Messages in this thread | | | Subject | Re: [PATCH] KVM: arm/arm64: vgic-its: Fix restoration of unmapped collections | From | Zenghui Yu <> | Date | Fri, 13 Dec 2019 18:53:53 +0800 |
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Hi Eric,
On 2019/12/13 17:42, Eric Auger wrote: > Saving/restoring an unmapped collection is a valid scenario. For > example this happens if a MAPTI command was sent, featuring an > unmapped collection. At the moment the CTE fails to be restored. > Only compare against the number of online vcpus if the rdist > base is set.
Have you actually seen a problem and this patch fixed it? To be honest, I'm surprised to find that we can map a LPI to an unmapped collection ;) (and prevent it to be delivered to vcpu with an INT_UNMAPPED_INTERRUPT error, until someone had actually mapped the collection). After a quick glance of spec (MAPTI), just as you said, this is valid.
If Marc has no objection to this fix, please add
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thanks, Zenghui
> > Cc: stable@vger.kernel.org # v4.11+ > Fixes: ea1ad53e1e31a ("KVM: arm64: vgic-its: Collection table save/restore") > Signed-off-by: Eric Auger <eric.auger@redhat.com> > --- > virt/kvm/arm/vgic/vgic-its.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > index 98c7360d9fb7..17920d1b350a 100644 > --- a/virt/kvm/arm/vgic/vgic-its.c > +++ b/virt/kvm/arm/vgic/vgic-its.c > @@ -2475,7 +2475,8 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) > target_addr = (u32)(val >> KVM_ITS_CTE_RDBASE_SHIFT); > coll_id = val & KVM_ITS_CTE_ICID_MASK; > > - if (target_addr >= atomic_read(&kvm->online_vcpus)) > + if (target_addr != COLLECTION_NOT_MAPPED && > + target_addr >= atomic_read(&kvm->online_vcpus)) > return -EINVAL; > > collection = find_collection(its, coll_id); >
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