On Fri, Oct 06, 2017 at 05:29:02PM +0200, Auger Eric wrote: > Hi, > > On 06/10/2017 16:37, Andre Przywara wrote: > > 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. > Oh OK, you're. I missed that. I would have sworn I've seen that failure > but I must have misinterpreted it. >
What is CWRITER is written to a brand new ITS before the CBASER is written? I don't see us initializing the cbaser field anywhere? Thanks, -Christoffer > > > > What am I missing here? > > > > Cheers, > > Andre. > > > >> Signed-off-by: Eric Auger <eric.au...@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; > >> } > >>