#include <asm/virt.h>
-#define VCPU_WORKAROUND_2_FLAG_SHIFT 0
-#define VCPU_WORKAROUND_2_FLAG (_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)
-
#define ARM_EXIT_WITH_SERROR_BIT 31
#define ARM_EXCEPTION_CODE(x) ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
#define ARM_EXCEPTION_IS_TRAP(x) (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
return vcpu_read_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
}
-static inline bool kvm_arm_get_vcpu_workaround_2_flag(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG;
-}
-
-static inline void kvm_arm_set_vcpu_workaround_2_flag(struct kvm_vcpu *vcpu,
- bool flag)
-{
- if (flag)
- vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
- else
- vcpu->arch.workaround_flags &= ~VCPU_WORKAROUND_2_FLAG;
-}
-
static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu)) {
}
#endif
-DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
-
-static inline int hyp_map_aux_data(void)
-{
- int cpu, err;
-
- for_each_possible_cpu(cpu) {
- u64 *ptr;
-
- ptr = per_cpu_ptr(&arm64_ssbd_callback_required, cpu);
- err = create_hyp_mappings(ptr, ptr + 1, PAGE_HYP);
- if (err)
- return err;
- }
- return 0;
-}
-
#define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr)
/*
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL 0
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL 1
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED 2
+
+/*
+ * Only two states can be presented by the host kernel:
+ * - NOT_REQUIRED: the guest doesn't need to do anything
+ * - NOT_AVAIL: the guest isn't mitigated (it can still use SSBS if available)
+ *
+ * All the other values are deprecated. The host still accepts all
+ * values (they are ABI), but will narrow them to the above two.
+ */
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2 KVM_REG_ARM_FW_REG(2)
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL 0
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN 1
int ssbd_state __read_mostly = ARM64_SSBD_UNKNOWN;
-void __init arm64_enable_wa2_handling(struct alt_instr *alt,
- __le32 *origptr, __le32 *updptr,
- int nr_inst)
-{
- BUG_ON(nr_inst != 1);
- /*
- * Only allow mitigation on EL1 entry/exit and guest
- * ARCH_WORKAROUND_2 handling if the SSBD state allows it to
- * be flipped.
- */
- if (arm64_get_ssbd_state() == ARM64_SSBD_KERNEL)
- *updptr = cpu_to_le32(aarch64_insn_gen_nop());
-}
-
#ifdef CONFIG_ARM64_ERRATUM_1463225
DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
#define KVM_NVHE_ALIAS(sym) __kvm_nvhe_##sym = sym;
/* Alternative callbacks for init-time patching of nVHE hyp code. */
-KVM_NVHE_ALIAS(arm64_enable_wa2_handling);
KVM_NVHE_ALIAS(kvm_patch_vector_branch);
KVM_NVHE_ALIAS(kvm_update_va_mask);
/* Global kernel state accessed by nVHE hyp code. */
-KVM_NVHE_ALIAS(arm64_ssbd_callback_required);
KVM_NVHE_ALIAS(kvm_host_data);
KVM_NVHE_ALIAS(kvm_vgic_global_state);
}
}
- err = hyp_map_aux_data();
- if (err)
- kvm_err("Cannot map host auxiliary data: %d\n", err);
-
return 0;
out_err:
ARM_SMCCC_ARCH_WORKAROUND_2)
cbnz w1, el1_trap
-alternative_cb arm64_enable_wa2_handling
- b wa2_end
-alternative_cb_end
- get_vcpu_ptr x2, x0
- ldr x0, [x2, #VCPU_WORKAROUND_FLAGS]
-
- // Sanitize the argument and update the guest flags
- ldr x1, [sp, #8] // Guest's x1
- clz w1, w1 // Murphy's device:
- lsr w1, w1, #5 // w1 = !!w1 without using
- eor w1, w1, #1 // the flags...
- bfi x0, x1, #VCPU_WORKAROUND_2_FLAG_SHIFT, #1
- str x0, [x2, #VCPU_WORKAROUND_FLAGS]
-
- /* Check that we actually need to perform the call */
- hyp_ldr_this_cpu x0, arm64_ssbd_callback_required, x2
- cbz x0, wa2_end
-
- mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2
- smc #0
-
- /* Don't leak data from the SMC call */
- mov x3, xzr
-wa2_end:
- mov x2, xzr
- mov x1, xzr
-
wa_epilogue:
mov x0, xzr
add sp, sp, #16
return false;
}
-static inline bool __needs_ssbd_off(struct kvm_vcpu *vcpu)
-{
- if (!cpus_have_final_cap(ARM64_SPECTRE_V4))
- return false;
-
- return !(vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG);
-}
-
-static inline void __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu)
-{
- /*
- * The host runs with the workaround always present. If the
- * guest wants it disabled, so be it...
- */
- if (__needs_ssbd_off(vcpu) &&
- __hyp_this_cpu_read(arm64_ssbd_callback_required))
- arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 0, NULL);
-}
-
-static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu)
-{
- /*
- * If the guest has disabled the workaround, bring it back on.
- */
- if (__needs_ssbd_off(vcpu) &&
- __hyp_this_cpu_read(arm64_ssbd_callback_required))
- arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 1, NULL);
-}
-
static inline void __kvm_unexpected_el2_exception(void)
{
unsigned long addr, fixup;
__debug_switch_to_guest(vcpu);
- __set_guest_arch_workaround_state(vcpu);
-
do {
/* Jump in the fire! */
exit_code = __guest_enter(vcpu, host_ctxt);
/* And we're baaack! */
} while (fixup_guest_exit(vcpu, &exit_code));
- __set_host_arch_workaround_state(vcpu);
-
__sysreg_save_state_nvhe(guest_ctxt);
__sysreg32_save_state(vcpu);
__timer_disable_traps(vcpu);
sysreg_restore_guest_state_vhe(guest_ctxt);
__debug_switch_to_guest(vcpu);
- __set_guest_arch_workaround_state(vcpu);
-
do {
/* Jump in the fire! */
exit_code = __guest_enter(vcpu, host_ctxt);
/* And we're baaack! */
} while (fixup_guest_exit(vcpu, &exit_code));
- __set_host_arch_workaround_state(vcpu);
-
sysreg_save_guest_state_vhe(guest_ctxt);
__deactivate_traps(vcpu);
}
break;
case ARM_SMCCC_ARCH_WORKAROUND_2:
- switch (kvm_arm_have_ssbd()) {
- case KVM_SSBD_FORCE_DISABLE:
- case KVM_SSBD_UNKNOWN:
+ switch (arm64_get_ssbd_state()) {
+ case ARM64_SSBD_FORCE_DISABLE:
+ case ARM64_SSBD_UNKNOWN:
break;
- case KVM_SSBD_KERNEL:
- val = SMCCC_RET_SUCCESS;
- break;
- case KVM_SSBD_FORCE_ENABLE:
- case KVM_SSBD_MITIGATED:
+ case ARM64_SSBD_KERNEL:
+ case ARM64_SSBD_FORCE_ENABLE:
+ case ARM64_SSBD_MITIGATED:
val = SMCCC_RET_NOT_REQUIRED;
break;
}
}
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
- switch (kvm_arm_have_ssbd()) {
- case KVM_SSBD_FORCE_DISABLE:
- return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
- case KVM_SSBD_KERNEL:
- return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL;
- case KVM_SSBD_FORCE_ENABLE:
- case KVM_SSBD_MITIGATED:
+ switch (arm64_get_ssbd_state()) {
+ case ARM64_SSBD_FORCE_ENABLE:
+ case ARM64_SSBD_MITIGATED:
+ case ARM64_SSBD_KERNEL:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
- case KVM_SSBD_UNKNOWN:
+ case ARM64_SSBD_UNKNOWN:
+ case ARM64_SSBD_FORCE_DISABLE:
default:
- return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN;
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
}
}
val = kvm_psci_version(vcpu, vcpu->kvm);
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
- val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
- break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
-
- if (val == KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL &&
- kvm_arm_get_vcpu_workaround_2_flag(vcpu))
- val |= KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED;
break;
default:
return -ENOENT;
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED))
return -EINVAL;
- wa_level = val & KVM_REG_FEATURE_LEVEL_MASK;
-
- if (get_kernel_wa_level(reg->id) < wa_level)
- return -EINVAL;
-
/* The enabled bit must not be set unless the level is AVAIL. */
- if (wa_level != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL &&
- wa_level != val)
+ if ((val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED) &&
+ (val & KVM_REG_FEATURE_LEVEL_MASK) != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL)
return -EINVAL;
- /* Are we finished or do we need to check the enable bit ? */
- if (kvm_arm_have_ssbd() != KVM_SSBD_KERNEL)
- return 0;
-
/*
- * If this kernel supports the workaround to be switched on
- * or off, make sure it matches the requested setting.
+ * Map all the possible incoming states to the only two we
+ * really want to deal with.
*/
- switch (wa_level) {
- case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL:
- kvm_arm_set_vcpu_workaround_2_flag(vcpu,
- val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED);
+ switch (val & KVM_REG_FEATURE_LEVEL_MASK) {
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN:
+ wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED:
- kvm_arm_set_vcpu_workaround_2_flag(vcpu, true);
+ wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
break;
+ default:
+ return -EINVAL;
}
+ /*
+ * We can deal with NOT_AVAIL on NOT_REQUIRED, but not the
+ * other way around.
+ */
+ if (get_kernel_wa_level(reg->id) < wa_level)
+ return -EINVAL;
+
return 0;
default:
return -ENOENT;
vcpu->arch.reset_state.reset = false;
}
- /* Default workaround setup is enabled (if supported) */
- if (kvm_arm_have_ssbd() == KVM_SSBD_KERNEL)
- vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
-
/* Reset timer */
ret = kvm_timer_vcpu_reset(vcpu);
out:
projects / linux.git / commitdiff