Commit cfecc291 authored by Tiwei Bie's avatar Tiwei Bie Committed by Michael S. Tsirkin
Browse files

virtio_pci: support enabling VFs 

There is a new feature bit allocated in virtio spec to
support SR-IOV (Single Root I/O Virtualization):

https://github.com/oasis-tcs/virtio-spec/issues/11



This patch enables the support for this feature bit in
virtio driver.

Signed-off-by: default avatarTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 670ae9ca

drivers/virtio/virtio_pci_common.c

+30 −0
Original line number Diff line number Diff line
@@ -577,6 +577,8 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) 
	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);

	struct device *dev = get_device(&vp_dev->vdev.dev);



	pci_disable_sriov(pci_dev);



	unregister_virtio_device(&vp_dev->vdev);



	if (vp_dev->ioaddr)
@@ -588,6 +590,33 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) 
	put_device(dev);

}



static int virtio_pci_sriov_configure(struct pci_dev *pci_dev, int num_vfs)

{

	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);

	struct virtio_device *vdev = &vp_dev->vdev;

	int ret;



	if (!(vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK))

		return -EBUSY;



	if (!__virtio_test_bit(vdev, VIRTIO_F_SR_IOV))

		return -EINVAL;



	if (pci_vfs_assigned(pci_dev))

		return -EPERM;



	if (num_vfs == 0) {

		pci_disable_sriov(pci_dev);

		return 0;

	}



	ret = pci_enable_sriov(pci_dev, num_vfs);

	if (ret < 0)

		return ret;



	return num_vfs;

}



static struct pci_driver virtio_pci_driver = {

	.name		= "virtio-pci",

	.id_table	= virtio_pci_id_table,
@@ -596,6 +625,7 @@ static struct pci_driver virtio_pci_driver = { 
#ifdef CONFIG_PM_SLEEP

	.driver.pm	= &virtio_pci_pm_ops,

#endif

	.sriov_configure = virtio_pci_sriov_configure,

};



module_pci_driver(virtio_pci_driver);

drivers/virtio/virtio_pci_modern.c

+14 −0
Original line number Diff line number Diff line
@@ -153,14 +153,28 @@ static u64 vp_get_features(struct virtio_device *vdev) 
	return features;

}



static void vp_transport_features(struct virtio_device *vdev, u64 features)

{

	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	struct pci_dev *pci_dev = vp_dev->pci_dev;



	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&

			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))

		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);

}



/* virtio config->finalize_features() implementation */

static int vp_finalize_features(struct virtio_device *vdev)

{

	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	u64 features = vdev->features;



	/* Give virtio_ring a chance to accept features. */

	vring_transport_features(vdev);



	/* Give virtio_pci a chance to accept features. */

	vp_transport_features(vdev, features);



	if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {

		dev_err(&vdev->dev, "virtio: device uses modern interface "

			"but does not have VIRTIO_F_VERSION_1\n");

include/uapi/linux/virtio_config.h

+6 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ 
 * transport being used (eg. virtio_ring), the rest are per-device feature

 * bits. */

#define VIRTIO_TRANSPORT_F_START	28

#define VIRTIO_TRANSPORT_F_END		34

#define VIRTIO_TRANSPORT_F_END		38



#ifndef VIRTIO_CONFIG_NO_LEGACY

/* Do we get callbacks when the ring is completely used, even if we've
@@ -71,4 +71,9 @@ 
 * this is for compatibility with legacy systems.

 */

#define VIRTIO_F_IOMMU_PLATFORM		33



/*

 * Does the device support Single Root I/O Virtualization?

 */

#define VIRTIO_F_SR_IOV			37

#endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */

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