[PATCH v1 6/6] KVM: arm64: Use kvm_s2_fault_vma_info in pkvm_mem_abort()
COOLING6d
From: Vincent Donnefort <hidden>
Date: 2026-09-22 13:08:34
Also in:
kvmarm, stable
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
To paraphrase Marc in commit 08f97454b7fa ("KVM: arm64: Fix protected
mode handling of pages larger than 4kB"), pkvm_pgtable_stage2_map()
assumes the address passed as a parameter is aligned to the size of the
intended mapping, while HPFAR_EL2 gives the IPA minus the bottom 12
bits, regardless of the system page size configuration.
To fix this alignment, bring support for kvm_s2_fault_vma_info in
pkvm_mem_abort() and use its members where possible. They do contain the
page-alignment we need to fix the fault on system with pages larger than
4K.
Also, add a check at the start of pkvm_pgtable_stage2_map(), it does not
support !PAGE_ALIGNED arguments.
Fixes: ea03466e806f ("KVM: arm64: Handle aborts from protected VMs")
Cc: stable@vger.kernel.org
Signed-off-by: Vincent Donnefort <redacted>
---
arch/arm64/kvm/mmu.c | 24 +++++++++++++++---------
arch/arm64/kvm/pkvm.c | 3 +++
2 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index ee0fcca838c1..167b769107ee 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c@@ -1374,9 +1374,11 @@ static bool fault_supports_stage2_huge_mapping(const struct kvm_s2_fault_desc *s if (map_size == PAGE_SIZE) return true; - /* pKVM only supports PMD_SIZE huge-mappings */ - if (is_protected_kvm_enabled() && map_size != PMD_SIZE) - return false; + /* pKVM only supports PMD_SIZE huge-mappings for non-protected VMs */ + if (is_protected_kvm_enabled()) { + if (vcpu_is_protected(s2fd->vcpu) || map_size != PMD_SIZE) + return false; + } size = memslot->npages * PAGE_SIZE;
@@ -2167,12 +2169,12 @@ int kvm_handle_guest_sea(struct kvm_vcpu *vcpu) static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd) { unsigned int flags = FOLL_HWPOISON | FOLL_LONGTERM | FOLL_WRITE; + struct kvm_s2_fault_vma_info s2vi = {}; struct kvm_vcpu *vcpu = s2fd->vcpu; struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt; struct mm_struct *mm = current->mm; struct kvm *kvm = vcpu->kvm; void *hyp_memcache; - struct page *page; int ret; hyp_memcache = get_mmu_memcache(vcpu);
@@ -2180,12 +2182,16 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd) if (ret) return -ENOMEM; + ret = kvm_s2_fault_get_vma_info(s2fd, &s2vi); + if (ret) + return ret; + ret = account_locked_vm(mm, 1, true); if (ret) return ret; mmap_read_lock(mm); - ret = pin_user_pages(s2fd->hva, 1, flags, &page); + ret = pin_user_pages(s2fd->hva, 1, flags, &s2vi.page); mmap_read_unlock(mm); if (ret == -EHWPOISON) {
@@ -2195,7 +2201,7 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd) } else if (ret != 1) { ret = -EFAULT; goto dec_account; - } else if (!folio_test_swapbacked(page_folio(page))) { + } else if (!folio_test_swapbacked(page_folio(s2vi.page))) { /* * We really can't deal with page-cache pages returned by GUP * because (a) we may trigger writeback of a page for which we
@@ -2215,8 +2221,8 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd) } write_lock(&kvm->mmu_lock); - ret = pkvm_pgtable_stage2_map(pgt, s2fd->fault_ipa, PAGE_SIZE, - page_to_phys(page), KVM_PGTABLE_PROT_RWX, + ret = pkvm_pgtable_stage2_map(pgt, gfn_to_gpa(s2vi.gfn), PAGE_SIZE, + page_to_phys(s2vi.page), KVM_PGTABLE_PROT_RWX, hyp_memcache, 0); write_unlock(&kvm->mmu_lock); if (ret) {
@@ -2227,7 +2233,7 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd) return 0; unpin: - unpin_user_pages(&page, 1); + unpin_user_page(s2vi.page); dec_account: account_locked_vm(mm, 1, false); return ret;
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 8e4c6e4bec12..c298a5b9b12a 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c@@ -414,6 +414,9 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 end = addr + size; int ret; + if (WARN_ON_ONCE(!PAGE_ALIGNED(addr | size))) + return -EINVAL; + lockdep_assert_held_write(&kvm->mmu_lock); mapping = pkvm_mapping_iter_first(&pgt->pkvm_mappings, addr, end - 1);
--
2.55.0.1082.g2b9226bbc0-goog