Subject: Re: [PATCH V7 00/17] Enable SRIOV on POWER8

From: Bjorn Helgaas <[email-masked]>
Date: Tue, 19 Aug 2014 15:19:42 -0600

On Thu, Jul 24, 2014 at 02:22:10PM +0800, Wei Yang wrote:
> This patch set enables the SRIOV on POWER8.
> 
> The gerneral idea is put each VF into one individual PE and allocate required
> resources like DMA/MSI.
> 
> One thing special for VF PE is we use M64BT to cover the IOV BAR. M64BT is one
> hardware on POWER platform to map MMIO address to PE. By using M64BT, we could
> map one individual VF to a VF PE, which introduce more flexiblity to users.
> 
> To achieve this effect, we need to do some hack on pci devices's resources.
> 1. Expand the IOV BAR properly.
>    Done by pnv_pci_ioda_fixup_iov_resources().
> 2. Shift the IOV BAR properly.
>    Done by pnv_pci_vf_resource_shift().
> 3. IOV BAR alignment is the total size instead of an individual size on
>    powernv platform.
>    Done by pnv_pcibios_sriov_resource_alignment().
> 4. Take the IOV BAR alignment into consideration in the sizing and assigning.
>    This is achieved by commit: "PCI: Take additional IOV BAR alignment in
>    sizing and assigning"
> 
> Test Environment:
>        The SRIOV device tested is Emulex Lancer and Mellanox ConnectX-3 on
>        POWER8.
> 
> Examples on pass through a VF to guest through vfio:
> 	1. install necessary modules
> 	   modprobe vfio
> 	   modprobe vfio-pci
> 	2. retrieve the iommu_group the device belongs to
> 	   readlink /sys/bus/pci/devices/0000:06:0d.0/iommu_group
> 	   ../../../../kernel/iommu_groups/26
> 	   This means it belongs to group 26
> 	3. see how many devices under this iommu_group
> 	   ls /sys/kernel/iommu_groups/26/devices/
> 	4. unbind the original driver and bind to vfio-pci driver
> 	   echo 0000:06:0d.0 > /sys/bus/pci/devices/0000:06:0d.0/driver/unbind
> 	   echo  1102 0002 > /sys/bus/pci/drivers/vfio-pci/new_id
> 	   Note: this should be done for each device in the same iommu_group
> 	5. Start qemu and pass device through vfio
> 	   /home/ywywyang/git/qemu-impreza/ppc64-softmmu/qemu-system-ppc64 \
> 		   -M pseries -m 2048 -enable-kvm -nographic \
> 		   -drive file=/home/ywywyang/kvm/fc19.img \
> 		   -monitor telnet:localhost:5435,server,nowait -boot cd \
> 		   -device "spapr-pci-vfio-host-bridge,id=CXGB3,iommu=26,index=6"
> 
> Verify this is the exact VF response:
> 	1. ping from a machine in the same subnet(the broadcast domain)
> 	2. run arp -n on this machine
> 	   9.115.251.20             ether   00:00:c9:df:ed:bf   C eth0
> 	3. ifconfig in the guest
> 	   # ifconfig eth1
> 	   eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
> 	        inet 9.115.251.20  netmask 255.255.255.0  broadcast 9.115.251.255
> 		inet6 fe80::200:c9ff:fedf:edbf  prefixlen 64  scopeid 0x20<link>
> 	        ether 00:00:c9:df:ed:bf  txqueuelen 1000 (Ethernet)
> 	        RX packets 175  bytes 13278 (12.9 KiB)
> 	        RX errors 0  dropped 0  overruns 0  frame 0
> 		TX packets 58  bytes 9276 (9.0 KiB)
> 	        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
> 	4. They have the same MAC address
> 
> 	Note: make sure you shutdown other network interfaces in guest.
> 
> ---
> v6 -> v7:
>    1. add IORESOURCE_ARCH flag for IOV BAR on powernv platform.
>    2. when IOV BAR has IORESOURCE_ARCH flag, the size is retrieved from
>       hardware directly. If not, calculate as usual.
>    3. reorder the patch set, group them by subsystem:
>       PCI, powerpc, powernv
>    4. rebase it on 3.16-rc6

This doesn't apply for me on v3.16-rc6:

  02:48:57 ~/linux$ stg rebase v3.16-rc6
  Checking for changes in the working directory ... done
  Rebasing to "v3.16-rc6" ... done
  No patches applied
  02:49:14 ~/linux$ stg import -M --sign m/wy
  Checking for changes in the working directory ... done
  Importing patch "pci-iov-export-interface-for" ... done
  Importing patch "pci-iov-get-vf-bar-size-from" ... done
  Importing patch "pci-add-weak" ... done
  Importing patch "pci-take-additional-iov-bar" ... done
  Importing patch "powerpc-pci-don-t-unset-pci" ... done
  Importing patch "powerpc-pci-define" ... done
  Importing patch "powrepc-pci-refactor-pci_dn" ... done
  Importing patch "powerpc-powernv-use-pci_dn-in" ... error: patch failed:
  arch/powerpc/platforms/powernv/pci.c:376
  error: arch/powerpc/platforms/powernv/pci.c: patch does not apply
  stg import: Diff does not apply cleanly

What am I missing?

I assume you intend these all to go through my tree just to keep them all
together.  The ideal rebase target for me would be v3.17-rc1.

Given the arch/powerpc parts, I'll want an ack from Ben.  I just chatted
with him about these, so I assume that's not a problem, but we should make
it explicit.

Bjorn