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

PATCH Applied Marc Zyngier 1 participant 2 messages Jul 7

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Marc Zyngier

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PATCH 1/1 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 <[email protected]>
Reviewed-by Oliver Upton <[email protected]>
Signed-off-by Marc Zyngier <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
---
 arch/arm64/kvm/hyp/pgtable.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
arch/arm64/kvm/hyp/pgtable.c +3 -2
index 8754c99c22f2f..70dceb20dfada 100644
@@ -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;
 }
Signature · 1 line
2.47.3
author maintainer Applied
#1 lore raw
Quoted 6 lines · Marc Zyngier

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.

Applied to fixes, thanks!

[1/1] KVM: arm64: Fix propagation of TLBI level in kvm_pgtable_stage2_relax_perms()

      commit: 8d187d4b33c262c0f3e44842553521151d8629e8

Cheers,

	M.
Signature · 1 line
Without deviation from the norm, progress is not possible.