Re: [RFC] Unify KVM kernel-space and user-space code into a single project

Joerg Roedel
2010-03-24T15:59:27Z

On Wed, Mar 24, 2010 at 05:49:42PM +0200, Avi Kivity wrote:
> On 03/24/2010 05:46 PM, Joerg Roedel wrote:
>> On Wed, Mar 24, 2010 at 05:12:55PM +0200, Avi Kivity wrote:
>>
>>> On 03/24/2010 05:01 PM, Joerg Roedel wrote:
>>>
>>>> $ cd /sys/kvm/guest0
>>>> $ ls -l
>>>> -r-------- 1 root root 0 2009-08-17 12:05 name
>>>> dr-x------ 1 root root 0 2009-08-17 12:05 fs
>>>> $ cat name
>>>> guest0
>>>> $ # ...
>>>>
>>>> The fs/ directory is used as the mount point for the guest root fs.
>>>>
>>> The problem is /sys/kvm, not /sys/kvm/fs.
>>>
>> I am not tied to /sys/kvm. We could also use /proc/<pid>/kvm/ for
>> example. This would keep anything in the process space (except for the
>> global list of VMs which we should have anyway).
>>
>
> How about ~/.qemu/guests/$pid?

That makes it hard for perf to find it and even harder to get a list of
all VMs. With /proc/<pid>/kvm/guest we could symlink all guest
directories to /proc/kvm/ and perf reads the list from there. Also perf
can easily derive the directory for a guest from its pid.
Last but not least its kernel-created and thus independent from the
userspace part being used.

Joerg