[patch 084/100] KVM: Interrupt mask notifiers for ioapic

Chris Wright
2009-04-23T07:52:53Z

[-- Attachment #1: kvm-interrupt-mask-notifiers-for-ioapic.patch --]
[-- Type: text/plain, Size: 4125 bytes --]

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Avi Kivity <avi@redhat.com>

upstream commit: 75858a84a6207f5e60196f6bbd18fde4250e5759

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.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---
include/linux/kvm_host.h | 17 +++++++++++++++++
virt/kvm/ioapic.c | 6 ++++++
virt/kvm/irq_comm.c | 24 ++++++++++++++++++++++++
virt/kvm/kvm_main.c | 3 +++
4 files changed, 50 insertions(+)

--- 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;
@@ -321,6 +325,19 @@ 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, 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, int irq, bool 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,
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -101,6 +101,7 @@ static void ioapic_service(struct kvm_io
static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
{
unsigned index;
+ bool mask_before, mask_after;

switch (ioapic->ioregsel) {
case IOAPIC_REG_VERSION:
@@ -120,6 +121,7 @@ static void ioapic_write_indirect(struct
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 +130,9 @@ static void ioapic_write_indirect(struct
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 +431,4 @@ int kvm_ioapic_init(struct kvm *kvm)
kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
return 0;
}
+
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -99,3 +99,27 @@ void kvm_free_irq_source_id(struct kvm *
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, bool 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);
+}
+
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -828,6 +828,9 @@ 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);