Hi Bjorn,
Am 08.05.2018 um 01:13 schrieb Bjorn Helgaas:
[+to Alex]
Alex,
Are you happy with this strategy of turning off ACS based on
CONFIG_PCI_P2PDMA? We only check this at enumeration-time and
I don't know if there are other places we would care?
thanks for pointing this out, I totally
Am 09.05.2018 um 15:12 schrieb Stephen Bates:
Jerome and Christian
I think there is confusion here, Alex properly explained the scheme
PCIE-device do a ATS request to the IOMMU which returns a valid
translation for a virtual address. Device can then use that address
directly without going
Am 09.05.2018 um 18:45 schrieb Logan Gunthorpe:
On 09/05/18 07:40 AM, Christian König wrote:
The key takeaway is that when any device has ATS enabled you can't
disable ACS without breaking it (even if you unplug and replug it).
I don't follow how you came to this conclusion...
The ACS bits
Am 10.05.2018 um 16:20 schrieb Stephen Bates:
Hi Jerome
As it is tie to PASID this is done using IOMMU so looks for caller
of amd_iommu_bind_pasid() or intel_svm_bind_mm() in GPU the existing
user is the AMD GPU driver see:
Ah thanks. This cleared things up for me. A quick search shows
Am 10.05.2018 um 19:15 schrieb Logan Gunthorpe:
On 10/05/18 11:11 AM, Stephen Bates wrote:
Not to me. In the p2pdma code we specifically program DMA engines with
the PCI bus address.
Ah yes of course. Brain fart on my part. We are not programming the P2PDMA
initiator with an IOVA but with
Am 08.05.2018 um 18:27 schrieb Logan Gunthorpe:
On 08/05/18 01:17 AM, Christian König wrote:
AMD APUs mandatory need the ACS flag set for the GPU integrated in the
CPU when IOMMU is enabled or otherwise you will break SVM.
Well, given that the current set only disables ACS bits on bridges
Am 08.05.2018 um 16:25 schrieb Stephen Bates:
Hi Christian
AMD APUs mandatory need the ACS flag set for the GPU integrated in the
CPU when IOMMU is enabled or otherwise you will break SVM.
OK but in this case aren't you losing (many of) the benefits of P2P since all
DMAs will now get
Am 03.05.2018 um 20:43 schrieb Logan Gunthorpe:
On 03/05/18 11:29 AM, Christian König wrote:
Ok, that is the point where I'm stuck. Why do we need that in one
function call in the PCIe subsystem?
The problem at least with GPUs is that we seriously don't have that
information here, cause
Hi Logan,
it would be rather nice to have if you could separate out the functions
to detect if peer2peer is possible between two devices.
That would allow me to reuse the same logic for GPU peer2peer where I
don't really have ZONE_DEVICE.
Regards,
Christian.
Am 24.04.2018 um 01:30 schrieb
Am 02.05.2018 um 17:56 schrieb Logan Gunthorpe:
Hi Christian,
On 5/2/2018 5:51 AM, Christian König wrote:
it would be rather nice to have if you could separate out the
functions to detect if peer2peer is possible between two devices.
This would essentially be pci_p2pdma_distance
Am 03.05.2018 um 17:59 schrieb Logan Gunthorpe:
On 03/05/18 03:05 AM, Christian König wrote:
Second question is how to you want to handle things when device are not
behind the same root port (which is perfectly possible in the cases I
deal with)?
I think we need to implement a whitelist
11 matches
Mail list logo
