Re: KVM Shared memory ivshmem enquiry

[Neville Clark <nev@zavalon.com>]

Hi Cam,

On Thu, 2010-03-18 at 11:17 -0600, Cam Macdonell wrote:

> 
> Can you expand on how it doesn't run?  I would suggest using the
> master branch and patching it with my patches.  As well as patching,
> you need to run with something like
> 
> -ivshmem 128,myshm
> 
> to actually create the shared memory device.

Just to be clear, I think I have successfully loaded the required module
into the guest, and it is only on the host that I am having trouble.

I am currently using virt-manager and distro KVM to get something up.
I am much happier with a GUI then command-line.

I had hoped that I would be able to patch or load a module into this
Ubuntu's KVM. Installing KVM from Ubuntu does NOT seems to change the
running Linux kernel 'uname -a' after install of KVM is
"Linux dingo3 2.6.31-20-generic #58-Ubuntu SMP Fri Mar 12 04:38:19 UTC
2010 x86_64 GNU/Linux"

What I have tried to do is build and install qemu-kvm from the git tree
*without* patches. And then run an already configured guest using
virt-manager. The result is that using the HEAD, after about 30 secs I
get a pop-up with 
"Error starting domain: monitor socket did not show up.: Connection
refused"
with details of:
"Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/engine.py", line 493, in
run_domain
    vm.startup()
  File "/usr/share/virt-manager/virtManager/domain.py", line 558, in
startup
    self.vm.create()
  File "/usr/lib/python2.6/dist-packages/libvirt.py", line 293, in
create
    if ret == -1: raise libvirtError ('virDomainCreate() failed',
dom=self)
libvirtError: monitor socket did not show up.: Connection refused"


after switching version qemu-kvm-0.11.0 and repeating above I get
immediate (no 30 sec delay) pop-up
"Error starting domain: internal error cannot parse QEMU version number
in 'QEMU PC emulator version 0.11.0 (kvm-devel), Copyright (c) 2003-2008
Fabrice Bellard'"
with details of:
"Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/engine.py", line 493, in
run_domain
    vm.startup()
  File "/usr/share/virt-manager/virtManager/domain.py", line 558, in
startup
    self.vm.create()
  File "/usr/lib/python2.6/dist-packages/libvirt.py", line 293, in
create
    if ret == -1: raise libvirtError ('virDomainCreate() failed',
dom=self)
libvirtError: internal error cannot parse QEMU version number in 'QEMU
PC emulator version 0.11.0 (kvm-devel), Copyright (c) 2003-2008 Fabrice
Bellard'"

Primary questions are: 
What is the simplest starting point to use your patches?
Is there a module for the HOST that can be loaded into a running KVM?
Do I need to build and install the Linux kernel from the KVM git tree?


> 
> > I have checked out the qemu-kvm-0.11.0 and built and installed but then
> > I get a version miss-match. (this was unpatched as the patch does not
> > work on this version).
> 
> shared memory requires a patched qemu-kvm at this point.
> 
> >
> > The host is Ubuntu 9.10 64 bit, with ubuntu's KVM installed.
> >
> > Can I simply somehow build and install ivshmem module, or do I need to
> > rebuild the kernel? eg get kvm.git and build and install new kernel.
> 
> You can just build the module.
Does this apply to both the guest and the host, or just the guest.
If this applies to host, where can I find the module?
> 
> > Is there another KVM binary that I can use, instead of Ubuntu's?
> 
> You can't use a distro binary as they don't support shared memory.
>