First of all there were three places potentially de-referencing NULL
(two after an allocation failure, and one after a failed lookup).
Second, if ATS_ENABLE was already set, the device would not have got
added to the ats_devices list, potentially resulting in
dev_invalidate_iotlb() doing an incomplete job.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- a/xen/drivers/passthrough/vtd/x86/ats.c
+++ b/xen/drivers/passthrough/vtd/x86/ats.c
@@ -93,6 +93,9 @@ int ats_device(int seg, int bus, int dev
return 0;
pdev = pci_get_pdev(bus, devfn);
+ if ( !pdev )
+ return 0;
+
drhd = acpi_find_matched_drhd_unit(pdev);
if ( !drhd )
return 0;
@@ -110,6 +113,8 @@ int ats_device(int seg, int bus, int dev
if ( pos && (ats_drhd == NULL) )
{
new_drhd = xmalloc(struct acpi_drhd_unit);
+ if ( !new_drhd )
+ return 0;
memcpy(new_drhd, drhd, sizeof(struct acpi_drhd_unit));
list_add_tail(&new_drhd->list, &ats_dev_drhd_units);
}
@@ -118,9 +123,8 @@ int ats_device(int seg, int bus, int dev
int enable_ats_device(int seg, int bus, int devfn)
{
- struct pci_ats_dev *pdev;
+ struct pci_ats_dev *pdev = NULL;
u32 value;
- u16 queue_depth;
int pos;
if ( !acpi_find_matched_atsr_unit(bus, devfn) )
@@ -144,26 +148,43 @@ int enable_ats_device(int seg, int bus,
/* BUGBUG: add back seg when multi-seg platform support is enabled */
value = pci_conf_read16(bus, PCI_SLOT(devfn),
- PCI_FUNC(devfn), pos + ATS_REG_CAP);
- queue_depth = value & ATS_QUEUE_DEPTH_MASK;
-
- value = pci_conf_read16(bus, PCI_SLOT(devfn),
PCI_FUNC(devfn), pos + ATS_REG_CTL);
if ( value & ATS_ENABLE )
- return 0;
+ {
+ list_for_each_entry ( pdev, &ats_devices, list )
+ {
+ if ( pdev->bus == bus && pdev->devfn == devfn )
+ {
+ pos = 0;
+ break;
+ }
+ }
+ }
+ if ( pos )
+ pdev = xmalloc(struct pci_ats_dev);
+ if ( !pdev )
+ return -ENOMEM;
- value |= ATS_ENABLE;
- pci_conf_write16(bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
- pos + ATS_REG_CTL, value);
+ if ( !(value & ATS_ENABLE) )
+ {
+ value |= ATS_ENABLE;
+ pci_conf_write16(bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
+ pos + ATS_REG_CTL, value);
+ }
+
+ if ( pos )
+ {
+ pdev->bus = bus;
+ pdev->devfn = devfn;
+ value = pci_conf_read16(bus, PCI_SLOT(devfn),
+ PCI_FUNC(devfn), pos + ATS_REG_CAP);
+ pdev->ats_queue_depth = value & ATS_QUEUE_DEPTH_MASK;
+ list_add(&pdev->list, &ats_devices);
+ }
- pdev = xmalloc(struct pci_ats_dev);
- pdev->bus = bus;
- pdev->devfn = devfn;
- pdev->ats_queue_depth = queue_depth;
- list_add(&(pdev->list), &ats_devices);
if ( iommu_verbose )
- dprintk(XENLOG_INFO VTDPREFIX, "%x:%x.%x: ATS is enabled\n",
- bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+ dprintk(XENLOG_INFO VTDPREFIX, "%x:%x.%x: ATS %s enabled\n",
+ bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos ? "is" :
"was");
return pos;
}
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