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KVM: Fix guest shared interrupt with in-kernel irqchip

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Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Sheng Yang
2008-10-15 20:15:06 +08:00
committed by Avi Kivity
parent 6ad9f15c94
commit 5550af4df1
9 changed files with 79 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
virt/kvm/irq_comm.c
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@@ -25,15 +25,23 @@
#include "ioapic.h"
/* This should be called with the kvm->lock mutex held */
void kvm_set_irq(struct kvm *kvm, int irq, int level)
void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
{
unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
/* Logical OR for level trig interrupt */
if (level)
set_bit(irq_source_id, irq_state);
else
clear_bit(irq_source_id, irq_state);
/* Not possible to detect if the guest uses the PIC or the
* IOAPIC. So set the bit in both. The guest will ignore
* writes to the unused one.
*/
kvm_ioapic_set_irq(kvm->arch.vioapic, irq, level);
kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state));
#ifdef CONFIG_X86
kvm_pic_set_irq(pic_irqchip(kvm), irq, level);
kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state));
#endif
}
@@ -58,3 +66,31 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
{
hlist_del(&kian->link);
}
/* The caller must hold kvm->lock mutex */
int kvm_request_irq_source_id(struct kvm *kvm)
{
unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
int irq_source_id = find_first_zero_bit(bitmap,
sizeof(kvm->arch.irq_sources_bitmap));
if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
irq_source_id = -EFAULT;
} else
set_bit(irq_source_id, bitmap);
return irq_source_id;
}
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
{
int i;
if (irq_source_id <= 0 ||
irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
return;
}
for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
}