----- Ursprüngliche Mail ----- > Von: "Johannes Berg" <johannes@xxxxxxxxxxxxxxxx> > An: "Richard Weinberger" <richard.weinberger@xxxxxxxxx>, "Hajime Tazaki" <thehajime@xxxxxxxxx> > CC: "linux-arch" <linux-arch@xxxxxxxxxxxxxxx>, "cem" <cem@xxxxxxxxxxx>, "tavi purdila" <tavi.purdila@xxxxxxxxx>, > "linux-um" <linux-um@xxxxxxxxxxxxxxxxxxx>, "retrage01" <retrage01@xxxxxxxxx>, linux-kernel-library@xxxxxxxxxxxxx, > "pscollins" <pscollins@xxxxxxxxxx>, "sigmaepsilon92" <sigmaepsilon92@xxxxxxxxx>, "liuyuan" <liuyuan@xxxxxxxxxx> > Gesendet: Dienstag, 26. November 2019 09:43:36 > Betreff: Re: [RFC v2 17/37] lkl tools: host lib: virtio devices > On Mon, 2019-11-25 at 23:07 +0100, Richard Weinberger wrote: >> On Fri, Nov 8, 2019 at 6:03 AM Hajime Tazaki <thehajime@xxxxxxxxx> wrote: >> > From: Octavian Purdila <tavi.purdila@xxxxxxxxx> >> > >> > Add helpers for implementing host virtio devices. It uses the memory >> > mapped I/O helpers to interact with the Linux MMIO virtio transport >> > driver and offers support to setup and add a new virtio device, >> > dispatch requests from the incoming queues as well as support for >> > completing requests. >> > >> > All added virtio devices are stored in lkl_virtio_devs as strings, per >> > the Linux MMIO virtio transport driver command line specification. >> >> Did you checkout arch/um/drivers/virtio_uml.c? >> Why is this driver needed? > > This isn't really a driver, this is virtio *device-side* code. Our > virtio_uml is *guest-side* code, and only speaks vhost-user. Sorry, bad wording from my side. I meant with "driver" a kernel component. > I'm not sure how MMIO devices could possibly work though, does LKL > intercept MMIO somehow? My point is that UML and LKL should try to do use the same concept/code regarding virtio. At the end of day both use virtual devices which use facilities from the host. If this is really not possible it needs a good explanation. Thanks, //richard
