Port-xen archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: /kern/xen in domU?

On Wed, 21 Sep 2011 12:33:18 +0100 (BST), Stephen Borrill wrote:
On a NetBSD guest, I installed xentools33 to give me the relevant
xenstore tools and libraries, but /kern/xen doesn't exist on NetBSD as
a domU. Indeed, xenbus_probe_init() explicitly skips setting it up
unless DOM0OPS is set.

Any reason for this restriction?

No restriction, a domain should be able to use Xen tools to write information in its own subtree inside XenStore.

Explanations why it isn't:

IIRC about a year ago Andrew disabled kernfs because it would disappear eventually, replaced by a mix of sysctls, kvm(3) and /dev nodes. Unfortunately, there are entries required by dom0 to send or query information from Xen, created dynamically under /kern/xen.

As the current Xen tools do not have compat code to handle kernfs' disappearance, it stayed in but was not exposed to a wider audience (domUs). Retiring kernfs touches multiple parts, and will require compat code in Xen tools + modifying NetBSD, so unless this gets done for -6, it will be around for some time.

Jean-Yves Migeon

Home | Main Index | Thread Index | Old Index