[PATCH v1] KVM: arm64: Fix protected VMs fault on system with pages larger than 4K

[PATCH v1] KVM: arm64: Fix protected VMs fault on system with pages larger than 4K

[Vincent Donnefort]

Just like commit 08f97454b7fa ("KVM: arm64: Fix protected mode handling
of pages larger than 4kB") fixed the boot of non-protected VMs on system
larger than 4K pages, align the fault IPA down to the page-size for
protected VMs.

To paraphrase Marc, 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.

Add a check at the start of pkvm_pgtable_stage2_map() as we do not
support !PAGE_ALIGNED arguments.

Fixes: ea03466e806f ("KVM: arm64: Handle aborts from protected VMs")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
---
 arch/arm64/kvm/mmu.c  | 2 +-
 arch/arm64/kvm/pkvm.c | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 9ba86450fe4a..e8d98957531a 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1756,7 +1756,7 @@ 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,
+	ret = pkvm_pgtable_stage2_map(pgt, ALIGN_DOWN(s2fd->fault_ipa, PAGE_SIZE), PAGE_SIZE,
 				      page_to_phys(page), KVM_PGTABLE_PROT_RWX,
 				      hyp_memcache, 0);
 	write_unlock(&kvm->mmu_lock);
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 8e4c6e4bec12..1ca27d01a3ec 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 (!PAGE_ALIGNED(addr | size | phys))
+		return -EINVAL;
+
 	lockdep_assert_held_write(&kvm->mmu_lock);
 	mapping = pkvm_mapping_iter_first(&pgt->pkvm_mappings, addr, end - 1);
 

base-commit: df2908090cda368b01ff43709f51890076c56157
-- 
2.55.0.1007.g17ff1f9808-goog