Remote desktop on Gnome hangs randomly

[ovicz]

Hello. I'm running a Rocky Linux 10 vm on xcp-ng latest version with gpu passthrough enabled. The host is a TOPTON mini-pc with intel Alder Lake N100 processor.

The problem is that at random times the RDP session freezes and to make it work again I have to restart the vm. The VM is running with no issues when this occurs but only the gui is not working. If I run with software rendering there are no problems at all, but that's not ideal.

The passthrough drivers are loaded correctly but something is not right.

lspci
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II]
00:01.2 USB controller: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] (rev 01)
00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03)
00:02.0 VGA compatible controller: Device 1234:1111 (rev 02)
00:03.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01)
00:08.0 Audio device: Intel Corporation Alder Lake-N PCH High Definition Audio Controller
00:09.0 VGA compatible controller: Intel Corporation Alder Lake-N [UHD Graphics]

lsmod | grep i915
i915 4677632 28
cec 69632 2 xe,i915
intel_gtt 24576 1 i915
drm_buddy 28672 2 xe,i915
i2c_algo_bit 20480 2 xe,i915
drm_display_helper 286720 2 xe,i915
video 81920 2 xe,i915
ttm 110592 4 drm_vram_helper,drm_ttm_helper,xe,i915

I've tried even with a newer distro as Debian Testing but it's the same result.

[ovicz]

If I pass the option GRUB_CMDLINE_LINUX_DEFAULT="i915.enable_guc=0 quiet" the gui doesn't freeze totally but still lags.

[ph7]

@ovicz
Perhaps upgrade bios ???

[ovicz]

I'm afraid there aren't any bios updates...the device is a chinese mini pc from aliexpress. I've spoken with the seller and he told there aren't any, at least not official ones. I don't think it's a bios issue, but something regarding the passthrough on the newer devices . maybe the kernel from xcp is too old, although it's heavily patched.

[ovicz]

Setting pci=nomsi seems to do the trick for now. Probably not optimal but it's just a VM and I didn't notice any performance issues.

[olivierlambert]

Adding @Team-OS-Platform-Release in case that rings a bell

[yann]

Since GPU passthrough is involved I'd ping @Team-Hypervisor-Kernel

[ovicz]

If i remove the pci=nomsi from grub..this pops up in xl dmesg.

(XEN) [15627.724045] CPU3: Running in modulated clock mode
(XEN) [15628.457337] d[IDLE]v0: Unsupported MSI delivery mode 7 for Dom5
(XEN) [15628.457339] d[IDLE]v2: Unsupported MSI delivery mode 7 for Dom5

That's when the gnome desktop hangs. Is this fixable ?

[dinhngtu]

@ovicz Are you up for a test package with a fix? Note that the fix is not yet tested nor supported at the moment.

Add user repos using this command:

yum-config-manager --add-repo https://koji.xcp-ng.org/repos/user/8/8.3/xcpng-users.repo

To know what you need to upgrade, run this command (as xcp-ng-ndinh2 contains some changes that you don't need):

rpm -qa --qf '%{NAME}\t%{SOURCERPM}\n' | grep $'\txapi'

Then upgrade just the XAPI-related packages:

yum update --enablerepo=xcp-ng-ndinh2 <list of packages from above>

Remember to reboot the host after installing.

Finally, disable hvm-pirq on your affected VM and reboot it (parameter name subject to change):

xe vm-param-set uuid=... platform:hvm-pirq=false

To go back, list what you installed and downgrade them:

yum list installed | grep ndinh
yum downgrade ...

[ovicz]

Hello. I did what you said and it seems to work. Thank you.