On Fri, Jun 01, 2018 at 12:02:39PM +0800, Tiwei Bie wrote: > 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: Tiwei Bie <tiwei.bie@xxxxxxxxx> > --- OK but what about freeze/restore functions? I also wonder about kexec - virtio.c currently does: /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ dev->config->reset(dev); Do we need to do something like this for sriov? I also wonder whether PCI core should disable sriov for us. I wish there was a patch emulating this without vDPA for QEMU, would make it easy to test your patches. Do you happen to have something like this? Thanks, > v3: > - Drop the acks; > > v2: > - Disable VFs when unbinding the driver (Alex, MST); > - Don't use pci_sriov_configure_simple (Alex); > > drivers/virtio/virtio_pci_common.c | 30 ++++++++++++++++++++++++++++++ > drivers/virtio/virtio_pci_modern.c | 14 ++++++++++++++ > include/uapi/linux/virtio_config.h | 7 ++++++- > 3 files changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > index 48d4d1cf1cb6..1d4467b2dc31 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -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); > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c > index 2555d80f6eec..07571daccfec 100644 > --- a/drivers/virtio/virtio_pci_modern.c > +++ b/drivers/virtio/virtio_pci_modern.c > @@ -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"); > diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h > index 308e2096291f..b7c1f4e7d59e 100644 > --- a/include/uapi/linux/virtio_config.h > +++ b/include/uapi/linux/virtio_config.h > @@ -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 */ > -- > 2.17.0
