diff options
Diffstat (limited to 'arch/arm64/kvm/reset.c')
| -rw-r--r-- | arch/arm64/kvm/reset.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 2bf41e007390..96b3f50101bc 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -34,6 +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 */ @@ -135,6 +138,46 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) 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 |