On Mon, Oct 23, 2017 at 04:08:22PM +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 <[email protected]> > Reported-by: Andre Przywara <[email protected]>
Reviewed-by: Christoffer Dall <[email protected]> > > --- > > need to be CC'ed stable > > v4 -> v5: > - check the condition before updating its->enabled and > fix its->cbaser && GITS_CBASER_VALID > > v3: creation > --- > virt/kvm/arm/vgic/vgic-its.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index b0ba80f..1eb355e 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -1466,6 +1466,16 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, > struct vgic_its *its, > { > mutex_lock(&its->cmd_lock); > > + /* > + * It is UNPREDICTABLE to enable the ITS if any of the CBASER or > + * device/collection BASER are invalid > + */ > + if (!its->enabled && (val & GITS_CTLR_ENABLE) && > + (!(its->baser_device_table & GITS_BASER_VALID) || > + !(its->baser_coll_table & GITS_BASER_VALID) || > + !(its->cbaser & GITS_CBASER_VALID))) > + goto out; > + > its->enabled = !!(val & GITS_CTLR_ENABLE); > > /* > @@ -1474,6 +1484,7 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, > struct vgic_its *its, > */ > vgic_its_process_commands(kvm, its); > > +out: > mutex_unlock(&its->cmd_lock); > } > > -- > 2.5.5 >
