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powerpc/powernv: Fix IOMMU table for VFIO dev
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On PHB3, PCI devices can bypass IOMMU for DMA access. If we pass
through one PCI device, whose hose driver ever enable the bypass
mode, pdev->dev.archdata.dma_data.iommu_table_base isn't IOMMU
table. However, EEH needs access the IOMMU table when the device
is owned by guest.

The patch fixes pdev->dev.archdata.dma_data.iommu_table when
passing through the device to guest in pnv_pci_ioda2_set_bypass().

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Gavin Shan authored and Benjamin Herrenschmidt committed Aug 5, 2014
1 parent 9e5c6e5 commit dff4a39
Showing 1 changed file with 21 additions and 9 deletions.
30 changes: 21 additions & 9 deletions arch/powerpc/platforms/powernv/pci-ioda.c
Original file line number Diff line number Diff line change
Expand Up @@ -495,14 +495,22 @@ static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
return 0;
}

static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus)
static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
struct pci_bus *bus,
bool add_to_iommu_group)
{
struct pci_dev *dev;

list_for_each_entry(dev, &bus->devices, bus_list) {
set_iommu_table_base_and_group(&dev->dev, &pe->tce32_table);
if (add_to_iommu_group)
set_iommu_table_base_and_group(&dev->dev,
&pe->tce32_table);
else
set_iommu_table_base(&dev->dev, &pe->tce32_table);

if (dev->subordinate)
pnv_ioda_setup_bus_dma(pe, dev->subordinate);
pnv_ioda_setup_bus_dma(pe, dev->subordinate,
add_to_iommu_group);
}
}

Expand Down Expand Up @@ -680,7 +688,7 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
if (pe->pdev)
set_iommu_table_base_and_group(&pe->pdev->dev, tbl);
else
pnv_ioda_setup_bus_dma(pe, pe->pbus);
pnv_ioda_setup_bus_dma(pe, pe->pbus, true);

return;
fail:
Expand Down Expand Up @@ -716,11 +724,15 @@ static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable)
0);

/*
* We might want to reset the DMA ops of all devices on
* this PE. However in theory, that shouldn't be necessary
* as this is used for VFIO/KVM pass-through and the device
* hasn't yet been returned to its kernel driver
* EEH needs the mapping between IOMMU table and group
* of those VFIO/KVM pass-through devices. We can postpone
* resetting DMA ops until the DMA mask is configured in
* host side.
*/
if (pe->pdev)
set_iommu_table_base(&pe->pdev->dev, tbl);
else
pnv_ioda_setup_bus_dma(pe, pe->pbus, false);
}
if (rc)
pe_err(pe, "OPAL error %lld configuring bypass window\n", rc);
Expand Down Expand Up @@ -809,7 +821,7 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
if (pe->pdev)
set_iommu_table_base_and_group(&pe->pdev->dev, tbl);
else
pnv_ioda_setup_bus_dma(pe, pe->pbus);
pnv_ioda_setup_bus_dma(pe, pe->pbus, true);

/* Also create a bypass window */
pnv_pci_ioda2_setup_bypass_pe(phb, pe);
Expand Down

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