From: Sheng Yang <[EMAIL PROTECTED]>
Keep a record of current interrupt state before injecting. Don't
assert/deassert repeatedly, so that every caller of kvm_set_irq()
can be identified as a separate interrupt source for the IOAPIC/PIC
to implement logical OR of level triggered interrupts on one IRQ line.
Notice that userspace devices are treated as one device for each IRQ
line. The correctness of sharing interrupt for each IRQ line should be
ensured by the userspace program (QEmu).
[Amit: rebase to kvm.git HEAD]
Signed-off-by: Sheng Yang <[EMAIL PROTECTED]>
Signed-off-by: Amit Shah <[EMAIL PROTECTED]>
---
arch/x86/kvm/x86.c | 13 ++++++++++++-
include/linux/kvm_host.h | 3 +++
virt/kvm/kvm_main.c | 12 +++++++++---
3 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dda478e..6f45428 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1816,7 +1816,18 @@ long kvm_arch_vm_ioctl(struct file *filp,
goto out;
if (irqchip_in_kernel(kvm)) {
mutex_lock(&kvm->lock);
- kvm_set_irq(kvm, irq_event.irq, irq_event.level);
+ /*
+ * Take one IRQ line as from one device, shared IRQ
+ * line should also be handled in the userspace before
+ * use KVM_IRQ_LINE ioctl to change IRQ line state.
+ */
+ if (kvm->userspace_intrsource_states[irq_event.irq]
+ != irq_event.level) {
+ kvm_set_irq(kvm, irq_event.irq,
+ irq_event.level);
+ kvm->userspace_intrsource_states[irq_event.irq]
+ = irq_event.level;
+ }
mutex_unlock(&kvm->lock);
r = 0;
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 3833c48..d392e31 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -129,6 +129,8 @@ struct kvm {
unsigned long mmu_notifier_seq;
long mmu_notifier_count;
#endif
+
+ int userspace_intrsource_states[KVM_IOAPIC_NUM_PINS];
};
/* The guest did something we don't support. */
@@ -306,6 +308,7 @@ struct kvm_assigned_dev_kernel {
int host_irq;
int guest_irq;
int irq_requested;
+ int irq_state;
struct pci_dev *dev;
struct kvm *kvm;
};
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cf0ab8e..faa56fb 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -104,8 +104,11 @@ static void kvm_assigned_dev_interrupt_work_handler(struct
work_struct *work)
* finer-grained lock, update this
*/
mutex_lock(&assigned_dev->kvm->lock);
- kvm_set_irq(assigned_dev->kvm,
- assigned_dev->guest_irq, 1);
+ if (assigned_dev->irq_state == 0) {
+ kvm_set_irq(assigned_dev->kvm,
+ assigned_dev->guest_irq, 1);
+ assigned_dev->irq_state = 1;
+ }
mutex_unlock(&assigned_dev->kvm->lock);
kvm_put_kvm(assigned_dev->kvm);
}
@@ -134,7 +137,10 @@ static void kvm_assigned_dev_ack_irq(struct
kvm_irq_ack_notifier *kian)
dev = container_of(kian, struct kvm_assigned_dev_kernel,
ack_notifier);
- kvm_set_irq(dev->kvm, dev->guest_irq, 0);
+ if (dev->irq_state == 1) {
+ kvm_set_irq(dev->kvm, dev->guest_irq, 0);
+ dev->irq_state = 0;
+ }
enable_irq(dev->host_irq);
}
--
1.5.4.3
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