On Wed, Sep 8, 2021 at 5:50 PM Ricardo Koller <ricarkol@xxxxxxxxxx> wrote: > > On Wed, Sep 08, 2021 at 09:32:05PM +0000, Oliver Upton wrote: > > Hi Ricardo, > > > > On Wed, Sep 08, 2021 at 02:03:19PM -0700, Ricardo Koller wrote: > > > Extend vgic_v3_check_base() to verify that the redistributor regions > > > don't go above the VM-specified IPA size (phys_size). This can happen > > > when using the legacy KVM_VGIC_V3_ADDR_TYPE_REDIST attribute with: > > > > > > base + size > phys_size AND base < phys_size > > > > > > vgic_v3_check_base() is used to check the redist regions bases when > > > setting them (with the vcpus added so far) and when attempting the first > > > vcpu-run. > > > > > > Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx> > > > --- > > > arch/arm64/kvm/vgic/vgic-v3.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c > > > index 66004f61cd83..5afd9f6f68f6 100644 > > > --- a/arch/arm64/kvm/vgic/vgic-v3.c > > > +++ b/arch/arm64/kvm/vgic/vgic-v3.c > > > @@ -512,6 +512,10 @@ bool vgic_v3_check_base(struct kvm *kvm) > > > if (rdreg->base + vgic_v3_rd_region_size(kvm, rdreg) < > > > rdreg->base) > > > return false; > > > > Can we drop this check in favor of explicitly comparing rdreg->base with > > kvm_phys_size()? I believe that would be more readable. > > > > You mean the integer overflow check above? in that case, I would prefer > to leave it, if you don't mind. It seems that this type of check is used > in some other places in KVM (like kvm_assign_ioeventfd and > vgic_v3_alloc_redist_region). I would expect rdreg->base to exceed kvm_phys_size() before wrapping, but we do derive rdreg->count from what userspace gives us. In that case, your addition in combination with this makes sense, so no real objections here. > > > + > > > + if (rdreg->base + vgic_v3_rd_region_size(kvm, rdreg) > > > > + kvm_phys_size(kvm)) > > > + return false; > > > } > > > > > > if (IS_VGIC_ADDR_UNDEF(d->vgic_dist_base)) > > > -- > > > 2.33.0.153.gba50c8fa24-goog > > > > > > > -- > > Thanks, > > Oliver Reviewed-by: Oliver Upton <oupton@xxxxxxxxxx>
