[PATCH v13 27/48] arm64: RMI: Runtime faulting of memory
Steven Price
steven.price at arm.com
Fri Mar 20 09:44:51 PDT 2026
On 19/03/2026 18:41, Wei-Lin Chang wrote:
> On Wed, Mar 18, 2026 at 03:53:51PM +0000, Steven Price wrote:
>> At runtime if the realm guest accesses memory which hasn't yet been
>> mapped then KVM needs to either populate the region or fault the guest.
>>
>> For memory in the lower (protected) region of IPA a fresh page is
>> provided to the RMM which will zero the contents. For memory in the
>> upper (shared) region of IPA, the memory from the memslot is mapped
>> into the realm VM non secure.
>>
>> Signed-off-by: Steven Price <steven.price at arm.com>
>> ---
>> Changes since v12:
>> * Switch to RMM v2.0 range based APIs.
>> Changes since v11:
>> * Adapt to upstream changes.
>> Changes since v10:
>> * RME->RMI renaming.
>> * Adapt to upstream gmem changes.
>> Changes since v9:
>> * Fix call to kvm_stage2_unmap_range() in kvm_free_stage2_pgd() to set
>> may_block to avoid stall warnings.
>> * Minor coding style fixes.
>> Changes since v8:
>> * Propagate the may_block flag.
>> * Minor comments and coding style changes.
>> Changes since v7:
>> * Remove redundant WARN_ONs for realm_create_rtt_levels() - it will
>> internally WARN when necessary.
>> Changes since v6:
>> * Handle PAGE_SIZE being larger than RMM granule size.
>> * Some minor renaming following review comments.
>> Changes since v5:
>> * Reduce use of struct page in preparation for supporting the RMM
>> having a different page size to the host.
>> * Handle a race when delegating a page where another CPU has faulted on
>> a the same page (and already delegated the physical page) but not yet
>> mapped it. In this case simply return to the guest to either use the
>> mapping from the other CPU (or refault if the race is lost).
>> * The changes to populate_par_region() are moved into the previous
>> patch where they belong.
>> Changes since v4:
>> * Code cleanup following review feedback.
>> * Drop the PTE_SHARED bit when creating unprotected page table entries.
>> This is now set by the RMM and the host has no control of it and the
>> spec requires the bit to be set to zero.
>> Changes since v2:
>> * Avoid leaking memory if failing to map it in the realm.
>> * Correctly mask RTT based on LPA2 flag (see rtt_get_phys()).
>> * Adapt to changes in previous patches.
>> ---
>> arch/arm64/include/asm/kvm_emulate.h | 8 ++
>> arch/arm64/include/asm/kvm_rmi.h | 12 ++
>> arch/arm64/kvm/mmu.c | 139 ++++++++++++++++--
>> arch/arm64/kvm/rmi.c | 206 +++++++++++++++++++++++++++
>> 4 files changed, 351 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
>> index d194d91fbc2a..0734c4a65174 100644
>> --- a/arch/arm64/include/asm/kvm_emulate.h
>> +++ b/arch/arm64/include/asm/kvm_emulate.h
>> @@ -706,6 +706,14 @@ static inline bool kvm_realm_is_created(struct kvm *kvm)
>> return kvm_is_realm(kvm) && kvm_realm_state(kvm) != REALM_STATE_NONE;
>> }
>>
>> +static inline gpa_t kvm_gpa_from_fault(struct kvm *kvm, phys_addr_t ipa)
>
> I think we should use gpa_t as the type for ipa.
This is just matching the usage in mmu.c, e.g. user_mem_abort() has
fault_ipa as a phys_addr_t.
>> +{
>> + if (!kvm_is_realm(kvm))
>> + return ipa;
>> +
>> + return ipa & ~BIT(kvm->arch.realm.ia_bits - 1);
>> +}
>> +
>> static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu)
>> {
>> return kvm_is_realm(vcpu->kvm);
>> diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
>> index bf663bb240c4..38208be3c602 100644
>> --- a/arch/arm64/include/asm/kvm_rmi.h
>> +++ b/arch/arm64/include/asm/kvm_rmi.h
>> @@ -6,6 +6,7 @@
>> #ifndef __ASM_KVM_RMI_H
>> #define __ASM_KVM_RMI_H
>>
>> +#include <asm/kvm_pgtable.h>
>> #include <asm/rmi_smc.h>
>>
>> /**
>> @@ -105,6 +106,17 @@ void kvm_realm_unmap_range(struct kvm *kvm,
>> unsigned long size,
>> bool unmap_private,
>> bool may_block);
>> +int realm_map_protected(struct kvm *kvm,
>> + unsigned long base_ipa,
>> + kvm_pfn_t pfn,
>> + unsigned long size,
>> + struct kvm_mmu_memory_cache *memcache);
>> +int realm_map_non_secure(struct realm *realm,
>> + unsigned long ipa,
>> + kvm_pfn_t pfn,
>> + unsigned long size,
>> + enum kvm_pgtable_prot prot,
>> + struct kvm_mmu_memory_cache *memcache);
>>
>> static inline bool kvm_realm_is_private_address(struct realm *realm,
>> unsigned long addr)
>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
>> index bad93938acdb..73c18c2861a2 100644
>> --- a/arch/arm64/kvm/mmu.c
>> +++ b/arch/arm64/kvm/mmu.c
>> @@ -334,8 +334,15 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64
>>
>> lockdep_assert_held_write(&kvm->mmu_lock);
>> WARN_ON(size & ~PAGE_MASK);
>> - WARN_ON(stage2_apply_range(mmu, start, end, KVM_PGT_FN(kvm_pgtable_stage2_unmap),
>> - may_block));
>> +
>> + if (kvm_is_realm(kvm)) {
>> + kvm_realm_unmap_range(kvm, start, size, !only_shared,
>> + may_block);
>> + } else {
>> + WARN_ON(stage2_apply_range(mmu, start, end,
>> + KVM_PGT_FN(kvm_pgtable_stage2_unmap),
>> + may_block));
>> + }
>> }
>>
>> void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start,
>> @@ -355,7 +362,10 @@ static void stage2_flush_memslot(struct kvm *kvm,
>> phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
>> phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
>>
>> - kvm_stage2_flush_range(&kvm->arch.mmu, addr, end);
>> + if (kvm_is_realm(kvm))
>> + kvm_realm_unmap_range(kvm, addr, end - addr, false, true);
>> + else
>> + kvm_stage2_flush_range(&kvm->arch.mmu, addr, end);
>> }
>>
>> /**
>> @@ -1081,6 +1091,10 @@ void stage2_unmap_vm(struct kvm *kvm)
>> struct kvm_memory_slot *memslot;
>> int idx, bkt;
>>
>> + /* For realms this is handled by the RMM so nothing to do here */
>> + if (kvm_is_realm(kvm))
>> + return;
>> +
>> idx = srcu_read_lock(&kvm->srcu);
>> mmap_read_lock(current->mm);
>> write_lock(&kvm->mmu_lock);
>> @@ -1106,6 +1120,9 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
>> if (kvm_is_realm(kvm) &&
>> (kvm_realm_state(kvm) != REALM_STATE_DEAD &&
>> kvm_realm_state(kvm) != REALM_STATE_NONE)) {
>> + struct realm *realm = &kvm->arch.realm;
>> +
>> + kvm_stage2_unmap_range(mmu, 0, BIT(realm->ia_bits - 1), true);
>> write_unlock(&kvm->mmu_lock);
>> kvm_realm_destroy_rtts(kvm);
>>
>> @@ -1516,6 +1533,29 @@ static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
>> return vma->vm_flags & VM_MTE_ALLOWED;
>> }
>>
>> +static int realm_map_ipa(struct kvm *kvm, phys_addr_t ipa,
>> + kvm_pfn_t pfn, unsigned long map_size,
>> + enum kvm_pgtable_prot prot,
>> + struct kvm_mmu_memory_cache *memcache)
>> +{
>> + struct realm *realm = &kvm->arch.realm;
>> +
>> + /*
>> + * Write permission is required for now even though it's possible to
>> + * map unprotected pages (granules) as read-only. It's impossible to
>> + * map protected pages (granules) as read-only.
>> + */
>> + if (WARN_ON(!(prot & KVM_PGTABLE_PROT_W)))
>> + return -EFAULT;
>> +
>> + ipa = ALIGN_DOWN(ipa, PAGE_SIZE);
>> + if (!kvm_realm_is_private_address(realm, ipa))
>> + return realm_map_non_secure(realm, ipa, pfn, map_size, prot,
>> + memcache);
>> +
>> + return realm_map_protected(kvm, ipa, pfn, map_size, memcache);
>> +}
>> +
>> static bool kvm_vma_is_cacheable(struct vm_area_struct *vma)
>> {
>> switch (FIELD_GET(PTE_ATTRINDX_MASK, pgprot_val(vma->vm_page_prot))) {
>> @@ -1588,6 +1628,7 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
>> enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
>> struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt;
>> + gpa_t gpa = kvm_gpa_from_fault(vcpu->kvm, fault_ipa);
>> unsigned long mmu_seq;
>> struct page *page;
>> struct kvm *kvm = vcpu->kvm;
>> @@ -1596,6 +1637,29 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> gfn_t gfn;
>> int ret;
>>
>> + if (kvm_is_realm(vcpu->kvm)) {
>> + /* check for memory attribute mismatch */
>> + bool is_priv_gfn = kvm_mem_is_private(kvm, gpa >> PAGE_SHIFT);
>> + /*
>> + * For Realms, the shared address is an alias of the private
>> + * PA with the top bit set. Thus is the fault address matches
>
> Hi,
>
> Thus is -> Thus if.
Ack
>> + * the GPA then it is the private alias.
>> + */
>> + bool is_priv_fault = (gpa == fault_ipa);
>> +
>> + if (is_priv_gfn != is_priv_fault) {
>> + kvm_prepare_memory_fault_exit(vcpu, gpa, PAGE_SIZE,
>> + kvm_is_write_fault(vcpu),
>> + false,
>> + is_priv_fault);
>> + /*
>> + * KVM_EXIT_MEMORY_FAULT requires an return code of
>> + * -EFAULT, see the API documentation
>> + */
>> + return -EFAULT;
>> + }
>> + }
>> +
>> ret = prepare_mmu_memcache(vcpu, true, &memcache);
>> if (ret)
>> return ret;
>> @@ -1603,7 +1667,7 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> if (nested)
>> gfn = kvm_s2_trans_output(nested) >> PAGE_SHIFT;
>> else
>> - gfn = fault_ipa >> PAGE_SHIFT;
>> + gfn = gpa >> PAGE_SHIFT;
>>
>> write_fault = kvm_is_write_fault(vcpu);
>> exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
>> @@ -1616,7 +1680,7 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>>
>> ret = kvm_gmem_get_pfn(kvm, memslot, gfn, &pfn, &page, NULL);
>> if (ret) {
>> - kvm_prepare_memory_fault_exit(vcpu, fault_ipa, PAGE_SIZE,
>> + kvm_prepare_memory_fault_exit(vcpu, gpa, PAGE_SIZE,
>> write_fault, exec_fault, false);
>> return ret;
>> }
>> @@ -1638,15 +1702,25 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> kvm_fault_lock(kvm);
>> if (mmu_invalidate_retry(kvm, mmu_seq)) {
>> ret = -EAGAIN;
>> - goto out_unlock;
>> + goto out_release_page;
>> + }
>> +
>> + if (kvm_is_realm(kvm)) {
>> + ret = realm_map_ipa(kvm, fault_ipa, pfn,
>> + PAGE_SIZE, KVM_PGTABLE_PROT_W, memcache);
>> + /* if successful don't release the page */
>> + if (!ret)
>> + goto out_unlock;
>> + goto out_release_page;
>> }
>>
>> ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, fault_ipa, PAGE_SIZE,
>> __pfn_to_phys(pfn), prot,
>> memcache, flags);
>>
>> -out_unlock:
>> +out_release_page:
>> kvm_release_faultin_page(kvm, page, !!ret, writable);
>> +out_unlock:
>> kvm_fault_unlock(kvm);
>>
>> if (writable && !ret)
>> @@ -1685,6 +1759,14 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> if (fault_is_perm)
>> fault_granule = kvm_vcpu_trap_get_perm_fault_granule(vcpu);
>> write_fault = kvm_is_write_fault(vcpu);
>> +
>> + /*
>> + * Realms cannot map protected pages read-only
>> + * FIXME: It should be possible to map unprotected pages read-only
>> + */
>> + if (vcpu_is_rec(vcpu))
>> + write_fault = true;
>> +
>> exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
>> VM_WARN_ON_ONCE(write_fault && exec_fault);
>>
>> @@ -1779,7 +1861,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> ipa &= ~(vma_pagesize - 1);
>> }
>>
>> - gfn = ipa >> PAGE_SHIFT;
>> + gfn = kvm_gpa_from_fault(kvm, ipa) >> PAGE_SHIFT;
>> mte_allowed = kvm_vma_mte_allowed(vma);
>>
>> vfio_allow_any_uc = vma->vm_flags & VM_ALLOW_ANY_UNCACHED;
>> @@ -1855,6 +1937,15 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> if (exec_fault && s2_force_noncacheable)
>> ret = -ENOEXEC;
>>
>> + /*
>> + * For now we shouldn't be hitting protected addresses because they are
>> + * handled in gmem_abort(). In the future this check may be relaxed to
>> + * support e.g. protected devices.
>> + */
>> + if (!ret && vcpu_is_rec(vcpu) &&
>> + kvm_gpa_from_fault(kvm, fault_ipa) == fault_ipa)
>
> Maybe use !shared_ipa_fault() here?
Ack.
Thanks,
Steve
>
> Thanks,
> Wei-Lin Chang
>
>> + ret = -EINVAL;
>> +
>> if (ret) {
>> kvm_release_page_unused(page);
>> return ret;
>> @@ -1939,6 +2030,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>> */
>> prot &= ~KVM_NV_GUEST_MAP_SZ;
>> ret = KVM_PGT_FN(kvm_pgtable_stage2_relax_perms)(pgt, fault_ipa, prot, flags);
>> + } else if (kvm_is_realm(kvm)) {
>> + ret = realm_map_ipa(kvm, fault_ipa, pfn, vma_pagesize,
>> + prot, memcache);
>> } else {
>> ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, fault_ipa, vma_pagesize,
>> __pfn_to_phys(pfn), prot,
>> @@ -2049,6 +2143,13 @@ int kvm_handle_guest_sea(struct kvm_vcpu *vcpu)
>> return 0;
>> }
>>
>> +static bool shared_ipa_fault(struct kvm *kvm, phys_addr_t fault_ipa)
>> +{
>> + gpa_t gpa = kvm_gpa_from_fault(kvm, fault_ipa);
>> +
>> + return (gpa != fault_ipa);
>> +}
>> +
>> /**
>> * kvm_handle_guest_abort - handles all 2nd stage aborts
>> * @vcpu: the VCPU pointer
>> @@ -2159,8 +2260,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
>> nested = &nested_trans;
>> }
>>
>> - gfn = ipa >> PAGE_SHIFT;
>> + gfn = kvm_gpa_from_fault(vcpu->kvm, ipa) >> PAGE_SHIFT;
>> memslot = gfn_to_memslot(vcpu->kvm, gfn);
>> +
>> hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
>> write_fault = kvm_is_write_fault(vcpu);
>> if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
>> @@ -2203,7 +2305,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
>> * of the page size.
>> */
>> ipa |= FAR_TO_FIPA_OFFSET(kvm_vcpu_get_hfar(vcpu));
>> - ret = io_mem_abort(vcpu, ipa);
>> + ret = io_mem_abort(vcpu, kvm_gpa_from_fault(vcpu->kvm, ipa));
>> goto out_unlock;
>> }
>>
>> @@ -2219,7 +2321,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
>> VM_WARN_ON_ONCE(kvm_vcpu_trap_is_permission_fault(vcpu) &&
>> !write_fault && !kvm_vcpu_trap_is_exec_fault(vcpu));
>>
>> - if (kvm_slot_has_gmem(memslot))
>> + if (kvm_slot_has_gmem(memslot) && !shared_ipa_fault(vcpu->kvm, fault_ipa))
>> ret = gmem_abort(vcpu, fault_ipa, nested, memslot,
>> esr_fsc_is_permission_fault(esr));
>> else
>> @@ -2256,6 +2358,10 @@ bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
>> if (!kvm->arch.mmu.pgt)
>> return false;
>>
>> + /* We don't support aging for Realms */
>> + if (kvm_is_realm(kvm))
>> + return true;
>> +
>> return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
>> range->start << PAGE_SHIFT,
>> size, true);
>> @@ -2272,6 +2378,10 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
>> if (!kvm->arch.mmu.pgt)
>> return false;
>>
>> + /* We don't support aging for Realms */
>> + if (kvm_is_realm(kvm))
>> + return true;
>> +
>> return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
>> range->start << PAGE_SHIFT,
>> size, false);
>> @@ -2438,10 +2548,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
>> return -EFAULT;
>>
>> /*
>> - * Only support guest_memfd backed memslots with mappable memory, since
>> - * there aren't any CoCo VMs that support only private memory on arm64.
>> + * Only support guest_memfd backed memslots with mappable memory,
>> + * unless the guest is a CCA realm guest.
>> */
>> - if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new))
>> + if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new) &&
>> + !kvm_is_realm(kvm))
>> return -EINVAL;
>>
>> hva = new->userspace_addr;
>> diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
>> index d5fee203824b..30292814b1ec 100644
>> --- a/arch/arm64/kvm/rmi.c
>> +++ b/arch/arm64/kvm/rmi.c
>> @@ -837,6 +837,212 @@ static int realm_create_protected_data_page(struct kvm *kvm,
>> return ret;
>> }
>>
>> +static int fold_rtt(struct realm *realm, unsigned long addr, int level)
>> +{
>> + phys_addr_t rtt_addr;
>> + int ret;
>> +
>> + ret = realm_rtt_fold(realm, addr, level, &rtt_addr);
>> + if (ret)
>> + return ret;
>> +
>> + free_rtt(rtt_addr);
>> +
>> + return 0;
>> +}
>> +
>> +static unsigned long addr_range_desc(unsigned long phys, unsigned long size)
>> +{
>> + unsigned long out = 0;
>> +
>> + switch (size) {
>> + case P4D_SIZE:
>> + out = 0 | (1 << 2);
>> + break;
>> + case PUD_SIZE:
>> + out = 1 | (1 << 2);
>> + break;
>> + case PMD_SIZE:
>> + out = 2 | (1 << 2);
>> + break;
>> + case PAGE_SIZE:
>> + out = 3 | (1 << 2);
>> + break;
>> + default:
>> + /*
>> + * Only support mapping at the page level granulatity when
>> + * it's an unusual length. This should get us back onto a larger
>> + * block size for the subsequent mappings.
>> + */
>> + out = 3 | ((MIN(size >> PAGE_SHIFT, PTRS_PER_PTE - 1)) << 2);
>> + break;
>> + }
>> +
>> + WARN_ON(phys & ~PAGE_MASK);
>> +
>> + out |= phys & PAGE_MASK;
>> +
>> + return out;
>> +}
>> +
>> +int realm_map_protected(struct kvm *kvm,
>> + unsigned long ipa,
>> + kvm_pfn_t pfn,
>> + unsigned long map_size,
>> + struct kvm_mmu_memory_cache *memcache)
>> +{
>> + struct realm *realm = &kvm->arch.realm;
>> + phys_addr_t phys = __pfn_to_phys(pfn);
>> + phys_addr_t rd = virt_to_phys(realm->rd);
>> + unsigned long base_ipa = ipa;
>> + unsigned long ipa_top = ipa + map_size;
>> + int map_level = IS_ALIGNED(map_size, RMM_L2_BLOCK_SIZE) ?
>> + RMM_RTT_BLOCK_LEVEL : RMM_RTT_MAX_LEVEL;
>> + int ret = 0;
>> +
>> + if (WARN_ON(!IS_ALIGNED(map_size, PAGE_SIZE) ||
>> + !IS_ALIGNED(ipa, map_size)))
>> + return -EINVAL;
>> +
>> + if (map_level < RMM_RTT_MAX_LEVEL) {
>> + /*
>> + * A temporary RTT is needed during the map, precreate it,
>> + * however if there is an error (e.g. missing parent tables)
>> + * this will be handled below.
>> + */
>> + realm_create_rtt_levels(realm, ipa, map_level,
>> + RMM_RTT_MAX_LEVEL, memcache);
>> + }
>> +
>> + if (delegate_range(phys, map_size)) {
>> + /*
>> + * It's likely we raced with another VCPU on the same
>> + * fault. Assume the other VCPU has handled the fault
>> + * and return to the guest.
>> + */
>> + return 0;
>> + }
>> +
>> + while (ipa < ipa_top) {
>> + unsigned long flags = RMI_ADDR_TYPE_SINGLE;
>> + unsigned long range_desc = addr_range_desc(phys, ipa_top - ipa);
>> + unsigned long out_top;
>> +
>> + ret = rmi_rtt_data_map(rd, ipa, ipa_top, flags, range_desc,
>> + &out_top);
>> +
>> + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
>> + /* Create missing RTTs and retry */
>> + int level = RMI_RETURN_INDEX(ret);
>> +
>> + WARN_ON(level == RMM_RTT_MAX_LEVEL);
>> + ret = realm_create_rtt_levels(realm, ipa, level,
>> + RMM_RTT_MAX_LEVEL,
>> + memcache);
>> + if (ret)
>> + goto err_undelegate;
>> +
>> + ret = rmi_rtt_data_map(rd, ipa, ipa_top, flags,
>> + range_desc, &out_top);
>> + }
>> +
>> + if (WARN_ON(ret))
>> + goto err_undelegate;
>> +
>> + phys += out_top - ipa;
>> + ipa = out_top;
>> + }
>> +
>> + if (map_size == RMM_L2_BLOCK_SIZE) {
>> + ret = fold_rtt(realm, base_ipa, map_level + 1);
>> + if (WARN_ON(ret))
>> + goto err;
>> + }
>> +
>> + return 0;
>> +
>> +err_undelegate:
>> + if (WARN_ON(undelegate_range(phys, map_size))) {
>> + /* Page can't be returned to NS world so is lost */
>> + get_page(phys_to_page(phys));
>> + }
>> +err:
>> + realm_unmap_private_range(kvm, base_ipa, ipa, true);
>> + return -ENXIO;
>> +}
>> +
>> +int realm_map_non_secure(struct realm *realm,
>> + unsigned long ipa,
>> + kvm_pfn_t pfn,
>> + unsigned long size,
>> + enum kvm_pgtable_prot prot,
>> + struct kvm_mmu_memory_cache *memcache)
>> +{
>> + unsigned long attr;
>> + phys_addr_t rd = virt_to_phys(realm->rd);
>> + phys_addr_t phys = __pfn_to_phys(pfn);
>> + unsigned long offset;
>> + /* TODO: Support block mappings */
>> + int map_level = RMM_RTT_MAX_LEVEL;
>> + int map_size = rmi_rtt_level_mapsize(map_level);
>> + int ret = 0;
>> +
>> + if (WARN_ON(!IS_ALIGNED(size, PAGE_SIZE) ||
>> + !IS_ALIGNED(ipa, size)))
>> + return -EINVAL;
>> +
>> + switch (prot & (KVM_PGTABLE_PROT_DEVICE | KVM_PGTABLE_PROT_NORMAL_NC)) {
>> + case KVM_PGTABLE_PROT_DEVICE | KVM_PGTABLE_PROT_NORMAL_NC:
>> + return -EINVAL;
>> + case KVM_PGTABLE_PROT_DEVICE:
>> + attr = PTE_S2_MEMATTR(MT_S2_FWB_DEVICE_nGnRE);
>> + break;
>> + case KVM_PGTABLE_PROT_NORMAL_NC:
>> + attr = PTE_S2_MEMATTR(MT_S2_FWB_NORMAL_NC);
>> + break;
>> + default:
>> + attr = PTE_S2_MEMATTR(MT_S2_FWB_NORMAL);
>> + }
>> +
>> + for (offset = 0; offset < size; offset += map_size) {
>> + /*
>> + * realm_map_ipa() enforces that the memory is writable,
>> + * so for now we permit both read and write.
>> + */
>> + unsigned long desc = kvm_phys_to_pte(phys) | attr |
>> + KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R |
>> + KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W;
>> + ret = rmi_rtt_map_unprotected(rd, ipa, map_level, desc);
>> +
>> + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
>> + /* Create missing RTTs and retry */
>> + int level = RMI_RETURN_INDEX(ret);
>> +
>> + ret = realm_create_rtt_levels(realm, ipa, level,
>> + map_level, memcache);
>> + if (ret)
>> + return -ENXIO;
>> +
>> + ret = rmi_rtt_map_unprotected(rd, ipa, map_level, desc);
>> + }
>> + /*
>> + * RMI_ERROR_RTT can be reported for two reasons: either the
>> + * RTT tables are not there, or there is an RTTE already
>> + * present for the address. The above call to create RTTs
>> + * handles the first case, and in the second case this
>> + * indicates that another thread has already populated the RTTE
>> + * for us, so we can ignore the error and continue.
>> + */
>> + if (ret && RMI_RETURN_STATUS(ret) != RMI_ERROR_RTT)
>> + return -ENXIO;
>> +
>> + ipa += map_size;
>> + phys += map_size;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
>> struct page *src_page, void *opaque)
>> {
>> --
>> 2.43.0
>>
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