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Commit 6b9cc7fd authored by Sheng Yang's avatar Sheng Yang Committed by Avi Kivity
Browse files

KVM: Enable MSI for device assignment 



We enable guest MSI and host MSI support in this patch. The userspace want to
enable MSI should set KVM_DEV_IRQ_ASSIGN_ENABLE_MSI in the assigned_irq's flag.
Function would return -ENOTTY if can't enable MSI, userspace shouldn't set MSI
Enable bit when KVM_ASSIGN_IRQ return -ENOTTY with
KVM_DEV_IRQ_ASSIGN_ENABLE_MSI.

Userspace can tell the support of MSI device from #ifdef KVM_CAP_DEVICE_MSI.

Signed-off-by: default avatarSheng Yang <sheng@linux.intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent f64769eb

include/linux/kvm.h

+3 −0
Original line number Diff line number Diff line
@@ -392,6 +392,9 @@ struct kvm_trace_rec { 
#endif

#define KVM_CAP_IOMMU 18

#define KVM_CAP_NMI 19

#if defined(CONFIG_X86)

#define KVM_CAP_DEVICE_MSI 20

#endif



/*

 * ioctls for VM fds

virt/kvm/kvm_main.c

+75 −6
Original line number Diff line number Diff line
@@ -159,9 +159,15 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) 
	 * finer-grained lock, update this

	 */

	mutex_lock(&assigned_dev->kvm->lock);

	if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_INTX)

		kvm_set_irq(assigned_dev->kvm,

			    assigned_dev->irq_source_id,

			    assigned_dev->guest_irq, 1);

	else if (assigned_dev->irq_requested_type &

				KVM_ASSIGNED_DEV_GUEST_MSI) {

		assigned_device_msi_dispatch(assigned_dev);

		enable_irq(assigned_dev->host_irq);

	}

	mutex_unlock(&assigned_dev->kvm->lock);

	kvm_put_kvm(assigned_dev->kvm);

}
@@ -197,6 +203,8 @@ static void kvm_free_assigned_device(struct kvm *kvm, 
{

	if (irqchip_in_kernel(kvm) && assigned_dev->irq_requested_type)

		free_irq(assigned_dev->host_irq, (void *)assigned_dev);

	if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)

		pci_disable_msi(assigned_dev->dev);



	kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier);

	kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
@@ -242,6 +250,11 @@ static int assigned_device_update_intx(struct kvm *kvm, 
		return 0;



	if (irqchip_in_kernel(kvm)) {

		if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) {

			free_irq(adev->host_irq, (void *)kvm);

			pci_disable_msi(adev->dev);

		}



		if (!capable(CAP_SYS_RAWIO))

			return -EPERM;
@@ -265,6 +278,41 @@ static int assigned_device_update_intx(struct kvm *kvm, 
	return 0;

}



#ifdef CONFIG_X86

static int assigned_device_update_msi(struct kvm *kvm,

			struct kvm_assigned_dev_kernel *adev,

			struct kvm_assigned_irq *airq)

{

	int r;



	/* x86 don't care upper address of guest msi message addr */

	adev->guest_msi.address_lo = airq->guest_msi.addr_lo;

	adev->guest_msi.data = airq->guest_msi.data;

	adev->ack_notifier.gsi = -1;



	if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)

		return 0;



	if (irqchip_in_kernel(kvm)) {

		if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)

			free_irq(adev->host_irq, (void *)adev);



		r = pci_enable_msi(adev->dev);

		if (r)

			return r;



		adev->host_irq = adev->dev->irq;

		if (request_irq(adev->host_irq, kvm_assigned_dev_intr, 0,

				"kvm_assigned_msi_device", (void *)adev))

			return -EIO;

	}



	adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI |

				   KVM_ASSIGNED_DEV_HOST_MSI;

	return 0;

}

#endif



static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,

				   struct kvm_assigned_irq

				   *assigned_irq)
@@ -301,9 +349,30 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm, 
		}

	}



	if (assigned_irq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {

#ifdef CONFIG_X86

		r = assigned_device_update_msi(kvm, match, assigned_irq);

		if (r) {

			printk(KERN_WARNING "kvm: failed to enable "

					"MSI device!\n");

			goto out_release;

		}

#else

		r = -ENOTTY;

#endif

	} else if (assigned_irq->host_irq == 0 && match->dev->irq == 0) {

		/* Host device IRQ 0 means don't support INTx */

		printk(KERN_WARNING "kvm: wait device to enable MSI!\n");

		r = 0;

	} else {

		/* Non-sharing INTx mode */

		r = assigned_device_update_intx(kvm, match, assigned_irq);

	if (r)

		if (r) {

			printk(KERN_WARNING "kvm: failed to enable "

					"INTx device!\n");

			goto out_release;

		}

	}



	mutex_unlock(&kvm->lock);

	return r;