I read from here that vmx capability support on QEMU must be explicitly enabled by providing the +vmx option to the command but the problem is that it does not seem to work. In my system, the VMX feature is still undetected.
Command:
qemu-system-x86_64 -no-kvm -cpu qemu64,+vmx,-svm ...
In my guest OS, when I execute cpuid 1 I get ECX = 0x80802001; bit 5 = 0 meaning that my virtual CPU does not have VMX.
Is this a bug?
Or is there another way to enable the vmx feature in QEMU?
No, the vmx flag is not supported in the processor emulation mode of QEMU. In order to use vmx in QEMU, you must use KVM with QEMU (replacing -no-kvm with -enable-kvm); and your host processor must support vmx.
In this document it shows the nested vmx instructions support in the Linux KVM; meaning this feature must be used with -enable-kvm.
In my test the options -enable-kvm -cpu kvm64,+vmx work, as the vmx feature is detected in the guest OS.
The following command works for me:
qemu-system-x86_64 -cpu host -kernel kernel/kernel -serial stdio -enable-kvm
-cpu host makes QEMU report host CPU features inside the VM (so your CPU must support vmx)
-enable-kvm is required by -cpu host
Even though according to this -cpu qemu64,+vmx should work, it doesn't work for me either.
Related
Can anyone help me on how to boot QEMU KVM with libvirt/sVirt but without using virt-install tool in command line.
or using virsh tool
In order to use virt-install, you need to install the following:
yum install qemu-kvm qemu-img libvirt libvirt-python libvirt-client virt-install virt-viewer bridge-utils tigervnc-server
Then, you can start the daemon:
systemctl start libvirtd
Now, download the OS you want to install, and then copy it to the folder shown below:
cp CentOS-7-x86_64-Everything-1708.iso /var/lib/libvirt/images/
Finally, run virt-install. Here is an example of what the script should look like:
os="--os-type=linux --os-
variant=centos7.0"
location="--location=/var/lib/libvirt/images/CentOS-7-x86_64-Everything-1708.iso"
cpu="--vcpus 2"
ram="--ram 2048"
name="centos7"
disk="--disk /dev/mapper/centos_192- root,size=40"
type="--virt-type qemu"
network="--network network=default"
graphics="--graphics none"
virt-install $os $network $disk $location $cpu $ram $type $disk $graphics --name=$name
After running virt-install, verify that the VM is running using virsh:
virsh list
Id Name State
----------------------------------------------------
4 centos7 running
Virt-install command-line options
Below are some command-line options, but this isn't an extensive list, so I encourage you to do some research in order to fully take advantage of this tool.
os="--os-type=linux --os-variant=centos7.0" --
Some of these commands have main options, as well as sub options. For example, if you type os-type=linux, then you need to further specify --os-variant=centos7.0. You can get a list of OSes that virt-install supports by typing osinfo-query os.
location="--location=/var/lib/libvirt/images/CentOS-7-x86_64-Everything-1708.iso"
This is where you've copied the ISO image file containing the OS you want to install.
cpu="--vcpus 2"
The CPU command-line option enables you to specify the number of vCPUs assigned to the VM. In this example, I'm assigning two vCPUs.
ram="--ram 2048"
The RAM command-line option enables you to specify the amount of memory assigned to the VM. In this example, I'm assigning 2,048 MBs -- or 2 GBs.
name="centos7"
The name command-line option enables you to assign a name to the VM. In this example, I'm naming the VM centos7.
disk="--disk /dev/mapper/centos_192-root,size=40"
This is where the VM will be installed and the size, in gigabytes, to be allocated. This must be a disk partition and not a mount point. Type df -h to list disk partitions.
type="--virt-type qemu"
The type command-line enables you to choose the type of VM you want to install. You can use KVM, QEMU, Xen or KQEMU. Type virsh capabilities to list all of the options. In this example, I'm using QEMU.
network="--network network=default"
Use network=default to set up bridge networking using the default bridge device. This is the easiest method, but there are other options.
graphics="--graphics none"
The graphics command-line option specifies that no graphical VNC or SPICE interface should be created. Use this for a kickstart installation or if you want to use a ttyS0 serial connection.
I am following the steps given here.
The page asks to set options in qemu for using usbredir.
When I install qemu on fedora there are bunch of qemu related commands like
qemu-alpha qemu-ppc qemu-system-mipsel
but not a command qemu itself.I do have the Virtual Machine Manager which shows up QEMU/KVM and some xml in the details of the same.
How to configure the options in qemu?
I have no previous knowledge of how to configure an option in qemu.
I have a OVA file(MyOvafile.ova) which contain MemorySize=16GB and CPU count=4.
I have deployed the Ovftool on VMware ESXi server.
I am using the following command to deploy the VM:
/vmfs/volumes/DataStore1/vmware-ovftool/ovftool --memorySize:15360 --name=Test_VM -dm=thin -ds=DataStore1 /vmfs/volumes/DataStore1/OVA_V5.1_BSI-8/MyOvafile.ova
Now the problem i am facing:
As i am giving MemorySize of 15360MB but after deployment VM has the same values as defined in ova file (MyOvafile.ova i.e 16GB)
My Question:
How can i change the value of MemorySize and CPU count through ovftool command?
Apparently, this seems a bug in OVFTOOL (and documentation as well).
CPU and memory cannot be overridden by OVFTOOL's corresponding parameters.
However, there is hack by modifying it in VMX file of VM (and then using reconfigure command).
1) Get VMXfile Location (ending with .vmx) :
vim-cmd vmsvc/getallvms
Vmid Name File Guest OS Version Annotation
72 Test_vm [datastore2] VM_name/VM_name.vmx rhel6_64Guest vmx-08
2) Modify vmx file (for example, using awk) for changing 'vCPUS=REQ_CPUs' entry.
3) Reconfigure .vmx file
vim-cmd vmsvc/reload <VM_ID>
Issue reported in VMware community: https://communities.vmware.com/message/2698710#2698710
Im running ubuntu 14.04 with vbox . In this machine I compiled and run kernel 3.14 which I choose from the grub menu when ubuntu load on vbox.
The host also run on ubuntu 14.04.
I wanted to ask - is there a way to load the guest ubuntu into specific kernel with a command on shell?
I can start running a vm on vbox trough command line with this command :
VBoxManage startvm ubuservloc --type headless
but its not quite exactly what I need.
I don't know of any way to directly communicate from the host to the guest's GRUB, but there are several indirect ways you could go:
mount the /boot filesystem from the host and drop a file there that is read by the guest's grub.cfg.
VBoxManage controlvm keyboardputscancode to type a hotkey which is assigned to the correct kernel in GRUB (shortly after starting the VM)
Configure GRUB to listen to a (virtual) serial port and select the kernel by writing to that file
In case a second reboot is acceptable (first boot into default kernel and then reboot into desired kernel) there are also several ways (you can use the grub-set-default command from guest to choose your desired kernel and issue a reboot). Some I can think of here:
VBoxManage guestcontrol run to call a shell script from host in the guest (after guest additions have been loaded)
VBoxManage guestproperty to set a property from host and VBoxControl guestproperty to read it from an init script and decide from there
Just SSH into the guest and reboot from there :D
Obviously, if you always want to boot that kernel, why not make it default? And in case always you want to alternately boot two different kernels, you can also set the default for next boot to another one direclty from grub.cfg.
I've used buildroot to compile a firmware targetting the LPC EA3250 board, I'm trying to get this to run using qemu so that I can test changes to the firmware on my machine. I've tried commands such as:
qemu-system-arm -M virt -kernel uImage -hda rootfs.ext2 -boot c -m 128M -append "root=/dev/sda rw console=ttyS0,38400n8"
But I keep getting similar errors no matter which -M option I apply. It seems that somehow I need to get a new machine option to pass qemu which will correspond to my board. I've found this config file which seems to be the configuration needed for the board I'm looking at.
What I would like to know is how to insert this config into qemu. Do I have to place this config somewhere and then recompile everything? If I do where do I need to put it?
On further investigation it seems that the config file I found is for something else entirely. The LPC EA3250 is not supported by qemu and adding in support for additional machines is an extensive task.