This patch is being submitted to handle the case where a pci device is
placed into the si domain, when booting in iommu passthrough mode, then
removed. The RMRR information for such devices need to be re-processed
to avoid DMA Read errors due to the Present Bit being cleared in the
device's context entry.
Signed-off-by: Thomas Mingarelli <thomas.mingare...@hp.com>
Tested-by: Tony Camuso <tony.cam...@hp.com>
Details of testing performed (per Mr. Camuso):
I think I was able to prove that your patch works with si domain devices.
I was able to Device Assign the two Patsburg USB controllers on the DL360G8 to
your RH6 VM.
When I did that, I saw them on the VM guest, but they did not appear on the
host. This is exactly the behavior you expect for Device-Assigned devices.
Guest ..
[root@rh6 ~]# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device
001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID
8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID
0627:0001 Adomax Technology Co., Ltd Bus 002 Device 003: ID 0000:0000 Bus 001
Device 003: ID 046d:c03d Logitech, Inc. M-BT96a Pilot Optical Mouse
Host ...
[root@dl380g8 ~]# lsusb
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device
002: ID 03f0:7029 Hewlett-Packard
[root@dl380g8 ~]#
When I powered-down the guest, the USB controllers appeared on the host system
again.
[root@dl380g8 ~]# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device
001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 002: ID
03f0:7029 Hewlett-Packard Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0
root hub Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching
Hub Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 003: ID 046d:c03d Logitech, Inc. M-BT96a Pilot Optical Mouse Bus
002 Device 003: ID 0424:2660 Standard Microsystems Corp.
Bus 002 Device 004: ID 03f0:3207 Hewlett-Packard 4 GB flash drive
[root@dl380g8 ~]#
Then, I powered-up the guest again, the usb controllers were there on the guest
system again.
[root@localhost ~]# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device
001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID
8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID
0627:0001 Adomax Technology Co., Ltd Bus 002 Device 003: ID 0000:0000 Bus 001
Device 003: ID 046d:c03d Logitech, Inc. M-BT96a Pilot Optical Mouse
[root@localhost ~]#
And they had vanished from the host system.
[root@dl380g8 ~]# lsusb
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device
002: ID 03f0:7029 Hewlett-Packard
[root@dl380g8 ~]#
I believe this proves that your patch works correctly with si domain devices.
PATCH FOLLOWS...
diff -up linux-3.2.4/drivers/iommu/intel-iommu.c.ORIG
linux-3.2.4/drivers/iommu/intel-iommu.c
--- linux-3.2.4/drivers/iommu/intel-iommu.c.ORIG 2012-02-22
16:10:07.105254130 -0600
+++ linux-3.2.4/drivers/iommu/intel-iommu.c 2012-02-28 12:49:38.537694065
-0600
@@ -2676,7 +2676,8 @@ static int iommu_dummy(struct pci_dev *p
static int iommu_no_mapping(struct device *dev)
{
struct pci_dev *pdev;
- int found;
+ struct dmar_rmrr_unit *rmrr;
+ int i, ret, found;
if (unlikely(dev->bus != &pci_bus_type))
return 1;
@@ -2699,7 +2700,24 @@ static int iommu_no_mapping(struct devic
*/
domain_remove_one_dev_info(si_domain, pdev);
printk(KERN_INFO "32bit %s uses non-identity mapping\n",
- pci_name(pdev));
+ pci_name(pdev));
+ printk(KERN_INFO "IOMMU: Re-processing RMRR information
for device %s:\n",
+ pci_name(pdev));
+ for_each_rmrr_units(rmrr) {
+ for (i = 0; i < rmrr->devices_cnt; i++) {
+ /*
+ * Here we are just concerned with
finding the
+ * one device that was removed from the
+ * si_domain and re-evaluating its RMRR
info.
+ */
+ if (rmrr->devices[i] != pdev)
+ continue;
+ ret = iommu_prepare_rmrr_dev(rmrr,
pdev);
+ if (ret)
+ printk(KERN_ERR
+ "IOMMU: mapping
reserved region failed for device.\n");
+ }
+ }
return 0;
}
} else {
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