I am setting KVM Nested Virtualization for my AMD bare metal CPU. I see there are both kvm-amd and kvm_amd description in guides (search /etc/modprobe.d on pages): - https://linux-kvm.org/page/Nested_Guests - https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/8/html/configuring_and_managing_virtualization/creating-nested-virtual-machines_configuring-and-managing-virtualization#creating-a-nested-virtual-machine-on-amd_creating-nested-virtual-machines - https://docs.fedoraproject.org/en-US/quick-docs/using-nested-virtualization-in-kvm/ - https://www.kernel.org/doc/html/v5.9/virt/kvm/running-nested-guests.html - https://ubuntu.com/server/docs/how-to-enable-nested-virtualization Which word is correct here? options kvm-amd nested=1 or options kvm_amd nested=1

I want to create a nested virtual machine with network access. I use vagrant on the Host (Layer 0) to create the Layer 1 guest, and then would want to use vagrant to create a Layer 2 guest (inside the Layer 1). However, when I try to create the Layer 2 machine, vagrant up fails with:

Error while activating network: Call to virNetworkCreate failed: internal error: Network is already in use by interface eth0.

I think I added a second NIC to the Layer 1 so that it can use it for the Layer 2 but I am unsure. I am a little new to VM nesting, so am not sure how to resolve this. Here is my config: ##### Host Vagrantfile

ENV["VAGRANT_DEFAULT_PROVIDER"] = "libvirt"

Vagrant.configure("2") do |config|
  config.vm.define "u22" do |ubuntu|
    ubuntu.vm.box = "generic/ubuntu2204"
    # Tests:
    # ubuntu.vm.network "public_network", :dev => "wlp3s0"
    # ubuntu.vm.network "private_network", dhcp: true
    ubuntu.vm.network "private_network", ip: "10.10.10.30"
  end
end

##### Guest Vagrantfile

ENV["VAGRANT_DEFAULT_PROVIDER"] = "libvirt"

Vagrant.configure("2") do |config|
  config.vm.box = "centos/stream8"
end

The host is an Ubuntu 20.04. Not sure if this is enough info (please ask away, I'm a noobie).

I have a baremetal server with Debian. Iside it I have KVM-based VMs and LXC containers. Now I am searching a solution to run KVM inside LXC container.

Im thinking how to make things easier, namely I would like to know if there is any possibility to make i.e rhel8.iso attached to VMware Workstation available to guest OS inside. I want use kvm inside guest OS (RHEL 8). I know about solution like i.e dd if=/dev/sr0 of=./rhel.iso and then using it as iso image, however it is doubled work. Thanks in advance!

I have a Ubuntu 16.04 VPS right now. The hostisng provider uses KVM for virtualization of their VPS'. I am trying to install another KVM virtual machine on my VPS (aka nested KVMs). I've read this short guide for how to enable it: https://www.linux-kvm.org/page/Nested_Guests Apparently all I need to do to enable nested KVM instances is apply this flag at bootup of my purchased VPS: > -cpu host So my question is, how can I set a bootup flag? Edit a config file for the bootup related stuff, or pass a parameter to the reboot command?

I have laptop with 16GB RAM, trying to install Red Hat Enterprise Virtualization Hypervisor 3.3 on Virtual Machine Manager (KVM) based guest, but it gives error "Virtualization Hardware not found". What's possible solution for this error? Like in OracleVM box there is a option to enable support for Virtualization for guest machine? Is there anything like same in Virtual Machine Manager? Is it possible to test RHEV 3.3 on any of the virtualization like KVM, OracleVM box or VMWare Workstation 10?

I want to deploy openstack with nested virtualization enabled. Here is the scenario, on physical machine (Ubuntu 16.04) I have 2 VMs running, 1. kvm01 and, 2. cmp001 Kvm01: has 7 VMs up and running with different openstack services, with 68 vcpus. Cmp001: has nova-compute running with 8 vcpus. I have deployed the openstack successfully on nested VM environment, but VM inside kvm01 slows down after approx. 12 hours and I need to destroy all the vms with virah destroy and destroy kvm01 itself and start again and then everything works fine again. I don't know what is the problem there and why VMs inside KVM01 are getting slow after some time. I am using Ubuntu 16.04 OS on physical machine, have 128 GB of RAM and 48 physical cores with 2 NUMA node, I have tried CPU pinning for kvm01 (pinned 42 physical CPUs to the kvm01 vm) but that didn't work for me. Note: Current CPU model for kmv01 and cmp001 is host-passthrough, I have tried host-model which didn't work for me. Hope this is clear. Please let me know in comment if XML file of kvm01 or cmp001 is required, or any other information required. Thanks in advance.

Morning all I'm currently trying to set-up a Nested CentOS 7.0 KVM host inside a vSphere ESX 5.1.0 hypervisor. I've been following http://virtuallyhyper.com/2012/07/installing-kvm-as-a-virtual-machine-on-esxi5-with-bridged-networking/ I've managed to get the KVM Host installed successfully, and it's configured to support KVM and libvirt. However the issue comes in when I try and pxeboot a KVM Guest against my existing DHCP server. I can see a DHCPDISCOVER being issued by iPxe, and the DHCP server logs a DHCPOFFER, but it never receives a DHCPREQUEST from iPxe on the kvm-guest. I've setup the KVM host with a bridged network, and disabled the 'default' NAT network: [root@kvm-test ~]# brctl show bridge name bridge id STP enabled interfaces br0 8000.005056970ea0 yes ens160 vnet0 [root@kvm-test ~]# ifconfig br0: flags=4163 mtu 1500 inet 192.168.18.51 netmask 255.255.255.0 broadcast 192.168.18.255 inet6 fe80::250:56ff:fe97:ea0 prefixlen 64 scopeid 0x20 ether 00:50:56:97:0e:a0 txqueuelen 0 (Ethernet) RX packets 105230 bytes 13897310 (13.2 MiB) RX errors 0 dropped 11 overruns 0 frame 0 TX packets 105566 bytes 44412894 (42.3 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ens160: flags=4163 mtu 1500 inet6 fe80::250:56ff:fe97:ea0 prefixlen 64 scopeid 0x20 ether 00:50:56:97:0e:a0 txqueuelen 1000 (Ethernet) RX packets 105378 bytes 15365254 (14.6 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 106773 bytes 44491366 (42.4 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73 mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 0 (Local Loopback) RX packets 217153 bytes 54126840 (51.6 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 217153 bytes 54126840 (51.6 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 vnet0: flags=4163 mtu 1500 inet6 fe80::fc54:ff:fec1:978 prefixlen 64 scopeid 0x20 ether fe:54:00:c1:09:78 txqueuelen 500 (Ethernet) RX packets 40 bytes 17480 (17.0 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 743 bytes 48921 (47.7 KiB) TX errors 0 dropped 755 overruns 0 carrier 0 collisions 0 The guest is configured with a 'bridged' interface: [root@kvm-test ~]# virsh edit 2 kvm-guest.test.card.co.uk 82c15c03-aec5-4dd9-ad23-67275f742c89 ... iptables is disabled on the KVM host, and there's no local dhcp server running. Any ideas on what the issue could be? Cheers Gavin

# Summary # I'm currently training for RHCSA. I have to install few servers with KVM. I'm unable to select the DVD drive to install the OS (greyed out). While I can install by other means, I'm curious to know why I can't this way. # My setup # That's the tricky part. My KVM host is a VMware Workstation guest. The DVD is correctly mounted in OS, I can browse it from GUI and CLI. # Question # Why am I unable to chose DVD Drive ? Is it because of the nested Virtualization ? Is it some security setting in KVM ?

I'm new to Linux. I'm trying to build Chromium OS and run it on QEMU. Meanwhile I came across Linux KVM, Virtualbox and VMWare. So I have basically two questions about virtualization in Linux: 1. What are the top popular open source virtualization systems that are used in the industry today? Do I have more choices for example when running another distro on top of my Ubuntu box? 2. If someone has experience with virtualization in Linux would you please share some hints when to use what? Which ones are used to set up a cloud?

While installing RHEV Hypervisor 3.3 on Oracle VirtualBox I am getting following message: Failed to open a session for the virtual machine RhevH1 VT-x is used by another hypervisor. (VERR_VMX__IN_VMX_ROOT_MODE). VirtualBox Can't operate in VMX root mode. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_VMX_IN_VMX_ROOT_MODE). What are the possible solutions are there for this?