On Wed, Jun 06, 2018 at 08:11:54PM +0800, Tiwei Bie wrote: > On Tue, Jun 05, 2018 at 03:23:11PM +0300, Michael S. Tsirkin wrote: > > On Tue, Jun 05, 2018 at 09:36:53AM +0800, Tiwei Bie wrote: > > > On Mon, Jun 04, 2018 at 07:32:25PM +0300, Michael S. Tsirkin wrote: > > > > 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? > > > > So for restore, don't you need to restore the > > sriov capability? > > Currently I'm not familiar with the PM part. > But I still think the sriov capability should > be handled by PCI core. OK but the point is restore looks just like power up for device. > I'm trying to understand > all the relevant code.. > For your question, based on what I found from > the code currently, I guess the sriov capability > will be restored by pci_restore_state() which > will be called by the ops in pci_dev_pm_ops. > The sriov_restore_state() will be called > eventually. > > Best regards, > Tiwei Bie Right but my point is during resume SRIOV gets enabled first before driver ok. Maybe we should relax the requirements in the spec: - only require FEATURES_OK from device, not DRIVER_OK from driver - explain that it only has to happen once, not on each reset, and driver can remember the result > > > > > > > > > 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 think VFs are managed by PCI core. Once they are > > > allocated, virtio driver doesn't have to care too > > > much about how to manage them. The proposal for the > > > spec is just to provide a feature bit based virtio > > > way for virtio drivers to know whether a virtio > > > device is SR-IOV capable (and virtio drivers can > > > support configuring SR-IOV based on the feature > > > bit negotiation result). > > > > > > > > > > > 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? > > > > > > Sorry, currently I don't have anything like this.. > > > > > > Best regards, > > > Tiwei Bie > > > > > > > > > > > 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 > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@xxxxxxxxxxxxxxxxxxxx > > > > For additional commands, e-mail: virtio-dev-help@xxxxxxxxxxxxxxxxxxxx > > > > _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
