Additional info:
Devices properties which also lost:
PCI ACS capability register
PCI ACS compatible up hierarchy
PCI ACS support
PACI ARI support
PCI ECRC errors
PCI atomics supported
PCI correctable error mask
PCI error reporting
PCI firmware error handing
PCI uncorrectable error mask
PCI uncorrectable error severity

What about the same qemu cmdline with Linux guest?

Since it's specific issue with virtio-net/vhost, copying Jason.

(In reply to jinl from comment #1)
> Additional info:
> Devices properties which also lost:
> PCI ACS capability register
> PCI ACS compatible up hierarchy
> PCI ACS support
> PACI ARI support
> PCI ECRC errors
> PCI atomics supported
> PCI correctable error mask
> PCI error reporting
> PCI firmware error handing
> PCI uncorrectable error mask
> PCI uncorrectable error severity

Is the device identified as a PCI-E device or not in the guest?

Thanks

(In reply to Peter Xu from comment #2)
> What about the same qemu cmdline with Linux guest?
Linux guest works well with the same qemu cmdline.

(In reply to jason wang from comment #3)
> (In reply to jinl from comment #1)
> > Additional info:
> > Devices properties which also lost:
> > PCI ACS capability register
> > PCI ACS compatible up hierarchy
> > PCI ACS support
> > PACI ARI support
> > PCI ECRC errors
> > PCI atomics supported
> > PCI correctable error mask
> > PCI error reporting
> > PCI firmware error handing
> > PCI uncorrectable error mask
> > PCI uncorrectable error severity
> 
> Is the device identified as a PCI-E device or not in the guest?
> 
> Thanks

virtio-net-pci device is under pcie-root-port, so is identified as a PCI-E device in the guest.

hit the same issue with RHEL 9.1 host

Related BZ#2089545

*** Bug 2089545 has been marked as a duplicate of this bug. ***

MS support ticket: 2210030030001461

hit the same issue with win11 22H2
host env:
qemu-kvm-7.1.0-1.el9.x86_64
kernel-5.14.0-171.el9.x86_64

guest cmd:
/usr/libexec/qemu-kvm \
-name guest=win11,debug-threads=on \
-S \
-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain-9-win11/master-key.aes"}' \
-blockdev '{"driver":"file","filename":"/usr/share/edk2/ovmf/OVMF_CODE.secboot.fd","node-name":"libvirt-pflash0-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-pflash0-format","read-only":true,"driver":"raw","file":"libvirt-pflash0-storage"}' \
-blockdev '{"driver":"file","filename":"/var/lib/libvirt/qemu/nvram/win11_VARS.fd","node-name":"libvirt-pflash1-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-pflash1-format","read-only":false,"driver":"raw","file":"libvirt-pflash1-storage"}' \
-machine pc-q35-rhel9.0.0,usb=off,smm=on,kernel_irqchip=split,dump-guest-core=off,memory-backend=pc.ram,pflash0=libvirt-pflash0-format,pflash1=libvirt-pflash1-format \
-accel kvm \
-cpu Icelake-Server,ss=on,vmx=on,pdcm=on,hypervisor=on,tsc-adjust=on,avx512ifma=on,sha-ni=on,rdpid=on,fsrm=on,md-clear=on,stibp=on,arch-capabilities=on,xsaves=on,ibpb=on,ibrs=on,amd-stibp=on,amd-ssbd=on,rdctl-no=on,ibrs-all=on,skip-l1dfl-vmentry=on,mds-no=on,pschange-mc-no=on,tsx-ctrl=on,hle=off,rtm=off,mpx=off,intel-pt=off,hv-time=on,hv-relaxed=on,hv-vapic=on,hv-spinlocks=0x1fff,hv-vpindex=on,hv-runtime=on,hv-synic=on,hv-stimer=on,hv-stimer-direct=on,hv-reset=on,hv-frequencies=on,hv-reenlightenment=on,hv-tlbflush=on,hv-ipi=on,hv-evmcs=on \
-global driver=cfi.pflash01,property=secure,value=on \
-m 8192 \
-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":8589934592}' \
-overcommit mem-lock=off \
-smp 4,sockets=1,dies=1,cores=4,threads=1 \
-uuid 28807dcd-5c36-4ac8-ba2c-4d4cedbe998a \
-no-user-config \
-nodefaults \
-chardev socket,id=charmonitor,fd=22,server=on,wait=off \
-mon chardev=charmonitor,id=monitor,mode=control \
-rtc base=localtime,driftfix=slew \
-global kvm-pit.lost_tick_policy=delay \
-no-hpet \
-no-shutdown \
-global ICH9-LPC.disable_s3=1 \
-global ICH9-LPC.disable_s4=1 \
-boot strict=on \
-device '{"driver":"intel-iommu","id":"iommu0","intremap":"on","caching-mode":true,"eim":"on","device-iotlb":true}' \
-device '{"driver":"pcie-root-port","port":16,"chassis":1,"id":"pci.1","bus":"pcie.0","multifunction":true,"addr":"0x2"}' \
-device '{"driver":"pcie-root-port","port":17,"chassis":2,"id":"pci.2","bus":"pcie.0","addr":"0x2.0x1"}' \
-device '{"driver":"pcie-root-port","port":18,"chassis":3,"id":"pci.3","bus":"pcie.0","addr":"0x2.0x2"}' \
-device '{"driver":"pcie-root-port","port":19,"chassis":4,"id":"pci.4","bus":"pcie.0","addr":"0x2.0x3"}' \
-device '{"driver":"pcie-root-port","port":20,"chassis":5,"id":"pci.5","bus":"pcie.0","addr":"0x2.0x4"}' \
-device '{"driver":"pcie-root-port","port":21,"chassis":6,"id":"pci.6","bus":"pcie.0","addr":"0x2.0x5"}' \
-device '{"driver":"pcie-root-port","port":22,"chassis":7,"id":"pci.7","bus":"pcie.0","addr":"0x2.0x6"}' \
-device '{"driver":"pcie-root-port","port":23,"chassis":8,"id":"pci.8","bus":"pcie.0","addr":"0x2.0x7"}' \
-device '{"driver":"pcie-root-port","port":24,"chassis":9,"id":"pci.9","bus":"pcie.0","multifunction":true,"addr":"0x3"}' \
-device '{"driver":"pcie-root-port","port":25,"chassis":10,"id":"pci.10","bus":"pcie.0","addr":"0x3.0x1"}' \
-device '{"driver":"pcie-root-port","port":26,"chassis":11,"id":"pci.11","bus":"pcie.0","addr":"0x3.0x2"}' \
-device '{"driver":"pcie-root-port","port":27,"chassis":12,"id":"pci.12","bus":"pcie.0","addr":"0x3.0x3"}' \
-device '{"driver":"pcie-root-port","port":28,"chassis":13,"id":"pci.13","bus":"pcie.0","addr":"0x3.0x4"}' \
-device '{"driver":"pcie-root-port","port":29,"chassis":14,"id":"pci.14","bus":"pcie.0","addr":"0x3.0x5"}' \
-device '{"driver":"qemu-xhci","p2":15,"p3":15,"id":"usb","bus":"pci.3","addr":"0x0"}' \
-device '{"driver":"virtio-scsi-pci","iommu_platform":true,"ats":true,"id":"scsi0","bus":"pci.2","addr":"0x0"}' \
-blockdev '{"driver":"file","filename":"/home/win10.qcow2","node-name":"libvirt-4-storage","cache":{"direct":true,"no-flush":false},"auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-4-format","read-only":false,"discard":"unmap","cache":{"direct":true,"no-flush":false},"driver":"qcow2","file":"libvirt-4-storage","backing":null}' \
-device '{"driver":"scsi-hd","bus":"scsi0.0","channel":0,"scsi-id":0,"lun":0,"device_id":"drive-scsi0-0-0-0","drive":"libvirt-4-format","id":"scsi0-0-0-0","bootindex":1,"write-cache":"on"}' \
-device '{"driver":"ide-cd","bus":"ide.1","id":"sata0-0-1"}' \
-device '{"driver":"ide-cd","bus":"ide.2","id":"sata0-0-2"}' \
-device '{"driver":"ide-cd","bus":"ide.3","id":"sata0-0-3"}' \
-netdev tap,fd=24,vhost=on,vhostfd=26,id=hostnet0 \
-device '{"driver":"virtio-net-pci","iommu_platform":true,"ats":true,"netdev":"hostnet0","id":"net0","mac":"52:54:00:dc:d0:4c","bus":"pci.1","addr":"0x0"}' \
-add-fd set=0,fd=23,opaque=serial0-source \
-chardev file,id=charserial0,path=/dev/fdset/0,append=on \
-device '{"driver":"isa-serial","chardev":"charserial0","id":"serial0","index":0}' \
-chardev socket,id=chrtpm,path=/run/libvirt/qemu/swtpm/9-win11-swtpm.sock \
-tpmdev emulator,id=tpm-tpm0,chardev=chrtpm \
-device '{"driver":"tpm-crb","tpmdev":"tpm-tpm0","id":"tpm0"}' \
-device '{"driver":"usb-tablet","id":"input0","bus":"usb.0","port":"1"}' \
-audiodev '{"id":"audio1","driver":"none"}' \
-vnc 0.0.0.0:0,audiodev=audio1 \
-device '{"driver":"VGA","id":"video0","vgamem_mb":16,"bus":"pcie.0","addr":"0x1"}' \
-device '{"driver":"virtio-balloon-pci","id":"balloon0","bus":"pci.4","addr":"0x0"}' \

Issue summary:
================

Windows does not detect ATS property for Ethernet PCI controller when
firmware masks PCIE native hotplug capability in _OSC control


Versions of windows affected:
=============================

Server versions: Windows server 2016, windows server 2019, windows server 2022
Desktop versions: Windows 10, Windows 11.

From our testing, the versions of Windows earlier than those mentioned
above do not report/check for ATS availability even when the firmware
does not mask PCIE native hotplug in _OSC. It seems reporting ATS
status is only available in the above newer versions of the OS.

How to reproduce the issue?
============================

We have used the QEMU hypervisor to test for this issue.
Please refer to the following RedHat BZ for the QEMU commandline used:
https://bugzilla.redhat.com/show_bug.cgi?id=2089545

Additionally, one can use the following scripts:

https://github.com/ani-sinha/misc/blob/master/test-ats.sh
https://github.com/ani-sinha/misc/blob/master/test-ats-win11.sh

(Please adjust the locations of the images/binaries as per your host).

Note that the ethernet controller is attached to the pcie root port
which in turn is attached to the pci root complex.
The ATS property is for the pcie root port as mentioned in Intel VTD spec (1).

"--global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=on/off" will
mask/unmask the PCIE native hotplug reporting in _OSC from the
firmware in QEMU and thus the issue can be observed easily. Please see
(2). "on" will mask the bit, "off" will unmask.

"-snapshot" command line has been used with the disk image to make
sure there are no caching effect within the guest OS.
Further, we have tested by removing and re-adding the ethernet
controller from within the guest OS.
The results are the same.


References:

(1) Intel Virtualization technology for Directed I/O, section 8.5 -
Root Port ATS capability reporting structure.
(2) ACPI spec 5.1, section 6.2.11.3 - OSC Implementation Example for
PCI Host Bridge Devices