| Message ID | 20210319100146.1149909-34-qperret@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Stage-2 for the host | expand |
On Fri, Mar 19, 2021 at 10:01:41AM +0000, Quentin Perret wrote: > Introduce a new stage 2 configuration flag to specify that all mappings > in a given page-table will be identity-mapped, as will be the case for > the host. This allows to introduce sanity checks in the map path and to > avoid programming errors. > > Suggested-by: Will Deacon <will@kernel.org> > Signed-off-by: Quentin Perret <qperret@google.com> > --- > arch/arm64/include/asm/kvm_pgtable.h | 2 ++ > arch/arm64/kvm/hyp/pgtable.c | 3 +++ > 2 files changed, 5 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h > index 55452f4831d2..c3674c47d48c 100644 > --- a/arch/arm64/include/asm/kvm_pgtable.h > +++ b/arch/arm64/include/asm/kvm_pgtable.h > @@ -60,9 +60,11 @@ struct kvm_pgtable_mm_ops { > * enum kvm_pgtable_stage2_flags - Stage-2 page-table flags. > * @KVM_PGTABLE_S2_NOFWB: Don't enforce Normal-WB even if the CPUs have > * ARM64_HAS_STAGE2_FWB. > + * @KVM_PGTABLE_S2_IDMAP: Only use identity mappings. > */ > enum kvm_pgtable_stage2_flags { > KVM_PGTABLE_S2_NOFWB = BIT(0), > + KVM_PGTABLE_S2_IDMAP = BIT(1), > }; > > /** > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index b22b4860630c..c37c1dc4feaf 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -760,6 +760,9 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, > .arg = &map_data, > }; > > + if (WARN_ON((pgt->flags & KVM_PGTABLE_S2_IDMAP) && (addr != phys))) > + return -EINVAL; Acked-by: Will Deacon <will@kernel.org> Will
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 55452f4831d2..c3674c47d48c 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -60,9 +60,11 @@ struct kvm_pgtable_mm_ops { * enum kvm_pgtable_stage2_flags - Stage-2 page-table flags. * @KVM_PGTABLE_S2_NOFWB: Don't enforce Normal-WB even if the CPUs have * ARM64_HAS_STAGE2_FWB. + * @KVM_PGTABLE_S2_IDMAP: Only use identity mappings. */ enum kvm_pgtable_stage2_flags { KVM_PGTABLE_S2_NOFWB = BIT(0), + KVM_PGTABLE_S2_IDMAP = BIT(1), }; /** diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index b22b4860630c..c37c1dc4feaf 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -760,6 +760,9 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, .arg = &map_data, }; + if (WARN_ON((pgt->flags & KVM_PGTABLE_S2_IDMAP) && (addr != phys))) + return -EINVAL; + ret = stage2_set_prot_attr(pgt, prot, &map_data.attr); if (ret) return ret;
Introduce a new stage 2 configuration flag to specify that all mappings in a given page-table will be identity-mapped, as will be the case for the host. This allows to introduce sanity checks in the map path and to avoid programming errors. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> --- arch/arm64/include/asm/kvm_pgtable.h | 2 ++ arch/arm64/kvm/hyp/pgtable.c | 3 +++ 2 files changed, 5 insertions(+)