Ping? The problem is still there... On 24/08/2018 13:04, Alexey Kardashevskiy wrote: > > > On 09/08/2018 14:41, Alexey Kardashevskiy wrote: >> >> >> On 25/07/2018 19:50, Alexey Kardashevskiy wrote: >>> I am trying to pass through a 3D controller: >>> [0302]: NVIDIA Corporation GV100GL [Tesla V100 SXM2] [10de:1db1] (rev a1) >>> >>> which has a quite unique feature as coherent memory directly accessible >>> from a POWER9 CPU via an NVLink2 transport. >>> >>> So in addition to passing a PCI device + accompanying NPU devices, >>> we will also be passing the host physical address range as it is done >>> on the bare metal system. >>> >>> The memory on the host is presented as: >>> >>> === >>> [aik@yc02goos ~]$ lsprop /proc/device-tree/memory@42000000000 >>> ibm,chip-id 000000fe (254) >>> device_type "memory" >>> compatible "ibm,coherent-device-memory" >>> reg 00000420 00000000 00000020 00000000 >>> linux,usable-memory >>> 00000420 00000000 00000000 00000000 >>> phandle 00000726 (1830) >>> name "memory" >>> ibm,associativity >>> 00000004 000000fe 000000fe 000000fe 000000fe >>> === >>> >>> and the host does not touch it as the second 64bit value of >>> "linux,usable-memory" - the size - is null. Later on the NVIDIA driver >>> trains the NVLink2 and probes this memory and this is how it becomes >>> onlined. >>> >>> In the virtual environment I am planning on doing the same thing, >>> however there is a difference in 64bit DMA handling. The powernv >>> platform uses a PHB3 bypass mode and that just works but >>> the pseries platform uses DDW RTAS API to achieve the same >>> result and the problem with this is that we need a huge DMA >>> window to start from zero (because this GPU supports less than >>> 50bits for DMA address space) and cover not just present memory >>> but also this new coherent memory. >>> >>> >>> This is based on sha1 >>> d72e90f3 Linus Torvalds "Linux 4.18-rc6". >>> >>> Please comment. Thanks. >> >> >> Ping? > > > Ping? > >> >> >>> >>> >>> >>> Alexey Kardashevskiy (3): >>> powerpc/pseries/iommu: Allow dynamic window to start from zero >>> powerpc/pseries/iommu: Force default DMA window removal >>> powerpc/pseries/iommu: Use memory@ nodes in max RAM address >>> calculation >>> >>> arch/powerpc/platforms/pseries/iommu.c | 77 ++++++++++++++++++++++++++++++---- >>> 1 file changed, 70 insertions(+), 7 deletions(-) >>> >> > -- Alexey
