Date: Mon, 18 Mar 2013 13:35:55 +0100 From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= <roger.pau@citrix.com> To: "freebsd-xen@freebsd.org" <freebsd-xen@freebsd.org> Cc: dfr@FreeBSD.org, gibbs@FreeBSD.org, freebsd-virtualization@freebsd.org Subject: Difference in event channel implementation for Xen PV vs HVM guests Message-ID: <51470A2B.5040609@citrix.com>
next in thread | raw e-mail | index | archive | help
Hello, While working on improving XENHVM (I've been looking at adding PV timers), I've realized that the event channel implementation in PV vs HVM mode differs greatly. Xen PV port uses sys/xen/evtchn/evtchn.c while Xen HVM uses sys/dev/xenpci/evtchn.c, and the Xen HVM implementation is greatly reduced (only contains the necessary functions to operate backends/frontends). To implement PV timers I need to expand the event channel interface for XENHVM, and I was wondering why FreeBSD choose to have two different implementations, the main difference between PV and HVM is the event callback, but I guess this can be abstracted between the two different implementations, and then everything else could be reused. Am I missing something obvious? Is there any known technical problem in modifying XENHVM to use the full event channel implementation present in sys/xen/evtchn/evtchn.c that prevented XENHVM from using it in the first place? (Sorry if I've Cc'ed someone not related) Thanks, Roger.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?51470A2B.5040609>