| Message ID | 1539650888-3792-2-git-send-email-jonathan.derrick@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | VMD fixes for 4.20 | expand |
On Mon, Oct 15, 2018 at 05:48:07PM -0700, Jon Derrick wrote: > The VMD removal path calls pci_stop_root_bus, which tears down the pcie > tree, including detaching all of the attached drivers. During driver > detachment, devices may use pci_release_region to release resources. > This path relies on the resource being accessible in resource tree. > > By detaching the child domain from the parent resource domain prior to > stopping the bus, we are preventing the list traversal from finding the > resource to be freed. If we instead detach the resource after stopping > the bus, we will have properly freed the resource and detaching is > simply accounting at that point. > > Without this order, the resource is never freed and is orphaned on VMD > removal, leading to warning: > [ 181.940162] Trying to free nonexistent resource <e5a10000-e5a13fff> > > Fixes 2c2c5c5cd213aea38c850bb6edc9b7f77f29802f: > "x86/PCI: VMD: Attach VMD resources to parent domain's resource tree" > Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> Looks good. Reviewed-by: Keith Busch <keith.busch@intel.com> > --- > drivers/pci/controller/vmd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index fd2dbd7..46ed80f 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -813,12 +813,12 @@ static void vmd_remove(struct pci_dev *dev) > { > struct vmd_dev *vmd = pci_get_drvdata(dev); > > - vmd_detach_resources(vmd); > sysfs_remove_link(&vmd->dev->dev.kobj, "domain"); > pci_stop_root_bus(vmd->bus); > pci_remove_root_bus(vmd->bus); > vmd_cleanup_srcu(vmd); > vmd_teardown_dma_ops(vmd); > + vmd_detach_resources(vmd); > irq_domain_remove(vmd->irq_domain); > } > > -- > 1.8.3.1 >
On Mon, Oct 15, 2018 at 06:48:07PM -0600, Jon Derrick wrote: > The VMD removal path calls pci_stop_root_bus, which tears down the pcie > tree, including detaching all of the attached drivers. During driver > detachment, devices may use pci_release_region to release resources. > This path relies on the resource being accessible in resource tree. > > By detaching the child domain from the parent resource domain prior to > stopping the bus, we are preventing the list traversal from finding the > resource to be freed. If we instead detach the resource after stopping > the bus, we will have properly freed the resource and detaching is > simply accounting at that point. > > Without this order, the resource is never freed and is orphaned on VMD > removal, leading to warning: > [ 181.940162] Trying to free nonexistent resource <e5a10000-e5a13fff> > > Fixes 2c2c5c5cd213aea38c850bb6edc9b7f77f29802f: > "x86/PCI: VMD: Attach VMD resources to parent domain's resource tree" > Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> > --- > drivers/pci/controller/vmd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) I have applied this patch to pci/vmd for v4.20, thanks. Lorenzo > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index fd2dbd7..46ed80f 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -813,12 +813,12 @@ static void vmd_remove(struct pci_dev *dev) > { > struct vmd_dev *vmd = pci_get_drvdata(dev); > > - vmd_detach_resources(vmd); > sysfs_remove_link(&vmd->dev->dev.kobj, "domain"); > pci_stop_root_bus(vmd->bus); > pci_remove_root_bus(vmd->bus); > vmd_cleanup_srcu(vmd); > vmd_teardown_dma_ops(vmd); > + vmd_detach_resources(vmd); > irq_domain_remove(vmd->irq_domain); > } > > -- > 1.8.3.1 >
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index fd2dbd7..46ed80f 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -813,12 +813,12 @@ static void vmd_remove(struct pci_dev *dev) { struct vmd_dev *vmd = pci_get_drvdata(dev); - vmd_detach_resources(vmd); sysfs_remove_link(&vmd->dev->dev.kobj, "domain"); pci_stop_root_bus(vmd->bus); pci_remove_root_bus(vmd->bus); vmd_cleanup_srcu(vmd); vmd_teardown_dma_ops(vmd); + vmd_detach_resources(vmd); irq_domain_remove(vmd->irq_domain); }
The VMD removal path calls pci_stop_root_bus, which tears down the pcie tree, including detaching all of the attached drivers. During driver detachment, devices may use pci_release_region to release resources. This path relies on the resource being accessible in resource tree. By detaching the child domain from the parent resource domain prior to stopping the bus, we are preventing the list traversal from finding the resource to be freed. If we instead detach the resource after stopping the bus, we will have properly freed the resource and detaching is simply accounting at that point. Without this order, the resource is never freed and is orphaned on VMD removal, leading to warning: [ 181.940162] Trying to free nonexistent resource <e5a10000-e5a13fff> Fixes 2c2c5c5cd213aea38c850bb6edc9b7f77f29802f: "x86/PCI: VMD: Attach VMD resources to parent domain's resource tree" Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> --- drivers/pci/controller/vmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)