1 files changed, 105 insertions, 3 deletions

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index e37c78bbe1ca9..b72a3dd562044 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -26,6 +26,7 @@
 
 #include <kvm/arm_arch_timer.h>
 
+#include <asm/cpufeature.h>
 #include <asm/cputype.h>
 #include <asm/ptrace.h>
 #include <asm/kvm_arm.h>
@@ -33,6 +34,9 @@
 #include <asm/kvm_coproc.h>
 #include <asm/kvm_mmu.h>
 
+/* Maximum phys_shift supported for any VM on this host */
+static u32 kvm_ipa_limit;
+
 /*
  * ARMv8 Reset Values
  */
@@ -55,12 +59,12 @@ static bool cpu_has_32bit_el1(void)
 }
 
 /**
- * kvm_arch_dev_ioctl_check_extension
+ * kvm_arch_vm_ioctl_check_extension
  *
  * We currently assume that the number of HW registers is uniform
  * across all CPUs (see cpuinfo_sanity_check).
  */
-int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
+int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r;
 
@@ -82,9 +86,11 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_VCPU_ATTRIBUTES:
-	case KVM_CAP_VCPU_EVENTS:
 		r = 1;
 		break;
+	case KVM_CAP_ARM_VM_IPA_SIZE:
+		r = kvm_ipa_limit;
+		break;
 	default:
 		r = 0;
 	}
@@ -133,3 +139,99 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 	/* Reset timer */
 	return kvm_timer_vcpu_reset(vcpu);
 }
+
+void kvm_set_ipa_limit(void)
+{
+	unsigned int ipa_max, pa_max, va_max, parange;
+
+	parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 0x7;
+	pa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
+
+	/* Clamp the IPA limit to the PA size supported by the kernel */
+	ipa_max = (pa_max > PHYS_MASK_SHIFT) ? PHYS_MASK_SHIFT : pa_max;
+	/*
+	 * Since our stage2 table is dependent on the stage1 page table code,
+	 * we must always honor the following condition:
+	 *
+	 *  Number of levels in Stage1 >= Number of levels in Stage2.
+	 *
+	 * So clamp the ipa limit further down to limit the number of levels.
+	 * Since we can concatenate upto 16 tables at entry level, we could
+	 * go upto 4bits above the maximum VA addressible with the current
+	 * number of levels.
+	 */
+	va_max = PGDIR_SHIFT + PAGE_SHIFT - 3;
+	va_max += 4;
+
+	if (va_max < ipa_max)
+		ipa_max = va_max;
+
+	/*
+	 * If the final limit is lower than the real physical address
+	 * limit of the CPUs, report the reason.
+	 */
+	if (ipa_max < pa_max)
+		pr_info("kvm: Limiting the IPA size due to kernel %s Address limit\n",
+			(va_max < pa_max) ? "Virtual" : "Physical");
+
+	WARN(ipa_max < KVM_PHYS_SHIFT,
+	     "KVM IPA limit (%d bit) is smaller than default size\n", ipa_max);
+	kvm_ipa_limit = ipa_max;
+	kvm_info("IPA Size Limit: %dbits\n", kvm_ipa_limit);
+}
+
+/*
+ * 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;
+	u32 parange, phys_shift;
+	u8 lvls;
+
+	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
+		return -EINVAL;
+
+	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
+	if (phys_shift) {
+		if (phys_shift > kvm_ipa_limit ||
+		    phys_shift < 32)
+			return -EINVAL;
+	} else {
+		phys_shift = KVM_PHYS_SHIFT;
+	}
+
+	parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 7;
+	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;
+
+	/* Set the vmid bits */
+	vtcr |= (kvm_get_vmid_bits() == 16) ?
+		VTCR_EL2_VS_16BIT :
+		VTCR_EL2_VS_8BIT;
+	kvm->arch.vtcr = vtcr;
+	return 0;
+}