Re: Instability issues with NetBSD-9, xen-4.11 and the xbdb backend driver

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Fri, Nov 01, 2019 at 10:25:16AM -0700, Brian Buhrow wrote:
> 	hello.  Further investigation into this issue seems to suggest there
> is some sort of memory corruption going on  on the xen ring.  I'm seeing
> further messages about shared memory errors from the bdback_xenbus driver.
> Further, once the problem occurs, subsequent restarts of that domu fail
> rapidly with similar errors.
> 	Given the fact that I'm seeing biodone2 errors on the domu guests, this
> really looks like some sort of race condition.  here are some questions:
> 
> 1.  When a guest passes a request back to the xbdback_xenbus driver, is it
> expected that all requests will be fulfilled in the order in which they
> were received?  I'm assuming yes, otherwise, the guest couldn't be assured
> of the order of filesystem operations.  
> 
> 2.  Which process is it at manages the xenbus between the dom0 host and
> domu guests?
> 
> 	Is anyone else running xen-4.11 with NetBSD-9?

I've done some light tests and didn't notice issues.
Is it a sotck XEN3_DOM0 kernel or some custom ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--