Messages in this thread | | | Subject | Re: [PATCH v2 02/10] KVM: arm/arm64: vgic-its: Always allow clearing GITS_CREADR/CWRITER | From | Andre Przywara <> | Date | Fri, 6 Oct 2017 15:37:37 +0100 |
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Hi,
On 27/09/17 14:28, Eric Auger wrote: > If the GITS_CBASER Size field is 0, which can correspond to a > reset value, the userspace fails to set the GITS_CREADR/CWRITER > offsets to 0. This failure is not justified. > > Let's allow this setting which can also correspond to a reset value.
But the GITS_CBASER size field has a +1 encoding, so can never be 0, if I understand the manual (and ITS_CMD_BUFFER_SIZE) correctly.
What am I missing here?
Cheers, Andre.
> Signed-off-by: Eric Auger <eric.auger@redhat.com> > > --- > > need to CC stable > --- > virt/kvm/arm/vgic/vgic-its.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index fbbc97b..76bed2d 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -1329,7 +1329,7 @@ static void vgic_mmio_write_its_cwriter(struct kvm *kvm, struct vgic_its *its, > > reg = update_64bit_reg(its->cwriter, addr & 7, len, val); > reg = ITS_CMD_OFFSET(reg); > - if (reg >= ITS_CMD_BUFFER_SIZE(its->cbaser)) { > + if (reg && reg >= ITS_CMD_BUFFER_SIZE(its->cbaser)) { > mutex_unlock(&its->cmd_lock); > return; > } > @@ -1370,7 +1370,7 @@ static int vgic_mmio_uaccess_write_its_creadr(struct kvm *kvm, > } > > cmd_offset = ITS_CMD_OFFSET(val); > - if (cmd_offset >= ITS_CMD_BUFFER_SIZE(its->cbaser)) { > + if (cmd_offset && cmd_offset >= ITS_CMD_BUFFER_SIZE(its->cbaser)) { > ret = -EINVAL; > goto out; > } >
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