Re: [Qemu-devel] Question: SRIOV support over Win Hyper-V VM running in QEMU process on Linux host

[Knut Omang]

On Thu, 2018-07-26 at 20:05 +0300, Marcel Apfelbaum wrote:
> 
> On 07/26/2018 07:42 PM, Knut Omang wrote:
> > On Thu, 2018-07-26 at 19:41 +0300, Michael S. Tsirkin wrote:
> > > On Thu, Jul 26, 2018 at 06:38:32PM +0200, Knut Omang wrote:
> > > > On Thu, 2018-07-26 at 18:51 +0300, Marcel Apfelbaum wrote:
> > > > > Hi
> > > > > 
> > > > > On 07/26/2018 05:52 PM, Stefan Hajnoczi wrote:
> > > > > > On Thu, Jul 12, 2018 at 07:33:14AM +0000, Elijah Shakkour wrote:
> > > > > > > Hey,
> > > > > > > 
> > > > > > > Our team is adding a NIC functional  emulation to QEMU.
> > > > > > > One of the features we are adding to this NIC is SRIOV.
> > > > > > > 
> > > > > > > Here is the error message I get when checking SRIOV support
> > > > > > > of  our
> > > > > > > emulated NIC on Win2016 server (the hyper-v VM).
> > > > > > > "
> > > > > > > SR-IOV cannot be used on this system as the PCI Express hardware
> > > > > > > does
> > > > > > > not
> > > > > > > support Access Control Services (ACS) at any root port.
> > > > > 
> > > > > QEMU's emulated PCI Express Root Ports do not support ACS yet, however
> > > > > I
> > > > > am not sure ACS is a prerequisite
> > > > > for SR-IOV. We would need ARI support for allowing more than 8VFs, but
> > > > > QEMU doesn't support that either (yet).
> > > > > 
> > > > > Knut Omag has some working patches, he successfully implemented SR-IOV
> > > > > with QEMU, see:
> > > > >        https://github.com/knuto/qemu/tree/sriov_patches_v7
> > > > > 
> > > > > The code was not merged since we need at least a device with SR-IOV
> > > > > support to justify the addition.
> > > > 
> > > > FYI, I recently rebased these to latest master but just didn't get to
> > > > push
> > > > them
> > > > out. I did just now - they are available here:
> > > > 
> > > >     https://github.com/knuto/qemu/tree/sriov_patches_v8
> > > > 
> > > > As far as I know ARI support with my patch set works just fine - I have
> > > > tested
> > > > it with lots of VFs.
> > > > 
> > > > One of the patches in the series (pci: Make use of the devfn property
> > > > when
> > > > registering new devices) is necessary to make ARI work as it should with
> > > > SR/IOV.
> > > > 
> > > > For the hardware model I developed the SR/IOV patches for, I also added
> > > > enough
> > > > ACS support in the root port (PCIe capability helper patch + usage in
> > > > ioh3420) to make VFIO "happy". I haven't submitted them because they
> > > > are "questionable" since they likely do not reflect the actual features
> > > > of
> > > > the
> > > > ioh3420.
> > > 
> > > In that the actual ioh3420 doesn't support ACS?
> > 
> > yes.. I don't have one so I don't know but that was my assumption..
> 
> Hi Knut,
> 
> We have now a generic PCIe Root Port we can add whatever we want to it.
> See please hw/pci-bridge/gen_pcie_root_port.c.

Ok, I see! - I wasn't aware of that. I was thinking more in terms of just 
emulating a slightly newer Intel root port but never got around to that.

> So your patches add both ARI and ACS support, nice!
> Maybe it worth merging at least these features.

I'll have a look at the generic root port, it is probably a natural extension 
for v9 of the sriov patch set :-)

Thanks,
Knut

> 
> Thanks,
> Marcel
> 
> > 
> > Knut
> > 
> > > > I can make those available if interesting.
> > > > 
> > > > Thanks,
> > > > Knut
> > > > 
> > > > > > > Contact your system vendor for further information.
> > > > > > > "
> > > > > > 
> > > > > > I'm not sure what the status of emulated SR-IOV is so I have CCed
> > > > > > Michael Tsirkin and Marcel Apfelbaum, the PCI maintainers in QEMU.
> > > > > 
> > > > > Thanks,
> > > > > Marcel
> > > > > 
> > > > > > > Could you please advise about what could be the issue here?
> > > > > > > 
> > > > > > > BTW: I use same configuration (VM XML file attached) when running
> > > > > > > linux VM
> > > > > > > (RH7.2) image (instead of Win Hyper-V) over the same host and
> > > > > > > SRIOV is
> > > > > > > working for me there.
> > > > > > > 
> > > > > > > Here the XML file I use to define the VM (our emulated NIC is
> > > > > > > added at
> > > > > > > the
> > > > > > > end of XML):
> > > > > > > "
> > > > > > > <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/q
> > > > > > > emu/
> > > > > > > 1.0'
> > > > > > > > ;
> > > > > > > 
> > > > > > >     <name>nst105</name>
> > > > > > >     <uuid>0249a525-2ee2-432b-a1f5-a6db83b089a3</uuid>
> > > > > > >     <memory unit='KiB'>8388608</memory>
> > > > > > >     <currentMemory unit='KiB'>8388608</currentMemory>
> > > > > > >     <vcpu placement='static'>8</vcpu>
> > > > > > >     <resource>
> > > > > > >       <partition>/machine</partition>
> > > > > > >     </resource>
> > > > > > >     <os>
> > > > > > >       <type arch='x86_64' machine='pc-q35-2.11'>hvm</type>
> > > > > > >     </os>
> > > > > > >     <features>
> > > > > > >       <acpi/>
> > > > > > >       <apic/>
> > > > > > >       <hyperv>
> > > > > > >         <relaxed state='on'/>
> > > > > > >         <vapic state='on'/>
> > > > > > >         <spinlocks state='on' retries='8191'/>
> > > > > > >       </hyperv>
> > > > > > >     </features>
> > > > > > >     <cpu mode='custom' match='exact' check='none'>
> > > > > > >       <model fallback='forbid'>SandyBridge</model>
> > > > > > >       <feature policy='require' name='hypervisor'/>
> > > > > > >       <feature policy='require' name='vmx'/>
> > > > > > >     </cpu>
> > > > > > >     <clock offset='localtime'>
> > > > > > >       <timer name='rtc' tickpolicy='catchup'/>
> > > > > > >       <timer name='pit' tickpolicy='delay'/>
> > > > > > >       <timer name='hpet' present='no'/>
> > > > > > >       <timer name='hypervclock' present='yes'/>
> > > > > > >     </clock>
> > > > > > >     <on_poweroff>destroy</on_poweroff>
> > > > > > >     <on_reboot>restart</on_reboot>
> > > > > > >     <on_crash>destroy</on_crash>
> > > > > > >     <pm>
> > > > > > >       <suspend-to-mem enabled='no'/>
> > > > > > >       <suspend-to-disk enabled='no'/>
> > > > > > >     </pm>
> > > > > > >     <devices>
> > > > > > >       <emulator>/opt/qemu/bin/qemu-system-x86_64</emulator>
> > > > > > >       <disk type='file' device='disk'>
> > > > > > >         <driver name='qemu' type='qcow2'/>
> > > > > > >         <source file='/images/nst105.qcow2'/>
> > > > > > >         <target dev='sda' bus='sata'/>
> > > > > > >         <boot order='2'/>
> > > > > > >         <address type='drive' controller='0' bus='0' target='0'
> > > > > > > unit='0'/>
> > > > > > >       </disk>
> > > > > > >       <controller type='usb' index='0' model='ich9-ehci1'>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x1d'
> > > > > > > function='0x7'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='usb' index='0' model='ich9-uhci1'>
> > > > > > >         <master startport='0'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x1d'
> > > > > > > function='0x0' multifunction='on'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='usb' index='0' model='ich9-uhci2'>
> > > > > > >         <master startport='2'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x1d'
> > > > > > > function='0x1'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='usb' index='0' model='ich9-uhci3'>
> > > > > > >         <master startport='4'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x1d'
> > > > > > > function='0x2'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='sata' index='0'>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x1f'
> > > > > > > function='0x2'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='pci' index='0' model='pcie-root'/>
> > > > > > >       <controller type='pci' index='1' model='pcie-root-port'>
> > > > > > >         <model name='pcie-root-port'/>
> > > > > > >         <target chassis='1' port='0x10'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x02'
> > > > > > > function='0x0' multifunction='on'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='pci' index='2' model='pcie-root-port'>
> > > > > > >         <model name='pcie-root-port'/>
> > > > > > >         <target chassis='2' port='0x11'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x02'
> > > > > > > function='0x1'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='pci' index='3' model='pcie-root-port'>
> > > > > > >         <model name='pcie-root-port'/>
> > > > > > >         <target chassis='3' port='0x12'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x02'
> > > > > > > function='0x2'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='pci' index='4' model='dmi-to-pci-bridge'>
> > > > > > >         <model name='i82801b11-bridge'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x1e'
> > > > > > > function='0x0'/>
> > > > > > >       </controller>
> > > > > > >       <controller type='pci' index='5' model='pci-bridge'>
> > > > > > >         <model name='pci-bridge'/>
> > > > > > >         <target chassisNr='5'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x04' slot='0x00'
> > > > > > > function='0x0'/>
> > > > > > >       </controller>
> > > > > > >       <interface type='bridge'>
> > > > > > >         <mac address='00:50:56:1b:dd:6f'/>
> > > > > > >         <source bridge='br0'/>
> > > > > > >         <model type='virtio'/>
> > > > > > >         <boot order='1'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x01' slot='0x00'
> > > > > > > function='0x0'/>
> > > > > > >       </interface>
> > > > > > >       <serial type='pty'>
> > > > > > >         <target port='0'/>
> > > > > > >       </serial>
> > > > > > >       <console type='pty'>
> > > > > > >         <target type='serial' port='0'/>
> > > > > > >       </console>
> > > > > > >       <input type='tablet' bus='usb'>
> > > > > > >         <address type='usb' bus='0' port='1'/>
> > > > > > >       </input>
> > > > > > >       <input type='mouse' bus='ps2'/>
> > > > > > >       <input type='keyboard' bus='ps2'/>
> > > > > > >       <graphics type='vnc' port='-1' autoport='yes'
> > > > > > > listen='127.0.0.1'
> > > > > > > keymap='en-us'>
> > > > > > >         <listen type='address' address='127.0.0.1'/>
> > > > > > >       </graphics>
> > > > > > >       <video>
> > > > > > >         <model type='vga' vram='16384' heads='1' primary='yes'/>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x00' slot='0x01'
> > > > > > > function='0x0'/>
> > > > > > >       </video>
> > > > > > >       <memballoon model='virtio'>
> > > > > > >         <address type='pci' domain='0x0000' bus='0x02' slot='0x00'
> > > > > > > function='0x0'/>
> > > > > > >       </memballoon>
> > > > > > >     </devices>
> > > > > > >     <seclabel type='none' model='none'/>
> > > > > > >     <seclabel type='dynamic' model='dac' relabel='yes'/>
> > > > > > >     <qemu:commandline>
> > > > > > >       <qemu:arg value='-device'/>
> > > > > > >       <qemu:arg value='pcie-root-port,pref64-
> > > > > > > reserve=500M,slot=0,id=pcie_port.1'/>
> > > > > > >       <qemu:arg value='-netdev'/>
> > > > > > >       <qemu:arg
> > > > > > > value='tap,id=tap5,ifname=tap5,script=no,downscript=no'/>
> > > > > > >       <qemu:arg value='-device'/>
> > > > > > >       <qemu:arg value='my_emu_nic,netdev=tap5,bus=pcie_port.1'/>
> > > > > > >     </qemu:commandline>
> > > > > > > </domain>
> > > > > > > "
> > > > > > > ______________________
> > > > > > > General info:
> > > > > > > Host OS: RH7.0 (Kernel: 4.14.13)
> > > > > > > QEMU version: 2.11
> > > > > > > libvirt version: 3.2.0
> > > > > > > Running the following on the host shows that both nested and IOMMU
> > > > > > > are
> > > > > > > enabled:
> > > > > > > ~]#: cat /sys/module/kvm_intel/parameters/nested
> > > > > > > Y
> > > > > > > ~]# dmesg | grep -e DMAR -e IOMMU
> > > > > > > [    0.000000] DMAR: IOMMU enabled
> > > > > > > 
> > > > > > > Thanks,
> > > > > > > Elijah
> > > > > > > 
> 
>