On Tue, Oct 17, 2017 at 09:10:02AM +0200, Eric Auger wrote: > The spec says it is UNPREDICTABLE to enable the ITS > if any of the following conditions are true: > > - GITS_CBASER.Valid == 0. > - GITS_BASER<n>.Valid == 0, for any GITS_BASER<n> register > where the Type field indicates Device. > - GITS_BASER<n>.Valid == 0, for any GITS_BASER<n> register > where the Type field indicates Interrupt Collection and > GITS_TYPER.HCC == 0. > > In that case, let's keep the ITS disabled. > > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> > Reported-by: Andre Przywara <andre.przywara@xxxxxxx> > > --- > > v3: creation > --- > virt/kvm/arm/vgic/vgic-its.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index e59363e..e61736b 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -1488,6 +1488,16 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, struct vgic_its *its, > its->enabled = !!(val & GITS_CTLR_ENABLE); > > /* > + * It is UNPREDICTABLE to enable the ITS if any of the CBASER or > + * device/collection BASER are invalid > + */ > + if (its->enabled && > + (!(its->baser_device_table & GITS_BASER_VALID) || > + !(its->baser_coll_table & GITS_BASER_VALID) || > + !(its->cbaser && GITS_CBASER_VALID))) > + its->enabled = false; > + uh, why don't we check these conditions before we enable the ITS instead of enabling, checking, and then disabling? Thanks, -Christoffer > + /* > * Try to process any pending commands. This function bails out early > * if the ITS is disabled or no commands have been queued. > */ > -- > 2.5.5 >
