KVM: arm64: Account for 52bit when computing maximum OA

Adjust the computation of the max OA to account for 52bit PAs.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

arch/arm64/include/asm/kvm_nested.h

@@ -265,15 +265,18 @@ static inline u64 decode_range_tlbi(u64 val, u64 *range, u16 *asid)
 	return base;
 }
 
-static inline unsigned int ps_to_output_size(unsigned int ps)
+static inline unsigned int ps_to_output_size(unsigned int ps, bool pa52bit)
 {
 	switch (ps) {
 	case 0: return 32;
 	case 1: return 36;
 	case 2: return 40;
 	case 3: return 42;
 	case 4: return 44;
-	case 5:
+	case 5: return 48;
+	case 6: if (pa52bit)
+			return 52;
+		fallthrough;
 	default:
 		return 48;
 	}

arch/arm64/kvm/at.c

@@ -295,7 +295,7 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 	ps = (wi->regime == TR_EL2 ?
 	      FIELD_GET(TCR_EL2_PS_MASK, tcr) : FIELD_GET(TCR_IPS_MASK, tcr));
 
-	wi->max_oa_bits = min(get_kvm_ipa_limit(), ps_to_output_size(ps));
+	wi->max_oa_bits = min(get_kvm_ipa_limit(), ps_to_output_size(ps, wi->pa52bit));
 
 	/* Compute minimal alignment */
 	x = 3 + ia_bits - ((3 - wi->sl) * stride + wi->pgshift);

arch/arm64/kvm/nested.c

@@ -349,7 +349,7 @@ static void vtcr_to_walk_info(u64 vtcr, struct s2_walk_info *wi)
 	wi->sl = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr);
 	/* Global limit for now, should eventually be per-VM */
 	wi->max_oa_bits = min(get_kvm_ipa_limit(),
-			      ps_to_output_size(FIELD_GET(VTCR_EL2_PS_MASK, vtcr)));
+			      ps_to_output_size(FIELD_GET(VTCR_EL2_PS_MASK, vtcr), false));
 }
 
 int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa,