* About VT-d on ASUS P6T
@ 2010-05-11 10:09 Felix Kuperjans
2010-05-12 1:54 ` Han, Weidong
0 siblings, 1 reply; 5+ messages in thread
From: Felix Kuperjans @ 2010-05-11 10:09 UTC (permalink / raw)
To: xen-devel
Hi,
as I posted on xen-users, I've successfully used pci passtrough on an ASUS P6T mainboard which is known to have really buggy RMRR tables.
I needed the iommu=passtrough and iommu_inclusive_mapping=1 command line options, combined with a little change to the RMRR parsing code:
dmar.c:
@@ -559,8 +558,7 @@
dprintk(XENLOG_WARNING VTDPREFIX,
" The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
rmrru->base_address, rmrru->end_address);
- xfree(rmrru);
- ret = -EFAULT;
+ acpi_register_rmrr_unit(rmrru);
}
else
{
This way, the condition that causes the error printed above, does not lead to an abortion of VT-d code, but instead registers the RMRR unit as if it was correct.
VT-d is working properly afterwards and I've tested some devices successfully.
Probably, you would prefer to choose the action based on some command line option (like iommu_inclusive_mapping=1) instead of ignoring this error by default.
Regards,
Felix
^ permalink raw reply [flat|nested] 5+ messages in thread* RE: About VT-d on ASUS P6T
2010-05-11 10:09 About VT-d on ASUS P6T Felix Kuperjans
@ 2010-05-12 1:54 ` Han, Weidong
2010-05-12 8:57 ` Felix Kuperjans
0 siblings, 1 reply; 5+ messages in thread
From: Han, Weidong @ 2010-05-12 1:54 UTC (permalink / raw)
To: Felix Kuperjans, xen-devel@lists.xensource.com
Your code changes just let xen not disable VT-d, but actually "iommu=passthrough" avoids problems of incorrect RMRR. This option makes dom0 not use VT-d, therefore incorrect RMRR won't be used by device. But if you assign the device whose RMRR incorrect to guest, it still causes problems.
Regards,
Weidong
-----Original Message-----
From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Felix Kuperjans
Sent: Tuesday, May 11, 2010 6:09 PM
To: xen-devel@lists.xensource.com
Subject: [Xen-devel] About VT-d on ASUS P6T
Hi,
as I posted on xen-users, I've successfully used pci passtrough on an ASUS P6T mainboard which is known to have really buggy RMRR tables.
I needed the iommu=passtrough and iommu_inclusive_mapping=1 command line options, combined with a little change to the RMRR parsing code:
dmar.c:
@@ -559,8 +558,7 @@
dprintk(XENLOG_WARNING VTDPREFIX,
" The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
rmrru->base_address, rmrru->end_address);
- xfree(rmrru);
- ret = -EFAULT;
+ acpi_register_rmrr_unit(rmrru);
}
else
{
This way, the condition that causes the error printed above, does not lead to an abortion of VT-d code, but instead registers the RMRR unit as if it was correct.
VT-d is working properly afterwards and I've tested some devices successfully.
Probably, you would prefer to choose the action based on some command line option (like iommu_inclusive_mapping=1) instead of ignoring this error by default.
Regards,
Felix
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: About VT-d on ASUS P6T
2010-05-12 1:54 ` Han, Weidong
@ 2010-05-12 8:57 ` Felix Kuperjans
2010-05-12 10:11 ` Han, Weidong
0 siblings, 1 reply; 5+ messages in thread
From: Felix Kuperjans @ 2010-05-12 8:57 UTC (permalink / raw)
To: xen-devel
So there will be some devices that do not work while others work - can I
figure out which devices are affected by the incorrect RMRR?
In addition, only setting iommu=passtrough caused XEN to disable VT-d
completely, altough some devices actually can be passtroughed to the
domU perfectly.
Regards,
Felix
Am 12.05.2010 03:54, schrieb Han, Weidong:
> Your code changes just let xen not disable VT-d, but actually "iommu=passthrough" avoids problems of incorrect RMRR. This option makes dom0 not use VT-d, therefore incorrect RMRR won't be used by device. But if you assign the device whose RMRR incorrect to guest, it still causes problems.
>
> Regards,
> Weidong
>
> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Felix Kuperjans
> Sent: Tuesday, May 11, 2010 6:09 PM
> To: xen-devel@lists.xensource.com
> Subject: [Xen-devel] About VT-d on ASUS P6T
>
> Hi,
>
> as I posted on xen-users, I've successfully used pci passtrough on an ASUS P6T mainboard which is known to have really buggy RMRR tables.
>
> I needed the iommu=passtrough and iommu_inclusive_mapping=1 command line options, combined with a little change to the RMRR parsing code:
>
> dmar.c:
>
> @@ -559,8 +558,7 @@
> dprintk(XENLOG_WARNING VTDPREFIX,
> " The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
> rmrru->base_address, rmrru->end_address);
> - xfree(rmrru);
> - ret = -EFAULT;
> + acpi_register_rmrr_unit(rmrru);
> }
> else
> {
>
> This way, the condition that causes the error printed above, does not lead to an abortion of VT-d code, but instead registers the RMRR unit as if it was correct.
> VT-d is working properly afterwards and I've tested some devices successfully.
>
> Probably, you would prefer to choose the action based on some command line option (like iommu_inclusive_mapping=1) instead of ignoring this error by default.
>
> Regards,
> Felix
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread* RE: About VT-d on ASUS P6T
2010-05-12 8:57 ` Felix Kuperjans
@ 2010-05-12 10:11 ` Han, Weidong
0 siblings, 0 replies; 5+ messages in thread
From: Han, Weidong @ 2010-05-12 10:11 UTC (permalink / raw)
To: Felix Kuperjans, xen-devel@lists.xensource.com
>So there will be some devices that do not work while others work - can I
>figure out which devices are affected by the incorrect RMRR?
"iommu=verbose" will list all RMRRs and their relevant devices.
>In addition, only setting iommu=passtrough caused XEN to disable VT-d
>completely, altough some devices actually can be passtroughed to the
>domU perfectly.
Yes, only setting iommu=passthrough causes Xen to disable VT-d, because acpi_parse_one_rmrr returns "-EFAULT" when a RMRR is incorrect. Indeed, incorrect RMRR only impacts its relevant device, but it requires setting iommu=passthrough, and also it causes problems when assign corresponding devices. It's an "obvious" issue of BIOS. There is not a clean way to handle this BIOS issue in Xen upstream. Of course, you can hack it by yourself to work for you. But I encourage you to report it to the vendor and get it fixed in BIOS.
Regards,
Weidong
Am 12.05.2010 03:54, schrieb Han, Weidong:
> Your code changes just let xen not disable VT-d, but actually "iommu=passthrough" avoids problems of incorrect RMRR. This option makes dom0 not use VT-d, therefore incorrect RMRR won't be used by device. But if you assign the device whose RMRR incorrect to guest, it still causes problems.
>
> Regards,
> Weidong
>
> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Felix Kuperjans
> Sent: Tuesday, May 11, 2010 6:09 PM
> To: xen-devel@lists.xensource.com
> Subject: [Xen-devel] About VT-d on ASUS P6T
>
> Hi,
>
> as I posted on xen-users, I've successfully used pci passtrough on an ASUS P6T mainboard which is known to have really buggy RMRR tables.
>
> I needed the iommu=passtrough and iommu_inclusive_mapping=1 command line options, combined with a little change to the RMRR parsing code:
>
> dmar.c:
>
> @@ -559,8 +558,7 @@
> dprintk(XENLOG_WARNING VTDPREFIX,
> " The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
> rmrru->base_address, rmrru->end_address);
> - xfree(rmrru);
> - ret = -EFAULT;
> + acpi_register_rmrr_unit(rmrru);
> }
> else
> {
>
> This way, the condition that causes the error printed above, does not lead to an abortion of VT-d code, but instead registers the RMRR unit as if it was correct.
> VT-d is working properly afterwards and I've tested some devices successfully.
>
> Probably, you would prefer to choose the action based on some command line option (like iommu_inclusive_mapping=1) instead of ignoring this error by default.
>
> Regards,
> Felix
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
>
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread
* About VT-d on ASUS P6T
@ 2010-05-11 9:59 Felix Kuperjans
0 siblings, 0 replies; 5+ messages in thread
From: Felix Kuperjans @ 2010-05-11 9:59 UTC (permalink / raw)
To: xen-devel
Hi,
as I posted on xen-users, I've successfully used pci passtrough on an
ASUS P6T mainboard which is known to have really buggy RMRR tables.
I needed the iommu=passtrough and iommu_inclusive_mapping=1 command line
options, combined with a little change to the RMRR parsing code:
dmar.c:
@@ -559,8 +558,7 @@
dprintk(XENLOG_WARNING VTDPREFIX,
" The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
rmrru->base_address, rmrru->end_address);
- xfree(rmrru);
- ret = -EFAULT;
+ acpi_register_rmrr_unit(rmrru);
}
else
{
This way, the condition that causes the error printed above, does not
lead to an abortion of VT-d code, but instead registers the RMRR unit as
if it was correct.
VT-d is working properly afterwards and I've tested some devices
successfully.
Probably, you would prefer to choose the action based on some command
line option (like iommu_inclusive_mapping=1) instead of ignoring this
error by default.
Regards,
Felix
^ permalink raw reply [flat|nested] 5+ messages in thread
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2010-05-11 10:09 About VT-d on ASUS P6T Felix Kuperjans
2010-05-12 1:54 ` Han, Weidong
2010-05-12 8:57 ` Felix Kuperjans
2010-05-12 10:11 ` Han, Weidong
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