On 2015/6/11 18:25, Tian, Kevin wrote:
From: Chen, Tiejun
Sent: Thursday, June 11, 2015 9:15 AM
Currently we're intending to cover this kind of devices
we're -> we're not?
I mean currently we want to handle this shared case *simply* so I think
its still "we're", right?
with shared RMRR simply since the case of shared RMRR is
a rare case according to our previous experiences. But
late we can group these devices which shared rmrr, and
then allow all devices within a group to be assigned to
same domain.
Signed-off-by: Tiejun Chen <tiejun.c...@intel.com>
Acked-by: Kevin Tian <kevin.t...@intel.com> except one text
comment.
---
xen/drivers/passthrough/vtd/iommu.c | 30
+++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)
diff --git a/xen/drivers/passthrough/vtd/iommu.c
b/xen/drivers/passthrough/vtd/iommu.c
index d3233b8..f220081 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2277,13 +2277,37 @@ static int intel_iommu_assign_device(
if ( list_empty(&acpi_drhd_units) )
return -ENODEV;
+ seg = pdev->seg;
+ bus = pdev->bus;
+ /*
+ * In rare cases one given rmrr is shared by multiple devices but
+ * obviously this would put the security of a system at risk. So
+ * we should prevent from this sort of device assignment.
+ *
+ * TODO: actually we can group these devices which shared rmrr, and
+ * then allow all devices within a group to be assigned to same domain.
TODO: in the future we can introduce group device assignment
interface to make sure devices sharing RMRR are assigned to the
same domain together.
Thank you to rephrase this.
Tiejun
+ */
+ for_each_rmrr_device( rmrr, bdf, i )
+ {
+ if ( rmrr->segment == seg &&
+ PCI_BUS(bdf) == bus &&
+ PCI_DEVFN2(bdf) == devfn )
+ {
+ if ( rmrr->scope.devices_cnt > 1 )
+ {
+ ret = -EPERM;
+ printk(XENLOG_G_ERR VTDPREFIX
+ " cannot assign this device with shared RMRR for Dom%d
(%d)\n",
+ d->domain_id, ret);
+ return ret;
+ }
+ }
+ }
+
ret = reassign_device_ownership(hardware_domain, d, devfn, pdev);
if ( ret )
return ret;
- seg = pdev->seg;
- bus = pdev->bus;
-
/* Setup rmrr identity mapping */
for_each_rmrr_device( rmrr, bdf, i )
{
--
1.9.1
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