On Wed, 14 Jun 2017 15:23:01 -0700 Jacob Pan <[email protected]> wrote:
> Currently, when device DMA faults are detected by IOMMU the fault > reasons are printed but the offending device is not notified. > This patch allows device drivers to be optionally notified for fault > conditions when device specific handling is needed for more subtle > processing, e.g. request with PASID transactions. > > Signed-off-by: Jacob Pan <[email protected]> > Signed-off-by: Ashok Raj <[email protected]> > --- > drivers/iommu/dmar.c | 37 ++++++++++++++++++++++++++++++++++++- > 1 file changed, 36 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c > index cbf7763..2c0b80d464 100644 > --- a/drivers/iommu/dmar.c > +++ b/drivers/iommu/dmar.c > @@ -1587,11 +1587,43 @@ void dmar_msi_read(int irq, struct msi_msg *msg) > raw_spin_unlock_irqrestore(&iommu->register_lock, flag); > } > > +static int dmar_unrecov_fault_notify(u8 fault_reason, u16 source_id, > + unsigned long long addr) > +{ > + int ret; > + struct pci_dev *pdev; > + struct iommu_fault_event *event; > + > + pdev = pci_get_bus_and_slot(source_id >> 8, source_id & 0xFF); > + if (!pdev) > + return -ENODEV; > + pr_debug("Notify PCI device fault [%02x:%02x.%d]\n", > + source_id >> 8, PCI_SLOT(source_id & 0xff), > + PCI_FUNC(source_id & 0xff)); > + event = kzalloc(sizeof(*event) + sizeof(fault_reason), GFP_KERNEL); > + if (!event) > + return -ENOMEM; Leaks pdev reference. > + > + pci_dev_get(pdev); > + event->dev = &pdev->dev; > + event->buf[0] = fault_reason; > + event->addr = addr; > + event->length = sizeof(fault_reason); > + event->flags = IOMMU_FAULT_UNRECOV; > + ret = iommu_fault_notifier_call_chain(event); > + > + pci_dev_put(pdev); > + kfree(event); > + > + return ret; > +} > + > static int dmar_fault_do_one(struct intel_iommu *iommu, int type, > u8 fault_reason, u16 source_id, unsigned long long addr) > { > const char *reason; > int fault_type; > + int ret = 0; > > reason = dmar_get_fault_reason(fault_reason, &fault_type); > > @@ -1600,11 +1632,14 @@ static int dmar_fault_do_one(struct intel_iommu > *iommu, int type, > source_id >> 8, PCI_SLOT(source_id & 0xFF), > PCI_FUNC(source_id & 0xFF), addr >> 48, > fault_reason, reason); > - else > + else { > pr_err("[%s] Request device [%02x:%02x.%d] fault addr %llx > [fault reason %02d] %s\n", > type ? "DMA Read" : "DMA Write", > source_id >> 8, PCI_SLOT(source_id & 0xFF), > PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason); > + ret = dmar_unrecov_fault_notify(fault_reason, source_id, addr); For what purpose are we recording this return code? > + } > + > return 0; > } >
