Commit 17071fe7 authored by Sheng Yang's avatar Sheng Yang Committed by Avi Kivity
Browse files

KVM: Add support to disable MSI for assigned device 



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: default avatarSheng Yang <sheng@linux.intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 67346440

include/linux/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -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

virt/kvm/kvm_main.c

+16 −2
Original line number Diff line number Diff line
@@ -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);

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