KVM: PPC: booke: Improve timer register emulation
Decrementers are now properly driven by TCR/TSR, and the guest
has full read/write access to these registers.
The decrementer keeps ticking (and setting the TSR bit) regardless of
whether the interrupts are enabled with TCR.
The decrementer stops at zero, rather than going negative.
Decrementers (and FITs, once implemented) are delivered as
level-triggered interrupts -- dequeued when the TSR bit is cleared, not
on delivery.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
[scottwood@freescale.com: significant changes]
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 50803dd..9e41f45 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -252,9 +252,11 @@
allowed = vcpu->arch.shared->msr & MSR_ME;
msr_mask = 0;
break;
- case BOOKE_IRQPRIO_EXTERNAL:
case BOOKE_IRQPRIO_DECREMENTER:
case BOOKE_IRQPRIO_FIT:
+ keep_irq = true;
+ /* fall through */
+ case BOOKE_IRQPRIO_EXTERNAL:
allowed = vcpu->arch.shared->msr & MSR_EE;
allowed = allowed && !crit;
msr_mask = MSR_CE|MSR_ME|MSR_DE;
@@ -282,11 +284,26 @@
return allowed;
}
+static void update_timer_ints(struct kvm_vcpu *vcpu)
+{
+ if ((vcpu->arch.tcr & TCR_DIE) && (vcpu->arch.tsr & TSR_DIS))
+ kvmppc_core_queue_dec(vcpu);
+ else
+ kvmppc_core_dequeue_dec(vcpu);
+}
+
static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
{
unsigned long *pending = &vcpu->arch.pending_exceptions;
unsigned int priority;
+ if (vcpu->requests) {
+ if (kvm_check_request(KVM_REQ_PENDING_TIMER, vcpu)) {
+ smp_mb();
+ update_timer_ints(vcpu);
+ }
+ }
+
priority = __ffs(*pending);
while (priority <= BOOKE_IRQPRIO_MAX) {
if (kvmppc_booke_irqprio_deliver(vcpu, priority))
@@ -749,25 +766,16 @@
vcpu->arch.shared->esr = sregs->u.e.esr;
vcpu->arch.shared->dar = sregs->u.e.dear;
vcpu->arch.vrsave = sregs->u.e.vrsave;
- vcpu->arch.tcr = sregs->u.e.tcr;
+ kvmppc_set_tcr(vcpu, sregs->u.e.tcr);
- if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_DEC)
+ if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_DEC) {
vcpu->arch.dec = sregs->u.e.dec;
-
- kvmppc_emulate_dec(vcpu);
+ kvmppc_emulate_dec(vcpu);
+ }
if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_TSR) {
- /*
- * FIXME: existing KVM timer handling is incomplete.
- * TSR cannot be read by the guest, and its value in
- * vcpu->arch is always zero. For now, just handle
- * the case where the caller is trying to inject a
- * decrementer interrupt.
- */
-
- if ((sregs->u.e.tsr & TSR_DIS) &&
- (vcpu->arch.tcr & TCR_DIE))
- kvmppc_core_queue_dec(vcpu);
+ vcpu->arch.tsr = sregs->u.e.tsr;
+ update_timer_ints(vcpu);
}
return 0;
@@ -923,6 +931,33 @@
{
}
+void kvmppc_set_tcr(struct kvm_vcpu *vcpu, u32 new_tcr)
+{
+ vcpu->arch.tcr = new_tcr;
+ update_timer_ints(vcpu);
+}
+
+void kvmppc_set_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
+{
+ set_bits(tsr_bits, &vcpu->arch.tsr);
+ smp_wmb();
+ kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
+ kvm_vcpu_kick(vcpu);
+}
+
+void kvmppc_clr_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
+{
+ clear_bits(tsr_bits, &vcpu->arch.tsr);
+ update_timer_ints(vcpu);
+}
+
+void kvmppc_decrementer_func(unsigned long data)
+{
+ struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
+
+ kvmppc_set_tsr_bits(vcpu, TSR_DIS);
+}
+
int __init kvmppc_booke_init(void)
{
unsigned long ivor[16];