On Fri, 2014-07-11 at 10:10 +0800, ethan zhao wrote: > Alex, > Thanks for your reviewing, when I create the patch order, I thought > about the question you concerned for > quit a while, make every patch be independent to each other as possible > as I could, so we can do bisect when hit > problem. > > I manage to take more time to figure out better patch order. > > Thanks, > Ethan > > On 2014/7/11 9:48, Alex Williamson wrote: > > Since there's no 0th patch, I guess I'll comment here. This series is > > not bisectable, patch 1 breaks the existing implementation. I'd > > suggest: > > > > patch 1 - fix i40e > i40e only could be fixed with new interface, so it couldn't > be the first one.
It looks like i40e just has it's own copy of pci_vfs_assigned(), why can't your current patch 4/4 be applied now? > > patch 2 - create assign/deassign that uses dev_flags > This will be the first ? > > patch 3 - convert users to new interface > Have to be the later step. > > patch 4 - convert interface to use atomic_t > Could it be standalone step ? > > Let me think about it. > > > IMHO, the assigned flag is a horrible hack and I don't know why drivers > > like xenback need to use it. KVM needs to use it because it doesn't > > actually have a driver to bind to when a device is assigned, it's happy > > to assign devices without any driver. Thanks, > > > > Alex > > > > > > On Fri, 2014-07-11 at 08:47 +0800, Ethan Zhao wrote: > >> Current implementation of helper function pci_vfs_assigned() is a little > >> complex, to > >> get sum of VFs that assigned to VM, access low level configuration space > >> register and > >> then loop in traversing device tree. > >> > >> This patch introduce an atomic reference counter for VFs that assigned to > >> VM in struct > >> pci_sriov, and compose two more helper functions > >> > >> pci_sriov_assign_device(), > >> pci_sriov_deassign_device() > >> > >> to replace manipulation to device flag and the meanwhile increase and > >> decease the counter. > >> > >> Passed building on 3.15.5 > >> > >> Signed-off-by: Ethan Zhao <[email protected]> > >> --- > >> drivers/pci/iov.c | 65 > >> ++++++++++++++++++++++++++++---------------------- > >> drivers/pci/pci.h | 1 + > >> include/linux/pci.h | 4 +++ > >> 3 files changed, 41 insertions(+), 29 deletions(-) > >> > >> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > >> index de7a747..72e267f 100644 > >> --- a/drivers/pci/iov.c > >> +++ b/drivers/pci/iov.c > >> @@ -382,6 +382,7 @@ found: > >> iov->nres = nres; > >> iov->ctrl = ctrl; > >> iov->total_VFs = total; > >> + atomic_set(&iov->VFs_assigned_cnt, 0); > >> iov->offset = offset; > >> iov->stride = stride; > >> iov->pgsz = pgsz; > >> @@ -603,45 +604,51 @@ int pci_num_vf(struct pci_dev *dev) > >> EXPORT_SYMBOL_GPL(pci_num_vf); > >> > >> /** > >> - * pci_vfs_assigned - returns number of VFs are assigned to a guest > >> - * @dev: the PCI device > >> + * pci_vfs_assigned - returns number of VFs are assigned to VM > >> + * @dev: the physical PCI device that contains the VFs. > >> * > >> - * Returns number of VFs belonging to this device that are assigned to a > >> guest. > >> + * Returns number of VFs belonging to this device that are assigned to VM. > >> * If device is not a physical function returns 0. > >> */ > >> int pci_vfs_assigned(struct pci_dev *dev) > >> { > >> - struct pci_dev *vfdev; > >> - unsigned int vfs_assigned = 0; > >> - unsigned short dev_id; > >> - > >> - /* only search if we are a PF */ > >> if (!dev->is_physfn) > >> return 0; > >> + if (dev->sriov) > >> + return atomic_read(&dev->sriov->VFs_assigned_cnt); > >> + return 0; > >> +} > >> +EXPORT_SYMBOL_GPL(pci_vfs_assigned); > >> > >> - /* > >> - * determine the device ID for the VFs, the vendor ID will be the > >> - * same as the PF so there is no need to check for that one > >> - */ > >> - pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_VF_DID, &dev_id); > >> - > >> - /* loop through all the VFs to see if we own any that are assigned */ > >> - vfdev = pci_get_device(dev->vendor, dev_id, NULL); > >> - while (vfdev) { > >> - /* > >> - * It is considered assigned if it is a virtual function with > >> - * our dev as the physical function and the assigned bit is set > >> - */ > >> - if (vfdev->is_virtfn && (vfdev->physfn == dev) && > >> - (vfdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED)) > >> - vfs_assigned++; > >> - > >> - vfdev = pci_get_device(dev->vendor, dev_id, vfdev); > >> - } > >> +/** > >> + * pci_sriov_assign_device - assign device to VM > >> + * @pdev: the device to be assigned. > >> + */ > >> +void pci_sriov_assign_device(struct pci_dev *pdev) > >> +{ > >> + pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED; > >> + if (pdev->is_virtfn && !pdev->is_physfn) > >> + if (pdev->physfn) > >> + if (pdev->physfn->sriov) > >> + atomic_inc(&pdev->physfn->sriov-> > >> + VFs_assigned_cnt); > >> +} > >> +EXPORT_SYMBOL_GPL(pci_sriov_assign_device); > >> > >> - return vfs_assigned; > >> +/** > >> + * pci_sriov_deassign_device - deasign device from VM > >> + * @pdev: the device to be deassigned. > >> + */ > >> +void pci_sriov_deassign_device(struct pci_dev *pdev) > >> +{ > >> + pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED; > >> + if (pdev->is_virtfn && !pdev->is_physfn) > >> + if (pdev->physfn) > >> + if (pdev->physfn->sriov) > >> + atomic_dec(&pdev->physfn->sriov-> > >> + VFs_assigned_cnt); > >> } > >> -EXPORT_SYMBOL_GPL(pci_vfs_assigned); > >> +EXPORT_SYMBOL_GPL(pci_sriov_deassign_device); > >> > >> /** > >> * pci_sriov_set_totalvfs -- reduce the TotalVFs available > >> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > >> index 6bd0822..d17bda2 100644 > >> --- a/drivers/pci/pci.h > >> +++ b/drivers/pci/pci.h > >> @@ -235,6 +235,7 @@ struct pci_sriov { > >> u32 pgsz; /* page size for BAR alignment */ > >> u8 link; /* Function Dependency Link */ > >> u16 driver_max_VFs; /* max num VFs driver supports */ > >> + atomic_t VFs_assigned_cnt; /* counter of VFs assigned to VM */ > >> struct pci_dev *dev; /* lowest numbered PF */ > >> struct pci_dev *self; /* this PF */ > >> struct mutex lock; /* lock for VF bus */ > >> diff --git a/include/linux/pci.h b/include/linux/pci.h > >> index aab57b4..5cf6833 100644 > >> --- a/include/linux/pci.h > >> +++ b/include/linux/pci.h > >> @@ -1601,6 +1601,8 @@ int pci_enable_sriov(struct pci_dev *dev, int > >> nr_virtfn); > >> void pci_disable_sriov(struct pci_dev *dev); > >> int pci_num_vf(struct pci_dev *dev); > >> int pci_vfs_assigned(struct pci_dev *dev); > >> +void pci_sriov_assign_device(struct pci_dev *dev); > >> +void pci_sriov_deassign_device(struct pci_dev *dev); > >> int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs); > >> int pci_sriov_get_totalvfs(struct pci_dev *dev); > >> #else > >> @@ -1610,6 +1612,8 @@ static inline void pci_disable_sriov(struct pci_dev > >> *dev) { } > >> static inline int pci_num_vf(struct pci_dev *dev) { return 0; } > >> static inline int pci_vfs_assigned(struct pci_dev *dev) > >> { return 0; } > >> +static inline void pci_sriov_assign_device(struct pci_dev *dev) { } > >> +static inline void pci_sriov_deassign_device(struct pci_dev *dev) { } > >> static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs) > >> { return 0; } > >> static inline int pci_sriov_get_totalvfs(struct pci_dev *dev) > > > > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
