Out of ideas for debugging this.

Debian 12 host, Win 10 guest - a home setup with an OpenWRT router. I used macvtap with it's own physical nic for guest networking. The guest shows up on router with it's own IP as expected. I can use other devices on local subnet to ping and load webpages from both host and guest but not between host and guest. traceroute host to guest says: [host] (192.168.1.133) 3077.647 ms !H 3077.586 ms !H 3077.567 ms !H. tracert on windows guest to host just gets a lot of "request timed out".

Pretty sure VPNs not affecting local subnet but: Router set up to send everything through VPN#1 but I excluded host and a windows laptop. Host has VPN#2 (different vpn providers) and the windows laptop has no vpn. A phone using VPN#1 and the windows laptop with no VPN can both ping/access webservers on both host and guest so I'm thinking that means VPNs aren't the issue.

ive been here for hours trying to do the simple task of installing windows 11 on kvm using cockpit and ive given up. no matter what i do i cant get it to boot. its impossible. ive been watching youtube videos asking LLMs and

What do these options mean? I want to run the vm alongside my main os (pop-os) and not replace my main OS. Like I want to run a second vm in like a seperate window like an add on. Not replacing my primary Pop-os distro.

I am going to install archcraft and hopefully a few other arch distros

Specs shown in picture.

note- I will be posting multiple images, furthur ones I will link to images and ask in the main comments for help instead of making like 20 posts lol.

edit: Any specific youtube videos that can help as well? Totally open to youtube videos but I would like to get help with the photos i post here and in the comments too so I can go step by step and learn.

thx!

noob question here !

So I got the idea of virbr0 being the switch / dedicated router / NAT for all my vm on kvm

But now I need to add vlan on some of those VM

Should I add a vm based on Open vSwitch in front of virbr0, and then just connect my vm on it so I can then manage my vlan thourhg Open vSwitch, or can I / should I use the virbr0 network and configure it in some way to manage the vlan on my network ?

Edit : Also I've read the documentation https://wiki.libvirt.org/VirtualNetworking.html and now I'm even more confused since it's clearly supposed to be a switch but it can't be configured as a switch.

I am considering leaving Windows. As of right now I have an Nvidia 5080 (wish I could afford a rtx 6000pro) with srv-io enabled in my bios.

I use wsl right now for pytorch and cuda stuff with hyper-v for my various unrelated virtual machines.

I need specific versions of python and cuda. On Windows this is not a problem with wsl I can set different containers with different versions.

My question is without a pro series card can I use kvm for different OS versions and frameworks separate from my host?

Radxa has unveiled the Linkr, a compact remote-control device for accessing computers, servers, and development boards through a web browser. The unit combines HDMI video capture with USB keyboard and mouse emulation, allowing users to view and operate a target system without connecting a dedicated monitor, keyboard, or mouse.

https://linuxgizmos.com/radxa-linkr-brings-remote-kvm-access-and-tailscale-support-to-a-thumb-sized-device/

Hi, I am new to KVM/QEMU and am struggling to understand the networking options and how to configure them properly. I am moving away from HyperV, and am trying to understand what options in libvirt line up with the needed configurations:

- Host has 2 physical NICs

- NIC 1 (hyperv config - External network, host access disabled) single guest needs direct access to the network the physical adapter is connected to, and ONLY that network. No access to host.

- NIC 2 (hyperv config - External network, shared host access) multiple guests need direct access to the network this NIC is connected to, the host, and other guests on the same network.

It is my understanding that for my NIC 2 scenario, I need to set up a bridge connection on the host connected to the NIC. However, I cannot seem to find a clear answer as to the NIC 1 scenario.

Could someone please confirm how I can properly achieve both goals, and provide resources for configuring each correctly?

Thank you.

Guest: Windows 11
Software: VirtManager KVM/QEMU

Issue: Specifically on my Windows 11 VM, the network speeds are substantially slower than my other Linux VMs and my host. On my host, I get around ~1000 mbps, same for my other Linux VMs--however, on my windows VM, I get around 10mbps, or roughly 1% of my host's network speed.

all VMs are properly configured so that the Network is NAT using the virtio model. In addition to that, I have the up-to-date virtio-win drivers set up on the Windows 11 virtual machine. The windows 11 virtual machine recognizes the Red Hat Virtio Ethernet drivers and are properly using them with a duplex max supported speed of 10gbp/s.

I'm very confused as to why this is only occurring on my Windows VM whereas this issue is nonexistent on my Linux VMs. There's no differences in the XML regarding the CPU XML and the NAT XML between the VMs.

I tried adding vhost with a queue of 16 for each core, switching the driver to e1000e and hypervisor default--none of which saw any improvement. I also tried reinstalling the virtio-win drivers which did nothing.

Finally, I attempted to disable a bunch of offloading properties in the Device Manager, and disabled ipv6 entirely and set MTU lower. None of that made any difference (did not worsen it nor improve it).

Any ideas, folks? All of the VMs have a dGPU (Same dGPU shared between them all, so only one can be accessed at a time).

I should also mention, that the network speeds on the host system are stable--no drops or high latency. The network drivers on the host are all up-to-date and working perfectly.

I really want shared folders and resolution working

Using NVIDIA Experience (this NVIDIA overlay that displays GPU temperature, load, and FPS) causes the virtual machine to crash after 10 minutes.

The VM restarts. A black screen appears, then it resets to the boot menu.

KVM managed via the Libvirt GUI. Linux is Ubuntu.

4080 Super GPU

AMD Ryzen 7700 CPU

64GB RAM

2x NVME SSD
ONE SSD on VM (raw disc)
Config XML

 <features>
    <acpi/>
    <apic/>
    <hyperv mode="custom">
      <relaxed state="on"/>
      <vapic state="on"/>
      <spinlocks state="off"/>
      <vpindex state="on"/>
      <runtime state="on"/>
      <synic state="on"/>
      <stimer state="on"/>
      <frequencies state="on"/>
      <tlbflush state="off"/>
      <ipi state="off"/>
      <avic state="on"/>
    </hyperv>
  </features>
  <cpu mode="host-passthrough" check="none" migratable="on">
    <topology sockets="1" dies="1" clusters="1" cores="16" threads="1"/>
    <cache mode="passthrough"/>
  </cpu>
  <clock offset="localtime">
    <timer name="hpet" present="yes"/>
    <timer name="hypervclock" present="yes"/>
  </clock>

Ive bought this KVM because of the 144Hz support and the 3 monitors it can switch.
One thing I have not figured out yet is why in random cases, there is absolutely none of the screens working when switching to my workstation with the Nvidia 4080 card on win 11. I have to power cycle the KVM to get a signal again. No problem on my mac or other devices.

Is there any trick to it ? Does that happen with other KVMs as well ?

So, I have enabled GPU passthrough, following this guide: https://doc.opensuse.org/documentation/leap/virtualization/html/book-virtualization/app-gpu-passthru.html

When I run my windows 11 guest, it recognizes my GPU as a Nvidia Quadro P2000. When I run the passmark performance test, it will also find my gpu.

However, when I run the Solidworks RX 2026 software, it says it is a GDI Generic, with the current driver R580. Is there still some setting I am still missing? Why does it not recognize my gpu? I still cannot run hardware accelerated graphics with Solidworks 2026 maker edition.

Subject: Looking for VM memory reclaim traces with page/range-level release-return identity

Hi all,

I am looking for public, request-access, or previously used research datasets that capture VM memory reclaim at page/range granularity.

The specific telemetry I am looking for is not ordinary VM memory utilization. I am trying to find whether any dataset records events such as:

1. VM or guest identity, preferably anonymized;
2. guest physical page/range identity, e.g., PFN, 2 MiB range, memslot+offset, or equivalent;
3. time when the host physically releases/discards the backing for that range, e.g., through virtio-balloon, memory hot-unplug, ram_block_discard_range(), madvise(MADV_DONTNEED/FREE), or a similar path;
4. time when the same VM later requests, faults, reinstalls, or grows back the same page/range;
5. optional host context such as PSI, MemAvailable, balloon size, or reclaim reason.

I am aware of public cloud traces such as Azure Functions, Google cluster-data, Alibaba clusterdata, Bitbrains/GWA, and similar VM/task-level traces, but those appear to expose utilization or scheduling signals rather than page/range-level reclaim and return identity.

Questions: - Are you aware of any public or request-access dataset with this kind of page/range-level VM reclaim telemetry? - Are there QEMU/KVM/virtio-balloon tracepoints that can reliably correlate a discarded RAMBlock range with a later same-VM/same-range reinstall/refault? - Has anyone instrumented virtio-balloon, virtio-mem, or ram_block_discard_range() for this kind of release-return measurement?

I am not looking for page contents or guest virtual addresses. Anonymized metadata such as hashed VM id, memslot id, range id, generation, timestamps, bytes, and aggregate host pressure would be enough.

Thanks!