[PATCH v13 27/48] arm64: RMI: Runtime faulting of memory

Steven Price
2026-03-18T15:56:04Z

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@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)
+{
+ 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
+ * 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)
+ 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