Hi Dmytro,
On 8/5/22 21:39, Dmytro Maluka wrote:
> Currently irq mask notifiers are used only internally in the x86 code
> for PIT emulation. However they are not really arch specific. We are
> going to use them in the generic irqfd code, for postponing resampler
> irqfd notification until the interrupt is unmasked. So move the
> implementation of mask notifiers to the generic code, to allow irqfd to
> register its mask notifiers.
>
> Note that calling mask notifiers via calling kvm_fire_mask_notifiers()
> is still implemented for x86 only, so registering mask notifiers on
> other architectures will have no effect for now.
>
> Signed-off-by: Dmytro Maluka <dmy@xxxxxxxxxxxx>
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Eric
> ---
> arch/x86/include/asm/kvm_host.h | 16 ----------------
> arch/x86/kvm/irq_comm.c | 33 ---------------------------------
> arch/x86/kvm/x86.c | 1 -
> include/linux/kvm_host.h | 15 +++++++++++++++
> virt/kvm/eventfd.c | 33 +++++++++++++++++++++++++++++++++
> virt/kvm/kvm_main.c | 1 +
> 6 files changed, 49 insertions(+), 50 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 9217bd6cf0d1..dc76617f11c1 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1198,9 +1198,6 @@ struct kvm_arch {
>
> struct kvm_xen_hvm_config xen_hvm_config;
>
> - /* reads protected by irq_srcu, writes by irq_lock */
> - struct hlist_head mask_notifier_list;
> -
> struct kvm_hv hyperv;
> struct kvm_xen xen;
>
> @@ -1688,19 +1685,6 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3);
> int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
> const void *val, int bytes);
>
> -struct kvm_irq_mask_notifier {
> - void (*func)(struct kvm_irq_mask_notifier *kimn, bool masked);
> - int irq;
> - struct hlist_node link;
> -};
> -
> -void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
> - struct kvm_irq_mask_notifier *kimn);
> -void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
> - struct kvm_irq_mask_notifier *kimn);
> -void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
> - bool mask);
> -
> extern bool tdp_enabled;
>
> u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu);
> diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
> index 0687162c4f22..f27e4c9c403e 100644
> --- a/arch/x86/kvm/irq_comm.c
> +++ b/arch/x86/kvm/irq_comm.c
> @@ -234,39 +234,6 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
> mutex_unlock(&kvm->irq_lock);
> }
>
> -void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
> - struct kvm_irq_mask_notifier *kimn)
> -{
> - mutex_lock(&kvm->irq_lock);
> - kimn->irq = irq;
> - hlist_add_head_rcu(&kimn->link, &kvm->arch.mask_notifier_list);
> - mutex_unlock(&kvm->irq_lock);
> -}
> -
> -void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
> - struct kvm_irq_mask_notifier *kimn)
> -{
> - mutex_lock(&kvm->irq_lock);
> - hlist_del_rcu(&kimn->link);
> - mutex_unlock(&kvm->irq_lock);
> - synchronize_srcu(&kvm->irq_srcu);
> -}
> -
> -void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
> - bool mask)
> -{
> - struct kvm_irq_mask_notifier *kimn;
> - int idx, gsi;
> -
> - idx = srcu_read_lock(&kvm->irq_srcu);
> - gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
> - if (gsi != -1)
> - hlist_for_each_entry_rcu(kimn, &kvm->arch.mask_notifier_list, link)
> - if (kimn->irq == gsi)
> - kimn->func(kimn, mask);
> - srcu_read_unlock(&kvm->irq_srcu, idx);
> -}
> -
> bool kvm_arch_can_set_irq_routing(struct kvm *kvm)
> {
> return irqchip_in_kernel(kvm);
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index e5fa335a4ea7..a0a776f5c42f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -11818,7 +11818,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
> if (ret)
> goto out_page_track;
>
> - INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
> INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
> atomic_set(&kvm->arch.noncoherent_dma_count, 0);
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 90a45ef7203b..dd5f14e31996 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -760,7 +760,10 @@ struct kvm {
> struct kvm_irq_routing_table __rcu *irq_routing;
> #endif
> #ifdef CONFIG_HAVE_KVM_IRQFD
> + /* reads protected by irq_srcu, writes by irq_lock */
> struct hlist_head irq_ack_notifier_list;
> + /* reads protected by irq_srcu, writes by irq_lock */
> + struct hlist_head irq_mask_notifier_list;
> #endif
>
> #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
> @@ -1581,6 +1584,12 @@ struct kvm_irq_ack_notifier {
> void (*irq_acked)(struct kvm_irq_ack_notifier *kian);
> };
>
> +struct kvm_irq_mask_notifier {
> + void (*func)(struct kvm_irq_mask_notifier *kimn, bool masked);
> + int irq;
> + struct hlist_node link;
> +};
> +
> int kvm_irq_map_gsi(struct kvm *kvm,
> struct kvm_kernel_irq_routing_entry *entries, int gsi);
> int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin);
> @@ -1599,6 +1608,12 @@ void kvm_register_irq_ack_notifier(struct kvm *kvm,
> struct kvm_irq_ack_notifier *kian);
> void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
> struct kvm_irq_ack_notifier *kian);
> +void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
> + struct kvm_irq_mask_notifier *kimn);
> +void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
> + struct kvm_irq_mask_notifier *kimn);
> +void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
> + bool mask);
> int kvm_request_irq_source_id(struct kvm *kvm);
> void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
> bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index 2a3ed401ce46..39403d9fbdcc 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -518,6 +518,39 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
> synchronize_srcu(&kvm->irq_srcu);
> kvm_arch_post_irq_ack_notifier_list_update(kvm);
> }
> +
> +void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
> + struct kvm_irq_mask_notifier *kimn)
> +{
> + mutex_lock(&kvm->irq_lock);
> + kimn->irq = irq;
> + hlist_add_head_rcu(&kimn->link, &kvm->irq_mask_notifier_list);
> + mutex_unlock(&kvm->irq_lock);
> +}
> +
> +void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
> + struct kvm_irq_mask_notifier *kimn)
> +{
> + mutex_lock(&kvm->irq_lock);
> + hlist_del_rcu(&kimn->link);
> + mutex_unlock(&kvm->irq_lock);
> + synchronize_srcu(&kvm->irq_srcu);
> +}
> +
> +void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
> + bool mask)
> +{
> + struct kvm_irq_mask_notifier *kimn;
> + int idx, gsi;
> +
> + idx = srcu_read_lock(&kvm->irq_srcu);
> + gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
> + if (gsi != -1)
> + hlist_for_each_entry_rcu(kimn, &kvm->irq_mask_notifier_list, link)
> + if (kimn->irq == gsi)
> + kimn->func(kimn, mask);
> + srcu_read_unlock(&kvm->irq_srcu, idx);
> +}
> #endif
>
> void
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index a49df8988cd6..5ca7fb0b8257 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1144,6 +1144,7 @@ static struct kvm *kvm_create_vm(unsigned long type)
>
> #ifdef CONFIG_HAVE_KVM_IRQFD
> INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
> + INIT_HLIST_HEAD(&kvm->irq_mask_notifier_list);
> #endif
>
> r = kvm_init_mmu_notifier(kvm);
