summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/reset.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kvm/reset.c')
-rw-r--r--arch/arm64/kvm/reset.c108
1 files changed, 105 insertions, 3 deletions
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index e37c78bbe1ca..b72a3dd56204 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;
+}