Physical device assignment is not yet supported by the RMM, so it doesn't make much sense to allow device mappings within the realm. Prevent them when the guest is a realm. Signed-off-by: Steven Price <steven.price@xxxxxxx> --- Changes from v6: * Fix the check in user_mem_abort() to prevent all pages that are not guest_memfd() from being mapped into the protected half of the IPA. Changes from v5: * Also prevent accesses in user_mem_abort() --- arch/arm64/kvm/mmu.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 8c656a0ef4e9..a849ff66e584 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1173,6 +1173,10 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, if (is_protected_kvm_enabled()) return -EPERM; + /* We don't support mapping special pages into a Realm */ + if (kvm_is_realm(kvm)) + return -EPERM; + size += offset_in_page(guest_ipa); guest_ipa &= PAGE_MASK; @@ -1763,6 +1767,15 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault && device) return -ENOEXEC; + /* + * For now we shouldn't be hitting protected addresses because they are + * handled in private_memslot_fault(). In the future this check may be + * relaxed to support e.g. protected devices. + */ + if (vcpu_is_rec(vcpu) && + kvm_gpa_from_fault(kvm, fault_ipa) == fault_ipa) + return -EINVAL; + /* * Potentially reduce shadow S2 permissions to match the guest's own * S2. For exec faults, we'd only reach this point if the guest -- 2.43.0
