* [PATCH 1/2] powerpc/powernv: Fix IOMMU table for VFIO dev
2014-07-15 7:00 [PATCH 0/2] Bug fix for VFIO EEH Gavin Shan
@ 2014-07-15 7:00 ` Gavin Shan
2014-07-15 7:00 ` [PATCH 2/2] powerpc/eeh: Fetch IOMMU table in reliable way Gavin Shan
1 sibling, 0 replies; 3+ messages in thread
From: Gavin Shan @ 2014-07-15 7:00 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Gavin Shan
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>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index de19ede..93fd815 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -494,14 +494,22 @@ 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);
}
}
@@ -677,7 +685,7 @@ 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:
@@ -713,11 +721,15 @@ 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);
@@ -805,7 +817,7 @@ 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);
--
1.8.3.2
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] powerpc/eeh: Fetch IOMMU table in reliable way
2014-07-15 7:00 [PATCH 0/2] Bug fix for VFIO EEH Gavin Shan
2014-07-15 7:00 ` [PATCH 1/2] powerpc/powernv: Fix IOMMU table for VFIO dev Gavin Shan
@ 2014-07-15 7:00 ` Gavin Shan
1 sibling, 0 replies; 3+ messages in thread
From: Gavin Shan @ 2014-07-15 7:00 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Gavin Shan
Function eeh_iommu_group_to_pe() iterates each PCI device to check
the binding IOMMU group with get_iommu_table_base(), which possibly
fetches pdev->dev.archdata.dma_data.dma_offset. It's (0x1 << 59)
for "bypass" cases.
The patch fixes the issue by iterating devices hooked to the IOMMU
group and fetch IOMMU table there.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
arch/powerpc/kernel/eeh.c | 33 ++++++++++++++++++++++-----------
1 file changed, 22 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 18c40fd..4de2103 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -27,6 +27,7 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/pci.h>
+#include <linux/iommu.h>
#include <linux/proc_fs.h>
#include <linux/rbtree.h>
#include <linux/reboot.h>
@@ -1178,6 +1179,24 @@ out:
}
EXPORT_SYMBOL(eeh_dev_release);
+static int dev_has_iommu_table(struct device *dev, void *data)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct pci_dev **ppdev = data;
+ struct iommu_table *tbl;
+
+ if (!dev)
+ return 0;
+
+ tbl = get_iommu_table_base(dev);
+ if (tbl && tbl->it_group) {
+ *ppdev = pdev;
+ return 1;
+ }
+
+ return 0;
+}
+
/**
* eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE
* @group: IOMMU group
@@ -1186,24 +1205,16 @@ EXPORT_SYMBOL(eeh_dev_release);
*/
struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group)
{
- struct iommu_table *tbl;
struct pci_dev *pdev = NULL;
struct eeh_dev *edev;
- bool found = false;
+ int ret;
/* No IOMMU group ? */
if (!group)
return NULL;
- /* No PCI device ? */
- for_each_pci_dev(pdev) {
- tbl = get_iommu_table_base(&pdev->dev);
- if (tbl && tbl->it_group == group) {
- found = true;
- break;
- }
- }
- if (!found)
+ ret = iommu_group_for_each_dev(group, &pdev, dev_has_iommu_table);
+ if (!ret || !pdev)
return NULL;
/* No EEH device or PE ? */
--
1.8.3.2
^ permalink raw reply related [flat|nested] 3+ messages in thread