On Monday 05 January 2009 00:14:44 Avi Kivity wrote:
> Allow clients to request notifications when the guest masks or unmasks a
> particular irq line. This complements irq ack notifications, as the guest
> will not ack an irq line that is masked.
>
> Currently implemented for the ioapic only.
Hi Avi
Need a lock for this list? Seems kvm_fire_mask_notifiers() implicit holding
kvm->lock, but register/unregister didn't. And I think we need some comments
for the necessary of lock.
--
regards
Yang, Sheng
>
> Signed-off-by: Avi Kivity <a...@redhat.com>
> ---
> include/linux/kvm_host.h | 17 +++++++++++++++++
> virt/kvm/ioapic.c | 7 ++++++-
> virt/kvm/irq_comm.c | 24 ++++++++++++++++++++++++
> virt/kvm/kvm_main.c | 3 +++
> 4 files changed, 50 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 545a133..43385fa 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -127,6 +127,10 @@ struct kvm {
> struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
> #endif
>
> +#ifdef CONFIG_HAVE_KVM_IRQCHIP
> + struct hlist_head mask_notifier_list;
> +#endif
> +
> #ifdef KVM_ARCH_WANT_MMU_NOTIFIER
> struct mmu_notifier mmu_notifier;
> unsigned long mmu_notifier_seq;
> @@ -320,6 +324,19 @@ struct kvm_assigned_dev_kernel {
> struct pci_dev *dev;
> struct kvm *kvm;
> };
> +
> +struct kvm_irq_mask_notifier {
> + void (*func)(struct kvm_irq_mask_notifier *kimn, int 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, int irq, int mask);
> +
> void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
> void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi);
> void kvm_register_irq_ack_notifier(struct kvm *kvm,
> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
> index 23b81cf..15b9ddd 100644
> --- a/virt/kvm/ioapic.c
> +++ b/virt/kvm/ioapic.c
> @@ -100,7 +100,7 @@ static void ioapic_service(struct kvm_ioapic *ioapic,
> unsigned int idx)
>
> static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
> {
> - unsigned index;
> + unsigned index, mask_before, mask_after;
>
> switch (ioapic->ioregsel) {
> case IOAPIC_REG_VERSION:
> @@ -120,6 +120,7 @@ static void ioapic_write_indirect(struct kvm_ioapic
> *ioapic, u32 val) ioapic_debug("change redir index %x val %x\n", index,
> val);
> if (index >= IOAPIC_NUM_PINS)
> return;
> + mask_before = ioapic->redirtbl[index].fields.mask;
> if (ioapic->ioregsel & 1) {
> ioapic->redirtbl[index].bits &= 0xffffffff;
> ioapic->redirtbl[index].bits |= (u64) val << 32;
> @@ -128,6 +129,9 @@ static void ioapic_write_indirect(struct kvm_ioapic
> *ioapic, u32 val) ioapic->redirtbl[index].bits |= (u32) val;
> ioapic->redirtbl[index].fields.remote_irr = 0;
> }
> + mask_after = ioapic->redirtbl[index].fields.mask;
> + if (mask_before != mask_after)
> + kvm_fire_mask_notifiers(ioapic->kvm, index, mask_after);
> if (ioapic->irr & (1 << index))
> ioapic_service(ioapic, index);
> break;
> @@ -426,3 +430,4 @@ int kvm_ioapic_init(struct kvm *kvm)
> kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
> return 0;
> }
> +
> diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
> index aa5d1e5..2cbde68 100644
> --- a/virt/kvm/irq_comm.c
> +++ b/virt/kvm/irq_comm.c
> @@ -99,3 +99,27 @@ void kvm_free_irq_source_id(struct kvm *kvm, int
> irq_source_id) clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
> clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
> }
> +
> +void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
> + struct kvm_irq_mask_notifier *kimn)
> +{
> + kimn->irq = irq;
> + hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
> +}
> +
> +void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
> + struct kvm_irq_mask_notifier *kimn)
> +{
> + hlist_del(&kimn->link);
> +}
> +
> +void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, int mask)
> +{
> + struct kvm_irq_mask_notifier *kimn;
> + struct hlist_node *n;
> +
> + hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
> + if (kimn->irq == irq)
> + kimn->func(kimn, mask);
> +}
> +
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 5703557..dcd58d6 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -806,6 +806,9 @@ static struct kvm *kvm_create_vm(void)
>
> if (IS_ERR(kvm))
> goto out;
> +#ifdef CONFIG_HAVE_KVM_IRQCHIP
> + INIT_HLIST_HEAD(&kvm->mask_notifier_list);
> +#endif
>
> #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
> page = alloc_page(GFP_KERNEL | __GFP_ZERO);
--
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