KVM: arm64: Fix propagation of TLBI level in kvm_pgtable_stage2_relax_perms()

Assigning the invalidation level (an s8 value) with TLBI_TTL_UNKNOWN
(a 32bit signed value) is not ideal, to say the least. Instead of
this, only pass TLBI_TTL_UNKNOWN to __kvm_tlb_flush_vmid_ipa_nsh()
when we know for sure that we don't have a provided level.

Fixes: 100baf0184896 ("KVM: arm64: Ensure level is always initialized when relaxing perms")
Reported-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://lore.kernel.org/r/akztC7H2IsEKaq4i@sirena.org.uk
Link: https://patch.msgid.link/20260707162935.1900874-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 8754c99c22f2fe8d9faced156f636c44298244f8..70dceb20dfada18ed797652cbb112f3b76e12d32 100644 (file)
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1356,7 +1356,7 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
                                   enum kvm_pgtable_prot prot, enum kvm_pgtable_walk_flags flags)
 {
        kvm_pte_t xn = 0, set = 0, clr = 0;
-       s8 level = TLBI_TTL_UNKNOWN;
+       s8 level;
        int ret;
 
        if (prot & KVM_PTE_LEAF_ATTR_HI_SW)
@@ -1379,7 +1379,8 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
 
        ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level, flags);
        if (!ret || ret == -EAGAIN)
-               kvm_call_hyp(__kvm_tlb_flush_vmid_ipa_nsh, pgt->mmu, addr, level);
+               kvm_call_hyp(__kvm_tlb_flush_vmid_ipa_nsh, pgt->mmu, addr,
+                            (ret == -EAGAIN) ? TLBI_TTL_UNKNOWN : level);
        return ret;
 }