Although we emit a "SANITY CHECK" warning and taint the kernel if we
detect a CPU mismatch for AArch32 support at EL1, we still online the
CPU with disastrous consequences for any running 32-bit VMs.
Introduce a capability for AArch32 support at EL1 so that late onlining
of incompatible CPUs is forbidden.
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200421142922.18950-4-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
#define ARM64_HAS_AMU_EXTN 51
#define ARM64_HAS_ADDRESS_AUTH 52
#define ARM64_HAS_GENERIC_AUTH 53
+#define ARM64_HAS_32BIT_EL1 54
-#define ARM64_NCAPS 54
+#define ARM64_NCAPS 55
#endif /* __ASM_CPUCAPS_H */
#define ID_AA64PFR0_ASIMD_NI 0xf
#define ID_AA64PFR0_ASIMD_SUPPORTED 0x0
#define ID_AA64PFR0_EL1_64BIT_ONLY 0x1
+#define ID_AA64PFR0_EL1_32BIT_64BIT 0x2
#define ID_AA64PFR0_EL0_64BIT_ONLY 0x1
#define ID_AA64PFR0_EL0_32BIT_64BIT 0x2
.field_pos = ID_AA64PFR0_EL0_SHIFT,
.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
},
+#ifdef CONFIG_KVM
+ {
+ .desc = "32-bit EL1 Support",
+ .capability = ARM64_HAS_32BIT_EL1,
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .matches = has_cpuid_feature,
+ .sys_reg = SYS_ID_AA64PFR0_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64PFR0_EL1_SHIFT,
+ .min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT,
+ },
+#endif
{
.desc = "Kernel page table isolation (KPTI)",
.capability = ARM64_UNMAP_KERNEL_AT_EL0,
PSR_AA32_I_BIT | PSR_AA32_F_BIT),
};
-static bool cpu_has_32bit_el1(void)
-{
- u64 pfr0;
-
- pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
- return !!(pfr0 & 0x20);
-}
-
/**
* kvm_arch_vm_ioctl_check_extension
*
switch (ext) {
case KVM_CAP_ARM_EL1_32BIT:
- r = cpu_has_32bit_el1();
+ r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1);
break;
case KVM_CAP_GUEST_DEBUG_HW_BPS:
r = get_num_brps();
switch (vcpu->arch.target) {
default:
if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
- if (!cpu_has_32bit_el1())
+ if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1))
goto out;
cpu_reset = &default_regs_reset32;
} else {