Mailing List Archive

At least certain Marvell SATA controllers are known to issue bus master
requests with a non-zero function as origin, despite themselves being
single function devices.

--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -698,6 +698,16 @@ Defaults to booting secondary processors

Default: `on`

+### pci-phantom
+> `=[<seg>:]<bus>:<device>,<stride>`
+
+Mark a group of PCI devices as using phantom functions without actually
+advertising so, so the IOMMU can create translation contexts for them.
+
+All numbers specified must be hexadecimal ones.
+
+This option can be specified more than once (up to 8 times at present).
+
### ple\_gap
> `= <integer>`

--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -121,6 +121,49 @@ const unsigned long *pci_get_ro_map(u16
return pseg ? pseg->ro_map : NULL;
}

+static struct phantom_dev {
+ u16 seg;
+ u8 bus, slot, stride;
+} phantom_devs[8];
+static unsigned int nr_phantom_devs;
+
+static void __init parse_phantom_dev(char *str) {
+ const char *s = str;
+ struct phantom_dev phantom;
+
+ if ( !s || !*s || nr_phantom_devs >= ARRAY_SIZE(phantom_devs) )
+ return;
+
+ phantom.seg = simple_strtol(s, &s, 16);
+ if ( *s != ':' )
+ return;
+
+ phantom.bus = simple_strtol(s + 1, &s, 16);
+ if ( *s == ',' )
+ {
+ phantom.slot = phantom.bus;
+ phantom.bus = phantom.seg;
+ phantom.seg = 0;
+ }
+ else if ( *s == ':' )
+ phantom.slot = simple_strtol(s + 1, &s, 16);
+ else
+ return;
+
+ if ( *s != ',' )
+ return;
+ switch ( phantom.stride = simple_strtol(s + 1, &s, 0) )
+ {
+ case 1: case 2: case 4:
+ if ( *s )
+ default:
+ return;
+ }
+
+ phantom_devs[nr_phantom_devs++] = phantom;
+}
+custom_param("pci-phantom", parse_phantom_dev);
+
static struct pci_dev *alloc_pdev(struct pci_seg *pseg, u8 bus, u8 devfn)
{
struct pci_dev *pdev;
@@ -181,6 +224,20 @@ static struct pci_dev *alloc_pdev(struct
if ( PCI_FUNC(devfn) >= pdev->phantom_stride )
pdev->phantom_stride = 0;
}
+ else
+ {
+ unsigned int i;
+
+ for ( i = 0; i < nr_phantom_devs; ++i )
+ if ( phantom_devs[i].seg == pseg->nr &&
+ phantom_devs[i].bus == bus &&
+ phantom_devs[i].slot == PCI_SLOT(devfn) &&
+ phantom_devs[i].stride > PCI_FUNC(devfn) )
+ {
+ pdev->phantom_stride = phantom_devs[i].stride;
+ break;
+ }
+ }
break;

case DEV_TYPE_PCI: