arm64: Rewrite Spectre-v2 mitigation code

The Spectre-v2 mitigation code is pretty unwieldy and hard to maintain.
This is largely due to it being written hastily, without much clue as to
how things would pan out, and also because it ends up mixing policy and
state in such a way that it is very difficult to figure out what's going
on.

Rewrite the Spectre-v2 mitigation so that it clearly separates state from
policy and follows a more structured approach to handling the mitigation.

Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 83415e96b589..fbdd6f3bea7f 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -425,12 +425,12 @@ static int get_kernel_wa_level(u64 regid)
 {
 	switch (regid) {
 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
-		switch (kvm_arm_harden_branch_predictor()) {
-		case KVM_BP_HARDEN_UNKNOWN:
+		switch (arm64_get_spectre_v2_state()) {
+		case SPECTRE_VULNERABLE:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
-		case KVM_BP_HARDEN_WA_NEEDED:
+		case SPECTRE_MITIGATED:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL;
-		case KVM_BP_HARDEN_NOT_REQUIRED:
+		case SPECTRE_UNAFFECTED:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED;
 		}
 		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;