Re: [PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
On Wed, Oct 07, 2015 at 03:21:36PM -0500, Ben Shelton wrote: > Hi Bjorn, > > On Wed, Oct 07, 2015 at 02:29:40PM -0500, Bjorn Helgaas wrote: > > Hi Ben, > > > > On Fri, Sep 11, 2015 at 04:55:00PM -0500, Ben Shelton wrote: > > > For some SR-IOV devices, the number of available virtual functions > > > increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved > > > off before the ARI control bit is enabled. This causes an issue when VFs > > > are enabled. > > > > > > At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain > > > the number of available VFs for the device. sriov_enable() does a sanity > > > check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the > > > saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF > > > and SRIOV_NUM_VF has increased after enabling the ARI bit, the check > > > fails, > > > and the VFs cannot be enabled. > > > > > > To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. > > > > > > Signed-off-by: Ben Shelton > > > --- > > > drivers/pci/iov.c | 9 - > > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > > > index ee0ebff..88b1959 100644 > > > --- a/drivers/pci/iov.c > > > +++ b/drivers/pci/iov.c > > > @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) > > > struct pci_sriov *iov; > > > struct resource *res; > > > struct pci_dev *pdev; > > > + bool total_needs_reread = false; > > > > > > if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && > > > pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) > > > @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) > > > goto found; > > > > > > pdev = NULL; > > > - if (pci_ari_enabled(dev->bus)) > > > + if (pci_ari_enabled(dev->bus)) { > > > ctrl |= PCI_SRIOV_CTRL_ARI; > > > + total_needs_reread = true; > > > + } > > > > > > found: > > > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > > > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); > > > + > > > + if (total_needs_reread) > > > + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); > > > > Can we just *move* the PCI_SRIOV_TOTAL_VF read from its original > > location and do it unconditionally here? I don't think we use "total" > > for anything in the interim, and it'd be nice if we could do this > > without the "total_needs_reread" flag. > > The only thing we do with 'total' is return early if it's read as 0 > (i.e. for a device that does not support any VFs). If we just move the > read to here, a PCI device with no VFs would have its PCI_SRIOV_CTRL > config word written before PCI_SRIOV_TOTAL_VF is read as 0 and > sriov_init() returns. The reread preserves the original behavior. > > If the change in behavior is OK, I'll make the change and submit a v2. I think that's OK. We do return some other errors after modifying PCI_SRIOV_CTRL, so I don't know that this would be any worse. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
Hi Bjorn, On Wed, Oct 07, 2015 at 02:29:40PM -0500, Bjorn Helgaas wrote: > Hi Ben, > > On Fri, Sep 11, 2015 at 04:55:00PM -0500, Ben Shelton wrote: > > For some SR-IOV devices, the number of available virtual functions > > increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved > > off before the ARI control bit is enabled. This causes an issue when VFs > > are enabled. > > > > At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain > > the number of available VFs for the device. sriov_enable() does a sanity > > check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the > > saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF > > and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, > > and the VFs cannot be enabled. > > > > To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. > > > > Signed-off-by: Ben Shelton > > --- > > drivers/pci/iov.c | 9 - > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > > index ee0ebff..88b1959 100644 > > --- a/drivers/pci/iov.c > > +++ b/drivers/pci/iov.c > > @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) > > struct pci_sriov *iov; > > struct resource *res; > > struct pci_dev *pdev; > > + bool total_needs_reread = false; > > > > if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && > > pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) > > @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) > > goto found; > > > > pdev = NULL; > > - if (pci_ari_enabled(dev->bus)) > > + if (pci_ari_enabled(dev->bus)) { > > ctrl |= PCI_SRIOV_CTRL_ARI; > > + total_needs_reread = true; > > + } > > > > found: > > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); > > + > > + if (total_needs_reread) > > + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); > > Can we just *move* the PCI_SRIOV_TOTAL_VF read from its original > location and do it unconditionally here? I don't think we use "total" > for anything in the interim, and it'd be nice if we could do this > without the "total_needs_reread" flag. The only thing we do with 'total' is return early if it's read as 0 (i.e. for a device that does not support any VFs). If we just move the read to here, a PCI device with no VFs would have its PCI_SRIOV_CTRL config word written before PCI_SRIOV_TOTAL_VF is read as 0 and sriov_init() returns. The reread preserves the original behavior. If the change in behavior is OK, I'll make the change and submit a v2. Thanks, Ben > > > pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, ); > > pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, ); > > if (!offset || (total > 1 && !stride)) > > -- > > 1.9.5 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majord...@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
Hi Ben, On Fri, Sep 11, 2015 at 04:55:00PM -0500, Ben Shelton wrote: > For some SR-IOV devices, the number of available virtual functions > increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved > off before the ARI control bit is enabled. This causes an issue when VFs > are enabled. > > At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain > the number of available VFs for the device. sriov_enable() does a sanity > check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the > saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF > and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, > and the VFs cannot be enabled. > > To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. > > Signed-off-by: Ben Shelton > --- > drivers/pci/iov.c | 9 - > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > index ee0ebff..88b1959 100644 > --- a/drivers/pci/iov.c > +++ b/drivers/pci/iov.c > @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) > struct pci_sriov *iov; > struct resource *res; > struct pci_dev *pdev; > + bool total_needs_reread = false; > > if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && > pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) > @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) > goto found; > > pdev = NULL; > - if (pci_ari_enabled(dev->bus)) > + if (pci_ari_enabled(dev->bus)) { > ctrl |= PCI_SRIOV_CTRL_ARI; > + total_needs_reread = true; > + } > > found: > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); > + > + if (total_needs_reread) > + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); Can we just *move* the PCI_SRIOV_TOTAL_VF read from its original location and do it unconditionally here? I don't think we use "total" for anything in the interim, and it'd be nice if we could do this without the "total_needs_reread" flag. > pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, ); > pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, ); > if (!offset || (total > 1 && !stride)) > -- > 1.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
Hi Bjorn, On Wed, Oct 07, 2015 at 02:29:40PM -0500, Bjorn Helgaas wrote: > Hi Ben, > > On Fri, Sep 11, 2015 at 04:55:00PM -0500, Ben Shelton wrote: > > For some SR-IOV devices, the number of available virtual functions > > increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved > > off before the ARI control bit is enabled. This causes an issue when VFs > > are enabled. > > > > At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain > > the number of available VFs for the device. sriov_enable() does a sanity > > check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the > > saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF > > and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, > > and the VFs cannot be enabled. > > > > To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. > > > > Signed-off-by: Ben Shelton> > --- > > drivers/pci/iov.c | 9 - > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > > index ee0ebff..88b1959 100644 > > --- a/drivers/pci/iov.c > > +++ b/drivers/pci/iov.c > > @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) > > struct pci_sriov *iov; > > struct resource *res; > > struct pci_dev *pdev; > > + bool total_needs_reread = false; > > > > if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && > > pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) > > @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) > > goto found; > > > > pdev = NULL; > > - if (pci_ari_enabled(dev->bus)) > > + if (pci_ari_enabled(dev->bus)) { > > ctrl |= PCI_SRIOV_CTRL_ARI; > > + total_needs_reread = true; > > + } > > > > found: > > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); > > + > > + if (total_needs_reread) > > + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); > > Can we just *move* the PCI_SRIOV_TOTAL_VF read from its original > location and do it unconditionally here? I don't think we use "total" > for anything in the interim, and it'd be nice if we could do this > without the "total_needs_reread" flag. The only thing we do with 'total' is return early if it's read as 0 (i.e. for a device that does not support any VFs). If we just move the read to here, a PCI device with no VFs would have its PCI_SRIOV_CTRL config word written before PCI_SRIOV_TOTAL_VF is read as 0 and sriov_init() returns. The reread preserves the original behavior. If the change in behavior is OK, I'll make the change and submit a v2. Thanks, Ben > > > pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, ); > > pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, ); > > if (!offset || (total > 1 && !stride)) > > -- > > 1.9.5 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majord...@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
On Wed, Oct 07, 2015 at 03:21:36PM -0500, Ben Shelton wrote: > Hi Bjorn, > > On Wed, Oct 07, 2015 at 02:29:40PM -0500, Bjorn Helgaas wrote: > > Hi Ben, > > > > On Fri, Sep 11, 2015 at 04:55:00PM -0500, Ben Shelton wrote: > > > For some SR-IOV devices, the number of available virtual functions > > > increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved > > > off before the ARI control bit is enabled. This causes an issue when VFs > > > are enabled. > > > > > > At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain > > > the number of available VFs for the device. sriov_enable() does a sanity > > > check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the > > > saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF > > > and SRIOV_NUM_VF has increased after enabling the ARI bit, the check > > > fails, > > > and the VFs cannot be enabled. > > > > > > To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. > > > > > > Signed-off-by: Ben Shelton> > > --- > > > drivers/pci/iov.c | 9 - > > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > > > index ee0ebff..88b1959 100644 > > > --- a/drivers/pci/iov.c > > > +++ b/drivers/pci/iov.c > > > @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) > > > struct pci_sriov *iov; > > > struct resource *res; > > > struct pci_dev *pdev; > > > + bool total_needs_reread = false; > > > > > > if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && > > > pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) > > > @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) > > > goto found; > > > > > > pdev = NULL; > > > - if (pci_ari_enabled(dev->bus)) > > > + if (pci_ari_enabled(dev->bus)) { > > > ctrl |= PCI_SRIOV_CTRL_ARI; > > > + total_needs_reread = true; > > > + } > > > > > > found: > > > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > > > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); > > > + > > > + if (total_needs_reread) > > > + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); > > > > Can we just *move* the PCI_SRIOV_TOTAL_VF read from its original > > location and do it unconditionally here? I don't think we use "total" > > for anything in the interim, and it'd be nice if we could do this > > without the "total_needs_reread" flag. > > The only thing we do with 'total' is return early if it's read as 0 > (i.e. for a device that does not support any VFs). If we just move the > read to here, a PCI device with no VFs would have its PCI_SRIOV_CTRL > config word written before PCI_SRIOV_TOTAL_VF is read as 0 and > sriov_init() returns. The reread preserves the original behavior. > > If the change in behavior is OK, I'll make the change and submit a v2. I think that's OK. We do return some other errors after modifying PCI_SRIOV_CTRL, so I don't know that this would be any worse. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
Hi Ben, On Fri, Sep 11, 2015 at 04:55:00PM -0500, Ben Shelton wrote: > For some SR-IOV devices, the number of available virtual functions > increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved > off before the ARI control bit is enabled. This causes an issue when VFs > are enabled. > > At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain > the number of available VFs for the device. sriov_enable() does a sanity > check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the > saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF > and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, > and the VFs cannot be enabled. > > To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. > > Signed-off-by: Ben Shelton> --- > drivers/pci/iov.c | 9 - > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > index ee0ebff..88b1959 100644 > --- a/drivers/pci/iov.c > +++ b/drivers/pci/iov.c > @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) > struct pci_sriov *iov; > struct resource *res; > struct pci_dev *pdev; > + bool total_needs_reread = false; > > if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && > pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) > @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) > goto found; > > pdev = NULL; > - if (pci_ari_enabled(dev->bus)) > + if (pci_ari_enabled(dev->bus)) { > ctrl |= PCI_SRIOV_CTRL_ARI; > + total_needs_reread = true; > + } > > found: > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); > + > + if (total_needs_reread) > + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); Can we just *move* the PCI_SRIOV_TOTAL_VF read from its original location and do it unconditionally here? I don't think we use "total" for anything in the interim, and it'd be nice if we could do this without the "total_needs_reread" flag. > pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, ); > pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, ); > if (!offset || (total > 1 && !stride)) > -- > 1.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
For some SR-IOV devices, the number of available virtual functions increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved off before the ARI control bit is enabled. This causes an issue when VFs are enabled. At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain the number of available VFs for the device. sriov_enable() does a sanity check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, and the VFs cannot be enabled. To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. Signed-off-by: Ben Shelton --- drivers/pci/iov.c | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee0ebff..88b1959 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) struct pci_sriov *iov; struct resource *res; struct pci_dev *pdev; + bool total_needs_reread = false; if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) goto found; pdev = NULL; - if (pci_ari_enabled(dev->bus)) + if (pci_ari_enabled(dev->bus)) { ctrl |= PCI_SRIOV_CTRL_ARI; + total_needs_reread = true; + } found: pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); + + if (total_needs_reread) + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); + pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, ); pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, ); if (!offset || (total > 1 && !stride)) -- 1.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] PCI: IOV: reread SRIOV_NUM_VF after enabling ARI
For some SR-IOV devices, the number of available virtual functions increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved off before the ARI control bit is enabled. This causes an issue when VFs are enabled. At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain the number of available VFs for the device. sriov_enable() does a sanity check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails, and the VFs cannot be enabled. To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF. Signed-off-by: Ben Shelton--- drivers/pci/iov.c | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ee0ebff..88b1959 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos) struct pci_sriov *iov; struct resource *res; struct pci_dev *pdev; + bool total_needs_reread = false; if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END && pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) @@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos) goto found; pdev = NULL; - if (pci_ari_enabled(dev->bus)) + if (pci_ari_enabled(dev->bus)) { ctrl |= PCI_SRIOV_CTRL_ARI; + total_needs_reread = true; + } found: pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0); + + if (total_needs_reread) + pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, ); + pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, ); pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, ); if (!offset || (total > 1 && !stride)) -- 1.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/