From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH v4 06/11] KVM: arm/arm64: vgic-its: Check GITS_CBASER validity before processing commands Date: Wed, 18 Oct 2017 00:10:16 +0200 Message-ID: <20171017221016.GF8326@lvm> References: <1508224209-15366-1-git-send-email-eric.auger@redhat.com> <1508224209-15366-7-git-send-email-eric.auger@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, marc.zyngier@arm.com, andre.przywara@arm.com, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, wu.wubin@huawei.com, eric.auger.pro@gmail.com To: Eric Auger Return-path: Content-Disposition: inline In-Reply-To: <1508224209-15366-7-git-send-email-eric.auger@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org On Tue, Oct 17, 2017 at 09:10:04AM +0200, Eric Auger wrote: > At the moment vgic_its_process_commands() does not > check the CBASER is valid before processing any command. > Let's fix that. > > Also rename cbaser local variable into cbaser_pa to avoid > any confusion with the full register. > > Signed-off-by: Eric Auger > --- > virt/kvm/arm/vgic/vgic-its.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index 3b539d4..e18f1e4 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -1301,17 +1301,20 @@ static void vgic_mmio_write_its_cbaser(struct kvm *kvm, struct vgic_its *its, > /* Must be called with the cmd_lock held. */ > static void vgic_its_process_commands(struct kvm *kvm, struct vgic_its *its) > { > - gpa_t cbaser; > + gpa_t cbaser_pa; > u64 cmd_buf[4]; > > - /* Commands are only processed when the ITS is enabled. */ > - if (!its->enabled) > + /* > + * Commands are only processed when the ITS is enabled and > + * CBASER is valid > + */ > + if (!its->enabled || (!(its->cbaser & GITS_CBASER_VALID))) Is it valid to clear the CBASER valid bit after having enabled the ITS? If not, I think you should check changes to CBASER and then this shouldn't be necessary. > return; > > - cbaser = CBASER_ADDRESS(its->cbaser); > + cbaser_pa = CBASER_ADDRESS(its->cbaser); > > while (its->cwriter != its->creadr) { > - int ret = kvm_read_guest(kvm, cbaser + its->creadr, > + int ret = kvm_read_guest(kvm, cbaser_pa + its->creadr, > cmd_buf, ITS_CMD_SIZE); > /* > * If kvm_read_guest() fails, this could be due to the guest > -- > 2.5.5 > Otherwise, this looks fine. Thanks, -Christoffer