@DustyArmstrong said:

@TeddyAstie yarp.

My bad, the VM has it as 00:08.0 but on the host it's actually 00:06.0, I just didn't think about the specifics of your request!

06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Barcelo (rev c1) (prog-if 00 [VGA controller])
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device 1636
	Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Interrupt: pin A routed to IRQ 38
	Region 0: Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Region 2: Memory at e0000000 (64-bit, prefetchable) [size=2M]
	Region 4: I/O ports at d000 [size=256]
	Region 5: Memory at fca00000 (32-bit, non-prefetchable) [size=512K]
	Capabilities: [48] Vendor Specific Information: Len=08 <?>
	Capabilities: [50] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1+,D2+,D3hot+,D3cold+)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [64] Express (v2) Legacy Endpoint, MSI 00
		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s <4us, L1 unlimited
			ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
		DevCtl:	Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
			RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 256 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- UncorrErr+ FatalErr- UnsuppReq+ AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 8GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <64ns, L1 <1us
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 8GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+, LTR-, OBFF Not Supported
		DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled
		LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis-
			 Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
			 Compliance De-emphasis: -6dB
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete+, EqualizationPhase1+
			 EqualizationPhase2+, EqualizationPhase3+, LinkEqualizationRequest-
	Capabilities: [a0] MSI: Enable- Count=1/4 Maskable- 64bit+
		Address: 0000000000000000  Data: 0000
	Capabilities: [c0] MSI-X: Enable- Count=4 Masked-
		Vector table: BAR=5 offset=00042000
		PBA: BAR=5 offset=00043000
	Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
	Capabilities: [270 v1] #19
	Capabilities: [2a0 v1] Access Control Services
		ACSCap:	SrcValid- TransBlk- ReqRedir- CmpltRedir- UpstreamFwd- EgressCtrl- DirectTrans-
		ACSCtl:	SrcValid- TransBlk- ReqRedir- CmpltRedir- UpstreamFwd- EgressCtrl- DirectTrans-
	Capabilities: [2b0 v1] Address Translation Service (ATS)
		ATSCap:	Invalidate Queue Depth: 00
		ATSCtl:	Enable-, Smallest Translation Unit: 00
	Capabilities: [2c0 v1] Page Request Interface (PRI)
		PRICtl: Enable- Reset-
		PRISta: RF- UPRGI- Stopped+
		Page Request Capacity: 00000100, Page Request Allocation: 00000000
	Capabilities: [2d0 v1] Process Address Space ID (PASID)
		PASIDCap: Exec+ Priv+, Max PASID Width: 10
		PASIDCtl: Enable- Exec- Priv-
	Capabilities: [400 v1] #25
	Capabilities: [410 v1] #26
	Capabilities: [440 v1] #27
	Kernel driver in use: pciback

thanks.

So basically, there is a more annoying issue, as the device doesn't even have a ROMBAR, in this case, the VBIOS is likely in the VFCT ACPI table of host (which the guest can't see); which needs to be injected as a "fake" rombar for the guest to behave properly.

That doable on its own, but it's quite tricky to integrate (and you would e.g need to extract VBIOS from VFCT using external tools).

I just discussed with Xen/AMD people, and there are known issues regarding PCI Passthrough of integrated AMD GPUs (not specific to Xen AFAIU). There are some projects regarding alternative approaches to bring AMD GPUs to VMs (virtio-gpu native context) which is the current focus.

@gb.123 said in XCP-ng 8.3 updates announcements and testing:

Here is the summary:

If USB Keyboard & Mouse is passed-through along-with GPU:
The GPU gets stuck in D3 state (on Shutdown/Restart of VM) (Classic GPU reset problem)

If no vUSB is passed but GPU is passed through:
The GPU works correctly and resets correctly (on Shutdown/Restart of VM)

I have no clue what vUSB may change regarding GPU passthrough.

When I run :

$> lspci
Extract of Output (Partial):

07:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] Device 15b8

However, this controller does not show up when I run :
xe pci-list

Is it a bug that lspci & xe pci-list have different number of devices ?

How can I pass this controller since xe pci-list does not show it so I can't get the UUID ?
Will kernel parameters (like XCP-ng 8.2) work in this case ?

Question for @Team-XAPI-Network regarding the filtering on PCI IDs.
I don't think XAPI allows using arbitrary BDF, but I may be wrong.

Is it safe to run on XCP-ng host ?

 echo 1 > /sys/bus/pci/rescan

(I'm trying to find a way where the PCI card is reset by the host without complete reboot, though I am aware that the above command will not reset it.)

Probably. But it's not going to change anything as the device doesn't completely leave the Dom0 when passed-through.
FYI a function-level-reset is systematically performed by Xen when doing PCI passthrough, thus your device should be reset before entering another guest (aside reset bugs like you may have).

Also is it advisable to use :

xl pci-assignable-add 07:00.0

in XCP-ng 8.3 ? or is this method deprecated ?

I don't think XAPI supports this PCI passthrough approach.
This is a command which allows dynamically to remove a device from Dom0 and put it into "quarantine domain", so that it will be ready to passthrough it.

Current XAPI uses the approach of having a set of "passthrough-able" devices at boot time by modifying the xen-pciback.hide kernel parameter, which does the same but at boot time.

Hello !

I am looking to get some feedback and evaluation on a performance-related patch for Xen (XCP-ng 8.3 only).
This patch changes the memcpy implementation of Xen to use the "ERMS variant" (aka REP MOVSB) instead of the current REP MOVSQ+B implementation.
This is expected to perform better on the vast majority of Intel CPUs and modern AMD ones (Zen3+), but may perform worse on some older AMD CPUs.

This change may impact the performance of PV drivers (especially network).

You can find more details regarding this proposed change in : https://github.com/xcp-ng-rpms/xen/pull/54
This change may be reworked in the future to take more in account the specificities of each CPUs (e.g check presence of ERMS flag).

Keep in mind that this patched version is experimental and not officially supported.

Installation :

# Download repo file for XCP-ng 8.3
wget https://koji.xcp-ng.org/repos/user/8/8.3/xcpng-users.repo -O /etc/yum.repos.d/xcpng-users.repo

# Installing the patched Xen packages (you should see `.erms` packages)
yum update --enablerepo=xcp-ng-tae1

You can revert the changes by downgrading the Xen package with the ones in the default repos.

yum downgrade --disablerepo=xcp-ng-tae1 "xen-*"

TSnake41 opened this pull request in xcp-ng-rpms/xen

draft Use ERMS variant for memcpy #54

@plaidypus I don't know a lot about NUMA on Xen, but we have a part in the docs regarding that
https://docs.xcp-ng.org/compute/#numa-affinity

And also other documentation on the subject
https://xapi-project.github.io/new-docs/toolstack/features/NUMA/index.html
there was a design session regarding NUMA in latest Xen Summit : https://youtu.be/KoNwEYMlhyU?list=PLQMQQsKgvLnvjRgDnb-5T51e1kGHgs1SO

@dcskinner @olivierlambert

You can read key/values from the xenstore, and write some (from VM to outside), but you cannot write values "in live" from outside the VM to the inside.

It is, but XAPI doesn't provide a interface for it.

do the guest tools quiesce the filesystems before snapshotting?

Tools are aware of a snapshot so you don't have blocks in flight.

do the guest tools quiesce the filesystems before snapshotting?

Guests kernel are aware, as it is them that are performing a "suspend" on toolstack request (thus quiece filesystems); although "tools" can only observe that the system has been suspended after the fact by measuring side effects, and not orchestrate it.

It's because suspend/resume operation doesn't come from "guest tools" actually, but instead from the kernel drivers. So userland tools has no say on it.

Hello,

Make sure Intel VMD is disabled (this is the hardware RAID feature of Intel, and it doesn't currently work on XCP-ng; you probably don't need it unless you are looking to make a RAID). We found some modern platforms enabling by default (which also causes issues with Windows).

@tuxen said (https://xcp-ng.org/forum/topic/3652/no-free-virtual-function-found-vgpu-s7150/4?_=1731502751059)

After some digging, could be the case of a GPU firmware being incompatible with UEFI. Do you have any spare server for testing XCP-ng boot in legacy/BIOS with this GPU?

Perhaps it is the issue ?

@ohajek

Nov 13 11:30:21 xen03 kernel: [10188.720655] AMD IOMMUv2 driver by Joerg Roedel jroedel@suse.de
Nov 13 11:30:21 xen03 kernel: [10188.720656] AMD IOMMUv2 functionality not available on this system

This is expected, Dom0 Kernel (Linux) is not supposed to access the IOMMU when it is already used by Xen. To check if AMD-Vi is working, you need to check xl dmesg instead.

I took a quick look at kern_gim_compiled.txt, and it look likes it timed-out somewhere

Oct 23 20:49:32 xen03 kernel: [   80.657394]        gim error:(wait_cmd_complete:2387)  wait_cmd_complete -- time out after 0.003004460 sec
Oct 23 20:49:32 xen03 kernel: [   80.657408]        gim error:(wait_cmd_complete:2390)   Cmd = 0x17, Status = 0x0, cmd_Complete=0

3ms looks like a short timeout for me, but aside that, it looks like a driver(gim) or hardware issue

@antest can you retry after doing /opt/xensource/libexec/xen-cmdline --set-xen iommu=debug then rebooting.
And also reporting full DomU and Dom0 dmesg (in addition to xl dmesg) ?

@abudef Note that even with this update, nested virtualization is still not really supported in XCP-ng 8.3.
It's there, you can enable it at your own risk. It broke due to some change in XAPI (even though Xen hypervisor had "support" for it).
It never actually got removed from Xen hypervisor (it was marked experimental in Xen 4.13 used in XCP-ng 8.2, it is also the case for Xen 4.17), although nothing really changed, it still has the same issues and limitations as said.

The current state of nested virtualization in Xen is quite clumsy and there are future plans to remake it properly from ground without taking shortcuts and have proper tests to back it.

Aside that, after some experiments, it seems that mostly nested EPT is incomplete/buggy, so your L1 hypervisor should not rely on it. You should add hap=0 to nested XCP-ng Xen cmdline. Beware that it will imply a pretty large performance hit, but I had more consistent results with this.
I am quite suprised that Windows works while Linux don't, maybe it is somewhat related to PV drivers ?

@DustyArmstrong said:

@TeddyAstie yarp.

My bad, the VM has it as 00:08.0 but on the host it's actually 00:06.0, I just didn't think about the specifics of your request!

06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Barcelo (rev c1) (prog-if 00 [VGA controller])
	Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device 1636
	Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Interrupt: pin A routed to IRQ 38
	Region 0: Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Region 2: Memory at e0000000 (64-bit, prefetchable) [size=2M]
	Region 4: I/O ports at d000 [size=256]
	Region 5: Memory at fca00000 (32-bit, non-prefetchable) [size=512K]
	Capabilities: [48] Vendor Specific Information: Len=08 <?>
	Capabilities: [50] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1+,D2+,D3hot+,D3cold+)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [64] Express (v2) Legacy Endpoint, MSI 00
		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s <4us, L1 unlimited
			ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
		DevCtl:	Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
			RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+
			MaxPayload 256 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- UncorrErr+ FatalErr- UnsuppReq+ AuxPwr- TransPend-
		LnkCap:	Port #0, Speed 8GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <64ns, L1 <1us
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 8GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+, LTR-, OBFF Not Supported
		DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled
		LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis-
			 Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
			 Compliance De-emphasis: -6dB
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete+, EqualizationPhase1+
			 EqualizationPhase2+, EqualizationPhase3+, LinkEqualizationRequest-
	Capabilities: [a0] MSI: Enable- Count=1/4 Maskable- 64bit+
		Address: 0000000000000000  Data: 0000
	Capabilities: [c0] MSI-X: Enable- Count=4 Masked-
		Vector table: BAR=5 offset=00042000
		PBA: BAR=5 offset=00043000
	Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
	Capabilities: [270 v1] #19
	Capabilities: [2a0 v1] Access Control Services
		ACSCap:	SrcValid- TransBlk- ReqRedir- CmpltRedir- UpstreamFwd- EgressCtrl- DirectTrans-
		ACSCtl:	SrcValid- TransBlk- ReqRedir- CmpltRedir- UpstreamFwd- EgressCtrl- DirectTrans-
	Capabilities: [2b0 v1] Address Translation Service (ATS)
		ATSCap:	Invalidate Queue Depth: 00
		ATSCtl:	Enable-, Smallest Translation Unit: 00
	Capabilities: [2c0 v1] Page Request Interface (PRI)
		PRICtl: Enable- Reset-
		PRISta: RF- UPRGI- Stopped+
		Page Request Capacity: 00000100, Page Request Allocation: 00000000
	Capabilities: [2d0 v1] Process Address Space ID (PASID)
		PASIDCap: Exec+ Priv+, Max PASID Width: 10
		PASIDCtl: Enable- Exec- Priv-
	Capabilities: [400 v1] #25
	Capabilities: [410 v1] #26
	Capabilities: [440 v1] #27
	Kernel driver in use: pciback

thanks.

So basically, there is a more annoying issue, as the device doesn't even have a ROMBAR, in this case, the VBIOS is likely in the VFCT ACPI table of host (which the guest can't see); which needs to be injected as a "fake" rombar for the guest to behave properly.

That doable on its own, but it's quite tricky to integrate (and you would e.g need to extract VBIOS from VFCT using external tools).

I just discussed with Xen/AMD people, and there are known issues regarding PCI Passthrough of integrated AMD GPUs (not specific to Xen AFAIU). There are some projects regarding alternative approaches to bring AMD GPUs to VMs (virtio-gpu native context) which is the current focus.

@DustyArmstrong said:

lspci -vvv -s 00:08.0

00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge
Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-

Ah that's not the one I'm looking for.

Can you do lspci -vvv (without the -s ...) and take the part related to the GPU ?

@DustyArmstrong
Can you give the result of :

lspci -vvv -s 00:08.0

(inside Dom0)

Another question, what guest were you trying ?
Can you try with a recent Linux kernel (some changes were made recently regarding video bios requirement) ? Latest Fedora should have a recent enough kernel for testing, that could maybe help workaround the issue in the meantime (and knowing if there are more issues), with no guarantee.

@benapetr said in New project - XenAdminQt - a cross-platform GNU/Linux, macOS, Windows native thick client:

@Pilow I know them a little bit, I will have a look, but I am now working on another new cool thing! It's called xen_exporter: https://github.com/benapetr/xen_exporter

It's a prometheus exporter that hooks directly to xen kernel via xenctrl library from dom0 and extract all low-level metrics from the host, allowing very detailed graphs with very low granularity with stuff I always missed in both XenOrchestra and XenAdmin:

...

We have a similar project : https://github.com/xcp-ng/xcp-metrics, but unfortunately it's not used as of today (though it could get revived as Rust for Xen matures, i.e easier to build).
There is also Xen Orchestra OpenMetrics support but it's not on XCP-ng itself.

@DustyArmstrong

EDIT: It looks like I may just have a fake BIOS? The settings to enable all the relevant components (IOMMU, DMAr support etc) don't actually seem to do anything, they might just be for show - dmesg | grep -i iommu returns nothing, dmesg | grep -i -e dmar -e vfio -e pciback only shows pciback info, and cat /proc/cmdline contains nothing about IOMMU. Oddly, XO is still reporting that IOMMU is enabled:

dmesg in the Dom0 will not report the information you're looking for.
To know if PCI Passthrough is supported (e.g IOMMU enabled), you should check xl info | grep virt_caps and look for hvm_directio. You can also look for IOMMU-related stuff in xl dmesg.
As you managed to passthrough the device (even if not working in the guest), I don't see a issue there.

[ 4.655776] amdgpu 0000:00:08.0: amdgpu: Unable to locate a BIOS ROM
[ 4.655797] amdgpu 0000:00:08.0: amdgpu: Fatal error during GPU init
[ 4.655812] amdgpu 0000:00:08.0: amdgpu: amdgpu: finishing device.
[ 4.656681] amdgpu 0000:00:08.0: probe with driver amdgpu failed with error -22

Is there a trick to this, has anyone had success with this kind of AMD GPU? On my old hosts, enabling pass through was enough for it to just kind of work (Intel HD 530). The host machine outputs to a display normally when the card is in-use by the host. I am of the understanding the ROM is just part of the motherboard/GPU, there is some suggestion it can be dumped from the host-side, but I'm unsure on this.

Looks like the GPU ROMBAR is missing in the guest, while it's ok for many devices, many others will fail to work without it (like this GPU).
To me, there's something missing on the PCI Passthrough logic, I just brought the topic internally to see what we can do.

@jbamford
Hello, can you give the output of xl info in Dom0 ? If you see hvm_directio in front of virt_caps, then PCI Passthrough is supported (i.e you have VT-d).

You can also check xl dmesg for vt-d specific messages (you can also give the output of it).

@EddieA Can you try differents combinations of passedthrough hardware in this VM ?

e.g try with each device one by one at a time; at least in the VM

@benapetr
Consider making a PR to https://github.com/xcp-ng/xcp-ng-org (https://github.com/xcp-ng/xcp-ng-org/blob/master/docs/management/management.md) if you want to make your project more visible.

@nvs can you try with a serial console and something listening on it; so when it crashes, we get the crash reason ?

@dcskinner @olivierlambert

You can read key/values from the xenstore, and write some (from VM to outside), but you cannot write values "in live" from outside the VM to the inside.

It is, but XAPI doesn't provide a interface for it.

do the guest tools quiesce the filesystems before snapshotting?

Tools are aware of a snapshot so you don't have blocks in flight.

do the guest tools quiesce the filesystems before snapshotting?

Guests kernel are aware, as it is them that are performing a "suspend" on toolstack request (thus quiece filesystems); although "tools" can only observe that the system has been suspended after the fact by measuring side effects, and not orchestrate it.

It's because suspend/resume operation doesn't come from "guest tools" actually, but instead from the kernel drivers. So userland tools has no say on it.