Date: Fri, 2 Mar 2018 07:11:26 -0800 (PST) From: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> To: Ludovit Koren <ludovit.koren@gmail.com> Cc: Andriy Gapon <avg@FreeBSD.org>, freebsd-virtualization@FreeBSD.org Subject: Re: bhyve - windows7 installation Message-ID: <201803021511.w22FBQbf030531@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <86woyvgd3v.fsf@gmail.com>
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> >>>>> Andriy Gapon <avg@FreeBSD.org> writes:
>
> > On 01/03/2018 16:06, Rodney W. Grimes wrote:
> >> Due to the design of the IOMMU you can only manage IO space in page
> >> (4096 on x86) granually sizes. The device your trying to pass in
> >> has a 1024 byte memory region that is part of a 4096 byte page that
> >> may have other things in it.
> >>
> >> At this time bhyve does not have any way to deal with this, though some
> >> other hypervisors have techniques that make this work.
> >>
> >> I do not have or know of any list of USB controller cards that
> >> have 4k aligned and 4k sized BAR's.
>
> > I have this local hack for that problem.
> > It comes without any warranty and its use is completely at your own risk.
>
> Thank you. I will try it.
Andriy,
Thanks for providing this patch, I tried to find the repository
it is in with google and did not, is this a private repository?
Either way would it be ok with you if I published, with attribution
of cource, your patch first from my people.freebsd.org/~rgrimes#bhyve
page, and possibly later from a wiki page? I'll properly dress it
in "this has security implications" and enumerate what those are.
Thanks,
> lk
>
> > commit 74e0a8d1ae01c7aaabd7d965958b735c7cf18871
> > Author: Andriy Gapon <avg@icyb.net.ua>
> > Date: Fri Nov 17 20:17:57 2017 +0200
>
> > bhyve: allow BAR sizes that are not page aligned by rounding them up
>
> > This is based on the assumption that drivers won't access the added space.
>
> > diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
> > index f314679d912b0..14c1384c6c8f8 100644
> > --- a/usr.sbin/bhyve/pci_passthru.c
> > +++ b/usr.sbin/bhyve/pci_passthru.c
> > @@ -563,13 +563,20 @@ cfginitbar(struct vmctx *ctx, struct passthru_softc *sc)
> > size = bar.pbi_length;
>
> > if (bartype != PCIBAR_IO) {
> > - if (((base | size) & PAGE_MASK) != 0) {
> > + if ((base & PAGE_MASK) != 0) {
> > warnx("passthru device %d/%d/%d BAR %d: "
> > - "base %#lx or size %#lx not page aligned\n",
> > + "base %#lx not page aligned\n",
> sc-> psc_sel.pc_bus, sc->psc_sel.pc_dev,
> > - sc->psc_sel.pc_func, i, base, size);
> > + sc->psc_sel.pc_func, i, base);
> > return (-1);
> > }
> > + if ((size & PAGE_MASK) != 0) {
> > + warnx("passthru device %d/%d/%d BAR %d: "
> > + "size %#lx not page aligned\n",
> > + sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
> > + sc->psc_sel.pc_func, i, size);
> > + size = round_page(size);
> > + }
> > }
>
> > /* Cache information about the "real" BAR */
>
>
> > --
> > Andriy Gapon
>
>
> --
> A: Because it fouls the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
Sorry for the middle posting :-)
> A: Top-posting.
> Q: What is the most annoying thing on usenet and in e-mail?
--
Rod Grimes rgrimes@freebsd.org
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