timer.h > @@ -76,6 +76,8 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); > int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); > int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); > > +void kvm_realm_timers_update(struct kvm_vcpu *vcpu); > + > u64 kvm_phys_timer_read(void); > > void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu);
Thanks, Ganapat
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