From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH v5 03/10] KVM: arm/arm64: vgic-its: Check CBASER/BASER validity before enabling the ITS Date: Wed, 25 Oct 2017 13:52:22 +0200 Message-ID: <20171025115222.GG91785@lvm> References: <1508767709-15256-1-git-send-email-eric.auger@redhat.com> <1508767709-15256-4-git-send-email-eric.auger@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: eric.auger.pro@gmail.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com, peter.maydell@linaro.org, andre.przywara@arm.com, wanghaibin.wang@huawei.com, wu.wubin@huawei.com, drjones@redhat.com, wei@redhat.com To: Eric Auger Return-path: Received: from mail-wr0-f193.google.com ([209.85.128.193]:50365 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbdJYLwZ (ORCPT ); Wed, 25 Oct 2017 07:52:25 -0400 Received: by mail-wr0-f193.google.com with SMTP id p96so9843558wrb.7 for ; Wed, 25 Oct 2017 04:52:24 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1508767709-15256-4-git-send-email-eric.auger@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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.Valid == 0, for any GITS_BASER register > where the Type field indicates Device. > - GITS_BASER.Valid == 0, for any GITS_BASER 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 > Reported-by: Andre Przywara Reviewed-by: Christoffer Dall > > --- > > 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 >