Re: [PATCH 1/3] pci-iov: Add support for unmanaged SR-IOV
On Fri, Mar 2, 2018 at 3:59 PM, Alex Williamson wrote: > On Fri, 02 Mar 2018 15:44:25 -0800 > Alexander Duyck wrote: > >> From: Alexander Duyck >> >> This patch is meant to add some basic functionality to support for SR-IOV >> on devices when the VFs are not managed by the kernel. The functions >> provided here can be used by drivers such as vfio-pci and virtio to enable >> SR-IOV on devices that are either managed by userspace, or by some sort of >> firmware entity respectively. >> >> A new sysfs value called sriov_unmanaged_autoprobe has been added. This >> value is used as the drivers_autoprobe setting of the VFs when they are >> being managed by an external entity such as userspace or device firmware >> instead of being managed by the kernel. >> >> One side effect of this change is that the sriov_drivers_autoprobe and >> sriov_unmanaged_autoprobe will only apply their updates when SR-IOV is >> disabled. Attempts to update them when SR-IOV is in use will only update >> the local value and will not update sriov->autoprobe. >> >> Signed-off-by: Alexander Duyck >> --- >> Documentation/ABI/testing/sysfs-bus-pci | 17 ++ >> drivers/pci/iov.c | 37 >> +++ >> drivers/pci/pci-driver.c|2 +- >> drivers/pci/pci-sysfs.c | 29 >> drivers/pci/pci.h |4 +++ >> include/linux/pci.h |1 + >> 6 files changed, 88 insertions(+), 2 deletions(-) >> >> diff --git a/Documentation/ABI/testing/sysfs-bus-pci >> b/Documentation/ABI/testing/sysfs-bus-pci >> index 44d4b2be92fd..ff0b6c19cb1a 100644 >> --- a/Documentation/ABI/testing/sysfs-bus-pci >> +++ b/Documentation/ABI/testing/sysfs-bus-pci >> @@ -323,3 +323,20 @@ Description: >> >> This is similar to /sys/bus/pci/drivers_autoprobe, but >> affects only the VFs associated with a specific PF. >> + >> +What:/sys/bus/pci/devices/.../sriov_unmanaged_autoprobe >> +Date:March 2018 >> +Contact: Alexander Duyck >> +Description: >> + This file is associated with the PF of a device that >> + supports SR-IOV. It determines whether newly-enabled VFs >> + are immediately bound to a driver when the PF driver does >> + not manage the VFs itself. It initially contains 0, which >> + means the kernel will not automatically bind VFs to a driver. >> + If an application writes 1 to the file before enabling VFs, >> + the kernel will bind VFs to a compatible driver immediately >> + after they are enabled. >> + >> + This overrides /sys/bus/pci/devices/.../sriov_drivers_autoprobe >> + when a PF driver is not present to manage a device, or the PF >> + driver does not provide functionality to support SR-IOV. > > > Given a pf, how does a user determine whether it is managed or unmanaged > and therefore which autoprobe attributes are in effect? Thanks, > > Alex Basically it comes down to what driver is loaded on it. For now vfio-pci and virtio would be the only two using the "unmanaged" version of things. Really you don't know which autoprobe is in effect until SR-IOV is enabled by whatever driver. As such you should really be setting both the drivers_autoprobe and the unmanaged_autoprobe based on the expected use case. - Alex
Re: [PATCH 1/3] pci-iov: Add support for unmanaged SR-IOV
On Fri, 02 Mar 2018 15:44:25 -0800 Alexander Duyck wrote: > From: Alexander Duyck > > This patch is meant to add some basic functionality to support for SR-IOV > on devices when the VFs are not managed by the kernel. The functions > provided here can be used by drivers such as vfio-pci and virtio to enable > SR-IOV on devices that are either managed by userspace, or by some sort of > firmware entity respectively. > > A new sysfs value called sriov_unmanaged_autoprobe has been added. This > value is used as the drivers_autoprobe setting of the VFs when they are > being managed by an external entity such as userspace or device firmware > instead of being managed by the kernel. > > One side effect of this change is that the sriov_drivers_autoprobe and > sriov_unmanaged_autoprobe will only apply their updates when SR-IOV is > disabled. Attempts to update them when SR-IOV is in use will only update > the local value and will not update sriov->autoprobe. > > Signed-off-by: Alexander Duyck > --- > Documentation/ABI/testing/sysfs-bus-pci | 17 ++ > drivers/pci/iov.c | 37 > +++ > drivers/pci/pci-driver.c|2 +- > drivers/pci/pci-sysfs.c | 29 > drivers/pci/pci.h |4 +++ > include/linux/pci.h |1 + > 6 files changed, 88 insertions(+), 2 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-pci > b/Documentation/ABI/testing/sysfs-bus-pci > index 44d4b2be92fd..ff0b6c19cb1a 100644 > --- a/Documentation/ABI/testing/sysfs-bus-pci > +++ b/Documentation/ABI/testing/sysfs-bus-pci > @@ -323,3 +323,20 @@ Description: > > This is similar to /sys/bus/pci/drivers_autoprobe, but > affects only the VFs associated with a specific PF. > + > +What:/sys/bus/pci/devices/.../sriov_unmanaged_autoprobe > +Date:March 2018 > +Contact: Alexander Duyck > +Description: > + This file is associated with the PF of a device that > + supports SR-IOV. It determines whether newly-enabled VFs > + are immediately bound to a driver when the PF driver does > + not manage the VFs itself. It initially contains 0, which > + means the kernel will not automatically bind VFs to a driver. > + If an application writes 1 to the file before enabling VFs, > + the kernel will bind VFs to a compatible driver immediately > + after they are enabled. > + > + This overrides /sys/bus/pci/devices/.../sriov_drivers_autoprobe > + when a PF driver is not present to manage a device, or the PF > + driver does not provide functionality to support SR-IOV. Given a pf, how does a user determine whether it is managed or unmanaged and therefore which autoprobe attributes are in effect? Thanks, Alex
[PATCH 1/3] pci-iov: Add support for unmanaged SR-IOV
From: Alexander Duyck
This patch is meant to add some basic functionality to support for SR-IOV
on devices when the VFs are not managed by the kernel. The functions
provided here can be used by drivers such as vfio-pci and virtio to enable
SR-IOV on devices that are either managed by userspace, or by some sort of
firmware entity respectively.
A new sysfs value called sriov_unmanaged_autoprobe has been added. This
value is used as the drivers_autoprobe setting of the VFs when they are
being managed by an external entity such as userspace or device firmware
instead of being managed by the kernel.
One side effect of this change is that the sriov_drivers_autoprobe and
sriov_unmanaged_autoprobe will only apply their updates when SR-IOV is
disabled. Attempts to update them when SR-IOV is in use will only update
the local value and will not update sriov->autoprobe.
Signed-off-by: Alexander Duyck
---
Documentation/ABI/testing/sysfs-bus-pci | 17 ++
drivers/pci/iov.c | 37 +++
drivers/pci/pci-driver.c|2 +-
drivers/pci/pci-sysfs.c | 29
drivers/pci/pci.h |4 +++
include/linux/pci.h |1 +
6 files changed, 88 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-pci
b/Documentation/ABI/testing/sysfs-bus-pci
index 44d4b2be92fd..ff0b6c19cb1a 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -323,3 +323,20 @@ Description:
This is similar to /sys/bus/pci/drivers_autoprobe, but
affects only the VFs associated with a specific PF.
+
+What: /sys/bus/pci/devices/.../sriov_unmanaged_autoprobe
+Date: March 2018
+Contact: Alexander Duyck
+Description:
+ This file is associated with the PF of a device that
+ supports SR-IOV. It determines whether newly-enabled VFs
+ are immediately bound to a driver when the PF driver does
+ not manage the VFs itself. It initially contains 0, which
+ means the kernel will not automatically bind VFs to a driver.
+ If an application writes 1 to the file before enabling VFs,
+ the kernel will bind VFs to a compatible driver immediately
+ after they are enabled.
+
+ This overrides /sys/bus/pci/devices/.../sriov_drivers_autoprobe
+ when a PF driver is not present to manage a device, or the PF
+ driver does not provide functionality to support SR-IOV.
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 677924ae0350..3dcec1fa86bd 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -446,6 +446,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
pci_read_config_word(dev, pos + PCI_SRIOV_VF_DID, &iov->vf_device);
iov->pgsz = pgsz;
iov->self = dev;
+ iov->autoprobe = true;
iov->drivers_autoprobe = true;
pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
@@ -683,6 +684,9 @@ int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
if (!dev->is_physfn)
return -ENOSYS;
+ /* Update autoprobe setting to reflect managed device */
+ dev->sriov->autoprobe = dev->sriov->drivers_autoprobe;
+
return sriov_enable(dev, nr_virtfn);
}
EXPORT_SYMBOL_GPL(pci_enable_sriov);
@@ -807,3 +811,36 @@ int pci_sriov_get_totalvfs(struct pci_dev *dev)
return dev->sriov->total_VFs;
}
EXPORT_SYMBOL_GPL(pci_sriov_get_totalvfs);
+
+/**
+ * pci_sriov_configure_unmanaged - helper to configure unmanaged SR-IOV
+ * @dev: the PCI device
+ * @nr_virtfn: number of virtual functions to enable, 0 to disable
+ *
+ * Used to provide generic enable/disable SR-IOV option for devices
+ * that do not manage the VFs generated by their driver, or have no
+ * driver present.
+ */
+int pci_sriov_configure_unmanaged(struct pci_dev *dev, int nr_virtfn)
+{
+ int err;
+
+ might_sleep();
+
+ if (!dev->is_physfn)
+ return -ENODEV;
+
+ if (!nr_virtfn) {
+ sriov_disable(dev);
+
+ return 0;
+ }
+
+ /* Update autoprobe setting to reflect unmanaged device */
+ dev->sriov->autoprobe = dev->sriov->unmanaged_autoprobe;
+
+ err = sriov_enable(dev, nr_virtfn);
+
+ return err ? err : nr_virtfn;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_configure_unmanaged);
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 3bed6beda051..2cc68dff6130 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -398,7 +398,7 @@ void __weak pcibios_free_irq(struct pci_dev *dev)
#ifdef CONFIG_PCI_IOV
static inline bool pci_device_can_probe(struct pci_dev *pdev)
{
- return (!pdev->is_virtfn || pdev->ph
