KVM: arm64: Refactor kvm_arm_setup_stage2()

In order to re-use some of the stage 2 setup code at EL2, factor parts
of kvm_arm_setup_stage2() out into separate functions.

No functional change intended.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-23-qperret@google.com

1 files changed, 4 insertions, 38 deletions

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 67f30953d6d0..86d94f616a1e 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -329,19 +329,10 @@ int kvm_set_ipa_limit(void)
 	return 0;
 }
 
-/*
- * Configure the VTCR_EL2 for this VM. The VTCR value is common
- * across all the physical CPUs on the system. We use system wide
- * sanitised values to fill in different fields, except for Hardware
- * Management of Access Flags. HA Flag is set unconditionally on
- * all CPUs, as it is safe to run with or without the feature and
- * the bit is RES0 on CPUs that don't support it.
- */
 int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
 {
-	u64 vtcr = VTCR_EL2_FLAGS, mmfr0;
-	u32 parange, phys_shift;
-	u8 lvls;
+	u64 mmfr0, mmfr1;
+	u32 phys_shift;
 
 	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
 		return -EINVAL;
@@ -361,33 +352,8 @@ int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
 	}
 
 	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
-	parange = cpuid_feature_extract_unsigned_field(mmfr0,
-				ID_AA64MMFR0_PARANGE_SHIFT);
-	if (parange > ID_AA64MMFR0_PARANGE_MAX)
-		parange = ID_AA64MMFR0_PARANGE_MAX;
-	vtcr |= parange << VTCR_EL2_PS_SHIFT;
-
-	vtcr |= VTCR_EL2_T0SZ(phys_shift);
-	/*
-	 * Use a minimum 2 level page table to prevent splitting
-	 * host PMD huge pages at stage2.
-	 */
-	lvls = stage2_pgtable_levels(phys_shift);
-	if (lvls < 2)
-		lvls = 2;
-	vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls);
-
-	/*
-	 * Enable the Hardware Access Flag management, unconditionally
-	 * on all CPUs. The features is RES0 on CPUs without the support
-	 * and must be ignored by the CPUs.
-	 */
-	vtcr |= VTCR_EL2_HA;
+	mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+	kvm->arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);
 
-	/* Set the vmid bits */
-	vtcr |= (kvm_get_vmid_bits() == 16) ?
-		VTCR_EL2_VS_16BIT :
-		VTCR_EL2_VS_8BIT;
-	kvm->arch.vtcr = vtcr;
 	return 0;
 }