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

["Michael S. Tsirkin" <mst@redhat.com>]

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?

> 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/qemu/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
> > > > 
> > 
> >