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KVM: Add support to disable MSI for assigned device

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MSI is always enabled by default for msi2intx=1. But if msi2intx=0, we
have to disable MSI if guest require to do so.

The patch also discard unnecessary msi2intx judgment if guest want to update
MSI state.

Notice KVM_DEV_IRQ_ASSIGN_MSI_ACTION is a mask which should cover all MSI
related operations, though we only got one for now.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Sheng Yang 2009-01-06 16:25:11 +08:00 committed by Avi Kivity
parent 67346440e8
commit 17071fe74f
2 changed files with 17 additions and 2 deletions
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1
include/linux/kvm.h
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@ -550,6 +550,7 @@ struct kvm_assigned_irq {
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_IRQ_ASSIGN_MSI_ACTION KVM_DEV_IRQ_ASSIGN_ENABLE_MSI
#define KVM_DEV_IRQ_ASSIGN_ENABLE_MSI (1 << 0)
#endif

18
virt/kvm/kvm_main.c
View File

@ -343,6 +343,14 @@ static int assigned_device_update_msi(struct kvm *kvm,
adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_MSI;
adev->guest_irq = airq->guest_irq;
adev->ack_notifier.gsi = airq->guest_irq;
} else {
/*
* Guest require to disable device MSI, we disable MSI and
* re-enable INTx by default again. Notice it's only for
* non-msi2intx.
*/
assigned_device_update_intx(kvm, adev, airq);
return 0;
}
if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
@ -379,6 +387,7 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
{
int r = 0;
struct kvm_assigned_dev_kernel *match;
u32 current_flags = 0, changed_flags;
mutex_lock(&kvm->lock);
@ -416,8 +425,13 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
}
}
if ((!msi2intx &&
(assigned_irq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI)) ||
if ((match->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) &&
(match->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_MSI))
current_flags |= KVM_DEV_IRQ_ASSIGN_ENABLE_MSI;
changed_flags = assigned_irq->flags ^ current_flags;
if ((changed_flags & KVM_DEV_IRQ_ASSIGN_MSI_ACTION) ||
(msi2intx && match->dev->msi_enabled)) {
#ifdef CONFIG_X86
r = assigned_device_update_msi(kvm, match, assigned_irq);