* Avi Kivity<avi@xxxxxxxxxx> wrote:
Which has pretty much the same problems to the ${HOME}/.qemu/qmp/ solution,Lets look at the ${HOME}/.qemu/qmp/ enumeration method suggested byI don't like it either. We have libvirt for enumerating guests.
Anthony. There's numerous ways that this can break:
obviously.
So out of a list of 4 disadvantages your reply is that you agree with 3?- Those special files can get corrupted, mis-setup, get out of sync, or can- it doesn't work with nfs.
be hard to discover.
- The ${HOME}/.qemu/qmp/ solution suggested by Anthony has a very obvious
design flaw: it is per user. When i'm root i'd like to query _all_ current
guest images, not just the ones started by root. A system might not even
have a notion of '${HOME}'.
- Apps might start KVM vcpu instances without adhering to the
${HOME}/.qemu/qmp/ access method.
Erm, but i'm talking about a dead tool here. There's a world of a difference- There is no guarantee for the Qemu process to reply to a request - whileIf qemu doesn't reply, your guest is dead anyway.
the kernel can always guarantee an enumeration result. I dont want 'perf
kvm' to hang or misbehave just because Qemu has hung.
between 'kvm top' not showing new entries (because the guest is dead), and
'perf kvm top' hanging due to Qemu hanging.
So it's essentially 4 our of 4. Yet your reply isnt "Ingo you are right" but
"hey, too bad" ?
We dont do that for robust system instrumentation, for heaven's sake!Really, for such reasons user-space is pretty poor at doing system-wideTake a look at your desktop, userspace is doing all of that everywhere, from
enumeration and resource management. Microkernels lost for a reason.
enumerating users and groups, to deciding how your disks are named. The
kernel only provides the bare facilities.
By your argument it would be perfectly fine to implement /proc purely via
user-space, correct?
Really, this is getting outright ridiculous. You agree with me that AnothonyYou are committing several grave design mistakes here.I am committing on the shoulders of giants.
suggested a technically inferior solution, yet you even seem to be proud of it
and are joking about it?
Really, for such reasons user-space is pretty poor at doing system-wide
enumeration and resource management. Microkernels lost for a reason.
And _you_ are complaining about lkml-style hard-talk discussions?