From 3607715a308d94b8c4797d23620e268a4c5bebf6 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 17 Oct 2019 12:12:35 +1100 Subject: [PATCH] kvm: Introduce KVM irqchip change notifier Awareness of an in kernel irqchip is usually local to the machine and its top-level interrupt controller. However, in a few cases other things need to know about it. In particular vfio devices need this in order to accelerate interrupt delivery. If interrupt routing is changed, such devices may need to readjust their connection to the KVM irqchip. pci_bus_fire_intx_routing_notifier() exists to do just this. However, for the pseries machine type we have a situation where the routing remains constant but the top-level irq chip itself is changed. This occurs because of PAPR feature negotiation which allows the guest to decide between the older XICS and newer XIVE irq chip models (both of which are paravirtualized). To allow devices like vfio to adjust to this change, introduce a new notifier for the purpose kvm_irqchip_change_notify(). Cc: Alex Williamson Cc: Alexey Kardashevskiy Signed-off-by: David Gibson Tested-by: Alex Williamson Reviewed-by: Alex Williamson Reviewed-by: Greg Kurz Acked-by: Alex Williamson --- accel/kvm/kvm-all.c | 18 ++++++++++++++++++ accel/stubs/kvm-stub.c | 12 ++++++++++++ include/sysemu/kvm.h | 5 +++++ 3 files changed, 35 insertions(+) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 140b0bd8f6..ca00daa2f5 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -149,6 +149,9 @@ static const KVMCapabilityInfo kvm_required_capabilites[] = { KVM_CAP_LAST_INFO }; +static NotifierList kvm_irqchip_change_notifiers = + NOTIFIER_LIST_INITIALIZER(kvm_irqchip_change_notifiers); + #define kvm_slots_lock(kml) qemu_mutex_lock(&(kml)->slots_lock) #define kvm_slots_unlock(kml) qemu_mutex_unlock(&(kml)->slots_lock) @@ -1396,6 +1399,21 @@ void kvm_irqchip_release_virq(KVMState *s, int virq) trace_kvm_irqchip_release_virq(virq); } +void kvm_irqchip_add_change_notifier(Notifier *n) +{ + notifier_list_add(&kvm_irqchip_change_notifiers, n); +} + +void kvm_irqchip_remove_change_notifier(Notifier *n) +{ + notifier_remove(n); +} + +void kvm_irqchip_change_notify(void) +{ + notifier_list_notify(&kvm_irqchip_change_notifiers, NULL); +} + static unsigned int kvm_hash_msi(uint32_t data) { /* This is optimized for IA32 MSI layout. However, no other arch shall diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c index 6feb66ed80..82f118d2df 100644 --- a/accel/stubs/kvm-stub.c +++ b/accel/stubs/kvm-stub.c @@ -138,6 +138,18 @@ void kvm_irqchip_commit_routes(KVMState *s) { } +void kvm_irqchip_add_change_notifier(Notifier *n) +{ +} + +void kvm_irqchip_remove_change_notifier(Notifier *n) +{ +} + +void kvm_irqchip_change_notify(void) +{ +} + int kvm_irqchip_add_adapter_route(KVMState *s, AdapterInfo *adapter) { return -ENOSYS; diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index 9d143282bc..9fe233b9bf 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -201,6 +201,7 @@ typedef struct KVMCapabilityInfo { struct KVMState; typedef struct KVMState KVMState; extern KVMState *kvm_state; +typedef struct Notifier Notifier; /* external API */ @@ -401,6 +402,10 @@ int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg); void kvm_irqchip_add_irq_route(KVMState *s, int gsi, int irqchip, int pin); +void kvm_irqchip_add_change_notifier(Notifier *n); +void kvm_irqchip_remove_change_notifier(Notifier *n); +void kvm_irqchip_change_notify(void); + void kvm_get_apic_state(DeviceState *d, struct kvm_lapic_state *kapic); struct kvm_guest_debug; -- 2.11.4.GIT