| Message ID | 20231108111806.92604-16-nsaenz@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: hyperv: Introduce VSM support | expand |
On Wed, 2023-11-08 at 11:17 +0000, Nicolas Saenz Julienne wrote: > The upcoming per-VTL memory protections support needs to fault in > non-executable memory. Introduce a new attribute in struct > kvm_page_fault, map_executable, to control whether the gfn range should > be mapped as executable. > > No functional change intended. > > Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com> > --- > arch/x86/kvm/mmu/mmu.c | 6 +++++- > arch/x86/kvm/mmu/mmu_internal.h | 2 ++ > arch/x86/kvm/mmu/tdp_mmu.c | 8 ++++++-- > 3 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 2afef86863fb..4e02d506cc25 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -3245,6 +3245,7 @@ static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) > struct kvm_mmu_page *sp; > int ret; > gfn_t base_gfn = fault->gfn; > + unsigned access = ACC_ALL; > > kvm_mmu_hugepage_adjust(vcpu, fault); > > @@ -3274,7 +3275,10 @@ static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) > if (WARN_ON_ONCE(it.level != fault->goal_level)) > return -EFAULT; > > - ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, > + if (!fault->map_executable) > + access &= ~ACC_EXEC_MASK; > + > + ret = mmu_set_spte(vcpu, fault->slot, it.sptep, access, > base_gfn, fault->pfn, fault); > if (ret == RET_PF_SPURIOUS) > return ret; > diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h > index b66a7d47e0e4..bd62c4d5d5f1 100644 > --- a/arch/x86/kvm/mmu/mmu_internal.h > +++ b/arch/x86/kvm/mmu/mmu_internal.h > @@ -239,6 +239,7 @@ struct kvm_page_fault { > kvm_pfn_t pfn; > hva_t hva; > bool map_writable; > + bool map_executable; > > /* > * Indicates the guest is trying to write a gfn that contains one or > @@ -298,6 +299,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, > .req_level = PG_LEVEL_4K, > .goal_level = PG_LEVEL_4K, > .is_private = kvm_mem_is_private(vcpu->kvm, cr2_or_gpa >> PAGE_SHIFT), > + .map_executable = true, > }; > int r; > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index 6cd4dd631a2f..46f3e72ab770 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -957,14 +957,18 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, > u64 new_spte; > int ret = RET_PF_FIXED; > bool wrprot = false; > + unsigned access = ACC_ALL; > > if (WARN_ON_ONCE(sp->role.level != fault->goal_level)) > return RET_PF_RETRY; > > + if (!fault->map_executable) > + access &= ~ACC_EXEC_MASK; > + > if (unlikely(!fault->slot)) > - new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL); > + new_spte = make_mmio_spte(vcpu, iter->gfn, access); > else > - wrprot = make_spte(vcpu, sp, fault->slot, ACC_ALL, iter->gfn, > + wrprot = make_spte(vcpu, sp, fault->slot, access, iter->gfn, > fault->pfn, iter->old_spte, fault->prefetch, true, > fault->map_writable, &new_spte); Overall this patch makes sense but I don't know the mmu well enough to be sure that there are no corner cases which are not handeled here. > Best regards, Maxim Levitsky
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 2afef86863fb..4e02d506cc25 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3245,6 +3245,7 @@ static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) struct kvm_mmu_page *sp; int ret; gfn_t base_gfn = fault->gfn; + unsigned access = ACC_ALL; kvm_mmu_hugepage_adjust(vcpu, fault); @@ -3274,7 +3275,10 @@ static int direct_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) if (WARN_ON_ONCE(it.level != fault->goal_level)) return -EFAULT; - ret = mmu_set_spte(vcpu, fault->slot, it.sptep, ACC_ALL, + if (!fault->map_executable) + access &= ~ACC_EXEC_MASK; + + ret = mmu_set_spte(vcpu, fault->slot, it.sptep, access, base_gfn, fault->pfn, fault); if (ret == RET_PF_SPURIOUS) return ret; diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index b66a7d47e0e4..bd62c4d5d5f1 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -239,6 +239,7 @@ struct kvm_page_fault { kvm_pfn_t pfn; hva_t hva; bool map_writable; + bool map_executable; /* * Indicates the guest is trying to write a gfn that contains one or @@ -298,6 +299,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, .req_level = PG_LEVEL_4K, .goal_level = PG_LEVEL_4K, .is_private = kvm_mem_is_private(vcpu->kvm, cr2_or_gpa >> PAGE_SHIFT), + .map_executable = true, }; int r; diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 6cd4dd631a2f..46f3e72ab770 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -957,14 +957,18 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, u64 new_spte; int ret = RET_PF_FIXED; bool wrprot = false; + unsigned access = ACC_ALL; if (WARN_ON_ONCE(sp->role.level != fault->goal_level)) return RET_PF_RETRY; + if (!fault->map_executable) + access &= ~ACC_EXEC_MASK; + if (unlikely(!fault->slot)) - new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL); + new_spte = make_mmio_spte(vcpu, iter->gfn, access); else - wrprot = make_spte(vcpu, sp, fault->slot, ACC_ALL, iter->gfn, + wrprot = make_spte(vcpu, sp, fault->slot, access, iter->gfn, fault->pfn, iter->old_spte, fault->prefetch, true, fault->map_writable, &new_spte);
The upcoming per-VTL memory protections support needs to fault in non-executable memory. Introduce a new attribute in struct kvm_page_fault, map_executable, to control whether the gfn range should be mapped as executable. No functional change intended. Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com> --- arch/x86/kvm/mmu/mmu.c | 6 +++++- arch/x86/kvm/mmu/mmu_internal.h | 2 ++ arch/x86/kvm/mmu/tdp_mmu.c | 8 ++++++-- 3 files changed, 13 insertions(+), 3 deletions(-)