kvm/x86: Hyper-V SynIC timers

Per Hyper-V specification (and as required by Hyper-V-aware guests),
SynIC provides 4 per-vCPU timers.  Each timer is programmed via a pair
of MSRs, and signals expiration by delivering a special format message
to the configured SynIC message slot and triggering the corresponding
synthetic interrupt.

Note: as implemented by this patch, all periodic timers are "lazy"
(i.e. if the vCPU wasn't scheduled for more than the timer period the
timer events are lost), regardless of the corresponding configuration
MSR.  If deemed necessary, the "catch up" mode (the timer period is
shortened until the timer catches up) will be implemented later.

Changes v2:
* Use remainder to calculate periodic timer expiration time

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index d5d8217c59bba..60eccd4bd1d36 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -59,5 +59,29 @@ void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector);
 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu);
 
 void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu);
+void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu);
+
+static inline struct kvm_vcpu_hv_stimer *vcpu_to_stimer(struct kvm_vcpu *vcpu,
+							int timer_index)
+{
+	return &vcpu_to_hv_vcpu(vcpu)->stimer[timer_index];
+}
+
+static inline struct kvm_vcpu *stimer_to_vcpu(struct kvm_vcpu_hv_stimer *stimer)
+{
+	struct kvm_vcpu_hv *hv_vcpu;
+
+	hv_vcpu = container_of(stimer - stimer->index, struct kvm_vcpu_hv,
+			       stimer[0]);
+	return hv_vcpu_to_vcpu(hv_vcpu);
+}
+
+static inline bool kvm_hv_has_stimer_pending(struct kvm_vcpu *vcpu)
+{
+	return !bitmap_empty(vcpu->arch.hyperv.stimer_pending_bitmap,
+			     HV_SYNIC_STIMER_COUNT);
+}
+
+void kvm_hv_process_stimers(struct kvm_vcpu *vcpu);
 
 #endif